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OTTL Functions

The following functions are intended to be used in implementations of the OpenTelemetry Transformation Language that interact with OTel data via the Collector's internal data model, pdata.

This document contains documentation for both types of OTTL functions:

  • Editors that transform telemetry.
  • Converters that provide utilities for transforming telemetry.

Design principles

For the standard OTTL functions described in this document, we specify design principles to ensure they are always secure and safe for use:

  • Built-in OTTL functions may not access the file system, network, or any other I/O devices.
  • Built-in OTTL functions may share information only through their parameters and results.
  • Built-in OTTL functions must be terminating; they must not loop forever.

OTTL functions are implemented in Go, and so are only limited by what can be implemented in a Go program. User-defined OTTL functions may therefore not adhere the above principles.

Working with functions

Functions generally expect specific types to be returned by Paths. For these functions, if that type is not returned or if nil is returned, the function will error. Some functions are able to handle different types and will generally convert those types to their desired type. In these situations the function will error if it does not know how to do the conversion. Use ErrorMode to determine how the Statement handles these errors. See the component-specific guides for how each uses error mode:

Editors

Editors are what OTTL uses to transform telemetry.

Editors:

  • Are allowed to transform telemetry. When a Function is invoked the expectation is that the underlying telemetry is modified in some way.
  • May have side effects. Some Functions may generate telemetry and add it to the telemetry payload to be processed in this batch.
  • May return values. Although not common and not required, Functions may return values.

Available Editors:

append

append(target, Optional[value], Optional[values])

The append function appends single or multiple string values to target. append converts scalar values into an array if the field exists but is not an array, and creates an array containing the provided values if the field doesn’t exist.

Resulting field is always of type pcommon.Slice and will not convert the types of existing or new items in the slice. This means that it is possible to create a slice whose elements have different types. Be careful when using append to set attribute values, as this will produce values that are not possible to create through OpenTelemetry APIs according to the OpenTelemetry specification.

  • append(attributes["tags"], "prod")
  • append(attributes["tags"], values = ["staging", "staging:east"])
  • append(attributes["tags_copy"], attributes["tags"])

delete_key

delete_key(target, key)

The delete_key function removes a key from a pcommon.Map

target is a path expression to a pcommon.Map type field. key is a string that is a key in the map.

The key will be deleted from the map.

Examples:

  • delete_key(attributes, "http.request.header.authorization")

  • delete_key(resource.attributes, "http.request.header.authorization")

delete_matching_keys

delete_matching_keys(target, pattern)

The delete_matching_keys function removes all keys from a pcommon.Map that match a regex pattern.

target is a path expression to a pcommon.Map type field. pattern is a regex string.

All keys that match the pattern will be deleted from the map.

Examples:

  • delete_matching_keys(attributes, "(?i).*password.*")

  • delete_matching_keys(resource.attributes, "(?i).*password.*")

keep_matching_keys

keep_matching_keys(target, pattern)

The keep_matching_keys function keeps all keys from a pcommon.Map that match a regex pattern.

target is a path expression to a pcommon.Map type field. pattern is a regex string.

All keys that match the pattern will remain in the map, while non matching keys will be removed.

Examples:

  • keep_matching_keys(attributes, "(?i).*version.*")

  • keep_matching_keys(resource.attributes, "(?i).*version.*")

flatten

flatten(target, Optional[prefix], Optional[depth])

The flatten function flattens a pcommon.Map by moving items from nested maps to the root.

target is a path expression to a pcommon.Map type field. prefix is an optional string. depth is an optional non-negative int.

For example, the following map

{
  "name": "test",
  "address": {
    "street": "first",
    "house": 1234
  },
  "occupants": ["user 1", "user 2"]
}

is converted to

{
    "name": "test",
    "address.street": "first",
    "address.house": 1234,
    "occupants.0": "user 1",
    "occupants.1": "user 2"
}

If prefix is supplied, it will be appended to the start of the new keys. This can help you namespace the changes. For example, if in the above example a prefix of app was configured, the result would be

{
    "app.name": "test",
    "app.address.street": "first",
    "app.address.house": 1234,
    "app.occupants.0": "user 1",
    "app.occupants.1": "user 2"
}

If depth is supplied, the function will only flatten nested maps up to that depth. For example, if a depth of 2 was configured, the following map

{
  "0": {
    "1": {
      "2": {
        "3": {
          "4": "value"
        }
      }
    }
  }
}

the result would be

{
  "0.1.2": {
    "3": {
      "4": "value"
    }
  }
}

A depth of 0 means that no flattening will occur.

Examples:

  • flatten(attributes)

  • flatten(cache, "k8s", 4)

  • flatten(body, depth=2)

keep_keys

keep_keys(target, keys[])

The keep_keys function removes all keys from the pcommon.Map that do not match one of the supplied keys.

target is a path expression to a pcommon.Map type field. keys is a slice of one or more strings.

The map will be changed to only contain the keys specified by the list of strings.

Examples:

  • keep_keys(attributes, ["http.method"])

  • keep_keys(resource.attributes, ["http.method", "http.route", "http.url"])

limit

limit(target, limit, priority_keys[])

The limit function reduces the number of elements in a pcommon.Map to be no greater than the limit.

target is a path expression to a pcommon.Map type field. limit is a non-negative integer. priority_keys is a list of strings of attribute keys that won't be dropped during limiting.

The number of priority keys must be less than the supplied limit.

The map will be mutated such that the number of items does not exceed the limit. The map is not copied or reallocated.

Which items are dropped is random, provide keys in priority_keys to preserve required keys.

Examples:

  • limit(attributes, 100, [])

  • limit(resource.attributes, 50, ["http.host", "http.method"])

merge_maps

merge_maps(target, source, strategy)

The merge_maps function merges the source map into the target map using the supplied strategy to handle conflicts.

target is a pcommon.Map type field. source is a pcommon.Map type field. strategy is a string that must be one of insert, update, or upsert.

If strategy is:

  • insert: Insert the value from source into target where the key does not already exist.
  • update: Update the entry in target with the value from source where the key does exist.
  • upsert: Performs insert or update. Insert the value from source into target where the key does not already exist and update the entry in target with the value from source where the key does exist.

merge_maps is a special case of the set function. If you need to completely override target, use set instead.

Examples:

  • merge_maps(attributes, ParseJSON(body), "upsert")

  • merge_maps(attributes, ParseJSON(attributes["kubernetes"]), "update")

  • merge_maps(attributes, resource.attributes, "insert")

replace_all_matches

replace_all_matches(target, pattern, replacement, Optional[function], Optional[replacementFormat])

The replace_all_matches function replaces any matching string value with the replacement string.

target is a path expression to a pcommon.Map type field. pattern is a string following filepath.Match syntax. replacement is either a path expression to a string telemetry field or a literal string. function is an optional argument that can take in any Converter that accepts a (replacement) string and returns a string. An example is a hash function that replaces any matching string with the hash value of replacement. replacementFormat is an optional string argument that specifies the format of the replacement. It must contain exactly one %s format specifier as shown in the example below. No other format specifiers are supported.

Each string value in target that matches pattern will get replaced with replacement. Non-string values are ignored.

Examples:

  • replace_all_matches(attributes, "/user/*/list/*", "/user/{userId}/list/{listId}")
  • replace_all_matches(attributes, "/user/*/list/*", "/user/{userId}/list/{listId}", SHA256, "/user/%s")

replace_all_patterns

replace_all_patterns(target, mode, regex, replacement, Optional[function], Optional[replacementFormat])

The replace_all_patterns function replaces any segments in a string value or key that match the regex pattern with the replacement string.

target is a path expression to a pcommon.Map type field. regex is a regex string indicating a segment to replace. replacement is either a path expression to a string telemetry field or a literal string.

mode determines whether the match and replace will occur on the map's value or key. Valid values are key and value.

If one or more sections of target match regex they will get replaced with replacement.

The replacement string can refer to matched groups using regexp.Expand syntax. replacementFormat is an optional string argument that specifies the format of the replacement. It must contain exactly one %s format specifier as shown in the example below. No other format specifiers are supported.

The function is an optional argument that can take in any Converter that accepts a (replacement) string and returns a string. An example is a hash function that replaces any matching regex pattern with the hash value of replacement.

Examples:

  • replace_all_patterns(attributes, "value", "/account/\\d{4}", "/account/{accountId}")
  • replace_all_patterns(attributes, "key", "/account/\\d{4}", "/account/{accountId}")
  • replace_all_patterns(attributes, "key", "^kube_([0-9A-Za-z]+_)", "k8s.$$1.")
  • replace_all_patterns(attributes, "key", "^kube_([0-9A-Za-z]+_)", "$$1.")
  • replace_all_patterns(attributes, "key", "^kube_([0-9A-Za-z]+_)", "$$1.", SHA256, "k8s.%s")

Note that when using OTTL within the collector's configuration file, $ must be escaped to $$ to bypass environment variable substitution logic. To input a literal $ from the configuration file, use $$$. If using OTTL outside of collector configuration, $ should not be escaped and a literal $ can be entered using $$.

replace_match

replace_match(target, pattern, replacement, Optional[function], Optional[replacementFormat])

The replace_match function allows replacing entire strings if they match a glob pattern.

target is a path expression to a telemetry field. pattern is a string following filepath.Match syntax. replacement is either a path expression to a string telemetry field or a literal string. replacementFormat is an optional string argument that specifies the format of the replacement. It must contain exactly one %s format specifier as shown in the example below. No other format specifiers are supported.

If target matches pattern it will get replaced with replacement.

The function is an optional argument that can take in any Converter that accepts a (replacement) string and returns a string. An example is a hash function that replaces any matching glob pattern with the hash value of replacement.

Examples:

  • replace_match(attributes["http.target"], "/user/*/list/*", "/user/{userId}/list/{listId}")
  • replace_match(attributes["http.target"], "/user/*/list/*", "/user/{userId}/list/{listId}", SHA256, "/user/%s")

replace_pattern

replace_pattern(target, regex, replacement, Optional[function], Optional[replacementFormat])

The replace_pattern function allows replacing all string sections that match a regex pattern with a new value.

target is a path expression to a telemetry field. regex is a regex string indicating a segment to replace. replacement is either a path expression to a string telemetry field or a literal string.

If one or more sections of target match regex they will get replaced with replacement.

The replacement string can refer to matched groups using regexp.Expand syntax. replacementFormat is an optional string argument that specifies the format of the replacement. It must contain exactly one %s format specifier as shown in the example below. No other format specifiers are supported

The function is an optional argument that can take in any Converter that accepts a (replacement) string and returns a string. An example is a hash function that replaces a matching regex pattern with the hash value of replacement.

Examples:

  • replace_pattern(resource.attributes["process.command_line"], "password\\=[^\\s]*(\\s?)", "password=***")
  • replace_pattern(name, "^kube_([0-9A-Za-z]+_)", "k8s.$$1.")
  • replace_pattern(name, "^kube_([0-9A-Za-z]+_)", "$$1.", SHA256, "k8s.%s")

Note that when using OTTL within the collector's configuration file, $ must be escaped to $$ to bypass environment variable substitution logic. To input a literal $ from the configuration file, use $$$. If using OTTL outside of collector configuration, $ should not be escaped and a literal $ can be entered using $$.

set

set(target, value)

The set function allows users to set a telemetry field using a value.

target is a path expression to a telemetry field. value is any value type. If value resolves to nil, e.g. it references an unset map value, there will be no action.

How the underlying telemetry field is updated is decided by the path expression implementation provided by the user to the ottl.ParseStatements.

Examples:

  • set(attributes["http.path"], "/foo")

  • set(name, attributes["http.route"])

  • set(trace_state["svc"], "example")

  • set(attributes["source"], trace_state["source"])

truncate_all

truncate_all(target, limit)

The truncate_all function truncates all string values in a pcommon.Map so that none are longer than the limit.

target is a path expression to a pcommon.Map type field. limit is a non-negative integer.

The map will be mutated such that the number of characters in all string values is less than or equal to the limit. Non-string values are ignored.

Examples:

  • truncate_all(attributes, 100)

  • truncate_all(resource.attributes, 50)

Converters

Converters are pure functions that take OTTL values as input and output a single value for use within a statement. Unlike functions, they do not modify any input telemetry and always return a value.

Available Converters:

Base64Decode (Deprecated)

This function has been deprecated. Please use the Decode function instead.

Base64Decode(value)

The Base64Decode Converter takes a base64 encoded string and returns the decoded string.

value is a valid base64 encoded string.

Examples:

  • Base64Decode("aGVsbG8gd29ybGQ=")

  • Base64Decode(attributes["encoded field"])

Decode

Decode(value, encoding)

The Decode Converter takes a string or byte array encoded with the specified encoding and returns the decoded string.

value is a valid encoded string or byte array. encoding is a valid encoding name included in the IANA encoding index.

Examples:

  • Decode("aGVsbG8gd29ybGQ=", "base64")

  • Decode(attributes["encoded field"], "us-ascii")

Concat

Concat(values[], delimiter)

The Concat Converter takes a sequence of values and a delimiter and concatenates their string representation. Unsupported values, such as lists or maps that may substantially increase payload size, are not added to the resulting string.

values is a list of values. It supports paths, primitive values, and byte slices (such as trace IDs or span IDs).

delimiter is a string value that is placed between strings during concatenation. If no delimiter is desired, then simply pass an empty string.

Examples:

  • Concat([attributes["http.method"], attributes["http.path"]], ": ")

  • Concat([name, 1], " ")

  • Concat(["HTTP method is: ", attributes["http.method"]], "")

ConvertCase

ConvertCase(target, toCase)

The ConvertCase Converter converts the target string into the desired case toCase.

target is a string. toCase is a string.

If the target is not a string or does not exist, the ConvertCase Converter will return an error.

toCase can be:

  • lower: Converts the target string to lowercase (e.g. MY_METRIC to my_metric)
  • upper: Converts the target string to uppercase (e.g. my_metric to MY_METRIC)
  • snake: Converts the target string to snakecase (e.g. myMetric to my_metric)
  • camel: Converts the target string to camelcase (e.g. my_metric to MyMetric)

If toCase is any value other than the options above, the ConvertCase Converter will return an error during collector startup.

Examples:

  • ConvertCase(metric.name, "snake")

ConvertAttributesToElementsXML

ConvertAttributesToElementsXML(target, Optional[xpath])

The ConvertAttributesToElementsXML Converter returns an edited version of an XML string where attributes are converted into child elements.

target is a Getter that returns a string. This string should be in XML format. If target is not a string, nil, or cannot be parsed as XML, ConvertAttributesToElementsXML will return an error.

xpath (optional) is a string that specifies an XPath expression that selects one or more elements. Attributes will only be converted within the result(s) of the xpath.

For example, <a foo="bar"><b>baz</b></a> will be converted to <a><b>baz</b><foo>bar</foo></a>.

Examples:

Convert all attributes in a document

  • ConvertAttributesToElementsXML(body)

Convert only attributes within "Record" elements

  • ConvertAttributesToElementsXML(body, "/Log/Record")

ConvertTextToElementsXML

ConvertTextToElementsXML(target, Optional[xpath], Optional[elementName])

The ConvertTextToElementsXML Converter returns an edited version of an XML string where all text belongs to a dedicated element.

target is a Getter that returns a string. This string should be in XML format. If target is not a string, nil, or cannot be parsed as XML, ConvertTextToElementsXML will return an error.

xpath (optional) is a string that specifies an XPath expression that selects one or more elements. Content will only be converted within the result(s) of the xpath. The default is /.

elementName (optional) is a string that is used for any element tags that are created to wrap content. The default is "value".

For example, <a><b>foo</b>bar</a> will be converted to <a><b>foo</b><value>bar</value></a>.

Examples:

Ensure all text content in a document is wrapped in a dedicated element

  • ConvertTextToElementsXML(body)

Use a custom name for any new elements

  • ConvertTextToElementsXML(body, elementName = "custom")

Convert only part of the document

  • ConvertTextToElementsXML(body, "/some/part/", "value")

Day

Day(value)

The Day Converter returns the day component from the specified time using the Go stdlib time.Day function.

value is a time.Time. If value is another type, an error is returned.

The returned type is int64.

Examples:

  • Day(Now())

Double

The Double Converter converts an inputted value into a double.

The returned type is float64.

The input value types:

  • float64. returns the value without changes.
  • string. Tries to parse a double from string. If it fails then nil will be returned.
  • bool. If value is true, then the function will return 1 otherwise 0.
  • int64. The function converts the integer to a double.

If value is another type or parsing failed nil is always returned.

The value is either a path expression to a telemetry field to retrieve or a literal.

Examples:

  • Double(attributes["http.status_code"])

  • Double("2.0")

Duration

Duration(duration)

The Duration Converter takes a string representation of a duration and converts it to a Golang time.duration.

duration is a string. Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".

If either duration is nil or is in a format that cannot be converted to Golang time.duration, an error is returned.

Examples:

  • Duration("3s")
  • Duration("333ms")
  • Duration("1000000h")

ExtractPatterns

ExtractPatterns(target, pattern)

The ExtractPatterns Converter returns a pcommon.Map struct that is a result of extracting named capture groups from the target string. If not matches are found then an empty pcommon.Map is returned.

target is a Getter that returns a string. pattern is a regex string.

If target is not a string or nil ExtractPatterns will return an error. If pattern does not contain at least 1 named capture group then ExtractPatterns will error on startup.

Examples:

  • ExtractPatterns(attributes["k8s.change_cause"], "GIT_SHA=(?P<git.sha>\w+)")

  • ExtractPatterns(body, "^(?P<timestamp>\\w+ \\w+ [0-9]+:[0-9]+:[0-9]+) (?P<hostname>([A-Za-z0-9-_]+)) (?P<process>\\w+)(\\[(?P<pid>\\d+)\\])?: (?P<message>.*)$")

ExtractGrokPatterns

ExtractGrokPatterns(target, pattern, Optional[namedCapturesOnly], Optional[patternDefinitions])

The ExtractGrokPatterns Converter parses unstructured data into a format that is structured and queryable. It returns a pcommon.Map struct that is a result of extracting named capture groups from the target string. If no matches are found then an empty pcommon.Map is returned.

  • target is a Getter that returns a string.
  • pattern is a grok pattern string.
  • namedCapturesOnly (optional) specifies if non-named captures should be returned.
  • patternDefinitions (optional) is a list of custom pattern definition strings used inside pattern in the form of PATTERN_NAME=PATTERN. This parameter lets you define your own custom patterns to improve readability when the extracted pattern is not part of the default set or when you need custom naming.

If target is not a string or nil ExtractGrokPatterns returns an error. If pattern does not contain at least 1 named capture group and namedCapturesOnly is set to true then ExtractPatterns errors on startup.

Parsing is done using Elastic Go-Grok library. Grok is a regular expression dialect that supports reusable aliased expressions. It sits on re2 regex library so any valid re2 expressions are valid in grok. Grok uses this regular expression language to allow naming existing patterns and combining them into more complex patterns that match your fields

Pattern can be specified in either of these forms:

  • %{SYNTAX} - e.g {NUMBER}
  • %{SYNTAX:ID} - e.g {NUMBER:MY_AGE}
  • %{SYNTAX:ID:TYPE} - e.g {NUMBER:MY_AGE:INT}

Where SYNTAX is a pattern that will match your text, ID is identifier you give to the piece of text being matched and TYPE data type you want to cast your named field. Supported types are int, long, double, float and boolean

The Elastic Go-Grok ships with numerous predefined grok patterns that simplify working with grok. In collector Complete set is included consisting of a default set and all additional sets adding product/tool specific capabilities (like aws or java patterns).

Default set consists of:

Name Example
WORD "hello", "world123", "test_data"
NOTSPACE "example", "text-with-dashes", "12345"
SPACE " ", "\t", " "
INT "123", "-456", "+789"
NUMBER "123", "456.789", "-0.123"
BOOL "true", "false", "true"
BASE10NUM "123", "-123.456", "0.789"
BASE16NUM "1a2b", "0x1A2B", "-0x1a2b3c"
BASE16FLOAT "0x1.a2b3", "-0x1A2B3C.D"
POSINT "123", "456", "789"
NONNEGINT "0", "123", "456"
GREEDYDATA "anything goes", "literally anything", "123 #@!"
QUOTEDSTRING ""This is a quote"", "'single quoted'"
UUID "123e4567-e89b-12d3-a456-426614174000"
URN "urn:isbn:0451450523", "urn:ietf:rfc:2648"

and many more. Complete list can be found here.

Examples:

  • Uses regex pattern with named captures to extract:

    ExtractGrokPatterns(attributes["k8s.change_cause"], "GIT_SHA=(?P<git.sha>\w+)")

  • Uses regex pattern with named captures to extract:

    ExtractGrokPatterns(body, "^(?P<timestamp>\\w+ \\w+ [0-9]+:[0-9]+:[0-9]+) (?P<hostname>([A-Za-z0-9-_]+)) (?P<process>\\w+)(\\[(?P<pid>\\d+)\\])?: (?P<message>.*)$")

  • Uses URI from default set to extract URI and includes only named captures:

    ExtractGrokPatterns(body, "%{URI}", true)

  • Uses more complex pattern consisting of elements from default set and includes only named captures:

    ExtractGrokPatterns(body, "%{DATESTAMP:timestamp} %{TZ:event.timezone} %{DATA:user.name} %{GREEDYDATA:postgresql.log.connection_id} %{POSINT:process.pid:int}", true)

  • Uses LOGLINE pattern defined in patternDefinitions passed as last argument:

    ExtractGrokPatterns(body, "%{LOGLINE}", true, ["LOGLINE=%{DATESTAMP:timestamp} %{TZ:event.timezone} %{DATA:user.name} %{GREEDYDATA:postgresql.log.connection_id} %{POSINT:process.pid:int}"])

  • Add custom patterns to parse the password from /etc/passwd and making pattern readable:

    • pattern: %{USERNAME:user.name}:%{PASSWORD:user.password}:%{USERINFO}

    • patternDefinitions:

      • PASSWORD=%{WORD}
      • USERINFO=%{GREEDYDATA}

      Note that USERNAME is in the default pattern set and does not need to be redefined.

    • Target: smith:pass123:1001:1000:J Smith,1234,(234)567-8910,(234)567-1098,email:/home/smith:/bin/sh

    • Return values:

      • user.name: smith
      • user.password: pass123

FNV

FNV(value)

The FNV Converter converts the value to an FNV hash/digest.

The returned type is int64.

value is either a path expression to a string telemetry field or a literal string. If value is another type an error is returned.

If an error occurs during hashing it will be returned.

Examples:

  • FNV(attributes["device.name"])

  • FNV("name")

Format

Format(formatString, []formatArguments)

The Format Converter takes the given format string and formats it using fmt.Sprintf and the given arguments.

formatString is a string. formatArguments is an array of values.

If the formatString is not a string or does not exist, the Format Converter will return an error. If any of the formatArgs are incorrect (e.g. missing, or an incorrect type for the corresponding format specifier), then a string will still be returned, but with Go's default error handling for fmt.Sprintf.

Format specifiers that can be used in formatString are documented in Go's fmt package documentation

Examples:

  • Format("%02d", [attributes["priority"]])
  • Format("%04d-%02d-%02d", [Year(Now()), Month(Now()), Day(Now())])
  • Format("%s/%s/%04d-%02d-%02d.log", [attributes["hostname"], body["program"], Year(Now()), Month(Now()), Day(Now())])

GetXML

GetXML(target, xpath)

The GetXML Converter returns an XML string with selected elements.

target is a Getter that returns a string. This string should be in XML format. If target is not a string, nil, or is not valid xml, GetXML will return an error.

xpath is a string that specifies an XPath expression that selects one or more elements. Currently, this converter only supports selecting elements.

Examples:

Get all elements at the root of the document with tag "a"

  • GetXML(body, "/a")

Gel all elements anywhere in the document with tag "a"

  • GetXML(body, "//a")

Get the first element at the root of the document with tag "a"

  • GetXML(body, "/a[1]")

Get all elements in the document with tag "a" that have an attribute "b" with value "c"

  • GetXML(body, "//a[@b='c']")

Hex

Hex(value)

The Hex converter converts the value to its hexadecimal representation.

The returned type is string representation of the hexadecimal value.

The input value types:

  • float64 (1.1 will result to 0x3ff199999999999a)
  • string ("1" will result in 0x31)
  • bool (true will result in 0x01; false to 0x00)
  • int64 (12 will result in 0xC)
  • []byte (without any changes - 0x02 will result to 0x02)

If value is another type or parsing failed nil is always returned.

The value is either a path expression to a telemetry field to retrieve or a literal.

Examples:

  • Hex(attributes["http.status_code"])

  • Hex(2.0)

Hour

Hour(value)

The Hour Converter returns the hour from the specified time. The Converter uses the time.Hour function.

value is a time.Time. If value is another type an error is returned.

The returned type is int64.

Examples:

  • Hour(Now())

Hours

Hours(value)

The Hours Converter returns the duration as a floating point number of hours.

value is a time.Duration. If value is another type an error is returned.

The returned type is float64.

Examples:

  • Hours(Duration("1h"))

InsertXML

InsertXML(target, xpath, value)

The InsertXML Converter returns an edited version of an XML string with child elements added to selected elements.

target is a Getter that returns a string. This string should be in XML format and represents the document which will be modified. If target is not a string, nil, or is not valid xml, InsertXML will return an error.

xpath is a string that specifies an XPath expression that selects one or more elements.

value is a Getter that returns a string. This string should be in XML format and represents the document which will be inserted into target. If value is not a string, nil, or is not valid xml, InsertXML will return an error.

Examples:

Add an element "foo" to the root of the document

  • InsertXML(body, "/", "<foo/>")

Add an element "bar" to any element called "foo"

  • InsertXML(body, "//foo", "<bar/>")

Fetch and insert an xml document into another

  • InsertXML(body, "/subdoc", attributes["subdoc"])

Int

Int(value)

The Int Converter converts the value to int type.

The returned type is int64.

The input value types:

  • float64. Fraction is discharged (truncation towards zero).
  • string. Trying to parse an integer from string if it fails then nil will be returned.
  • bool. If value is true, then the function will return 1 otherwise 0.
  • int64. The function returns the value without changes.

If value is another type or parsing failed nil is always returned.

The value is either a path expression to a telemetry field to retrieve or a literal.

Examples:

  • Int(attributes["http.status_code"])

  • Int("2.0")

IsBool

IsBool(value)

The IsBool Converter evaluates whether the given value is a boolean or not.

Specifically, it will return true if the provided value is one of the following:

  1. A Go's native bool type.
  2. A pcommon.ValueTypeBool.

Otherwise, it will return false.

Examples:

  • IsBool(false)

  • IsBool(pcommon.NewValueBool(false))

  • IsBool(42)

  • IsBool(attributes["any key"])

IsDouble

IsDouble(value)

The IsDouble Converter returns true if the given value is a double.

The value is either a path expression to a telemetry field to retrieve, or a literal.

If value is a float64 or a pcommon.ValueTypeDouble then returns true, otherwise returns false.

Examples:

  • IsDouble(body)

  • IsDouble(attributes["maybe a double"])

IsInt

IsInt(value)

The IsInt Converter returns true if the given value is a int.

The value is either a path expression to a telemetry field to retrieve, or a literal.

If value is a int64 or a pcommon.ValueTypeInt then returns true, otherwise returns false.

Examples:

  • IsInt(body)

  • IsInt(attributes["maybe a int"])

IsRootSpan

IsRootSpan()

The IsRootSpan Converter returns true if the span in the corresponding context is root, which means its parent_span_id is equal to hexadecimal representation of zero.

This function is supported with OTTL span context. In any other context it is not supported.

The function returns false in all other scenarios, including parent_span_id == "" or parent_span_id == nil.

Examples:

  • IsRootSpan()

  • set(attributes["isRoot"], "true") where IsRootSpan()

IsMap

IsMap(value)

The IsMap Converter returns true if the given value is a map.

The value is either a path expression to a telemetry field to retrieve or a literal.

If value is a map[string]any or a pcommon.ValueTypeMap then returns true, otherwise returns false.

Examples:

  • IsMap(body)

  • IsMap(attributes["maybe a map"])

IsMatch

IsMatch(target, pattern)

The IsMatch Converter returns true if the target matches the regex pattern.

target is either a path expression to a telemetry field to retrieve or a literal string. pattern is a regexp pattern. The matching semantics are identical to regexp.MatchString.

The function matches the target against the pattern, returning true if the match is successful and false otherwise. If target is not a string, it will be converted to one:

  • booleans, ints and floats will be converted using strconv
  • byte slices will be encoded using base64
  • OTLP Maps and Slices will be JSON encoded
  • other OTLP Values will use their canonical string representation via AsString

If target is nil, false is always returned.

Examples:

  • IsMatch(attributes["http.path"], "foo")

  • IsMatch("string", ".*ring")

IsList

IsList(value)

The IsList Converter returns true if the given value is a list.

The value is either a path expression to a telemetry field to retrieve or a literal.

If value is a list, pcommon.ValueTypeSlice. pcommon.Slice, or any other list type, then returns true, otherwise returns false.

Examples:

  • IsList(body)

  • IsList(attributes["maybe a slice"])

IsString

IsString(value)

The IsString Converter returns true if the given value is a string.

The value is either a path expression to a telemetry field to retrieve or a literal.

If value is a string or a pcommon.ValueTypeStr then returns true, otherwise returns false.

Examples:

  • IsString(body)

  • IsString(attributes["maybe a string"])

Len

Len(target)

The Len Converter returns the int64 length of the target string or slice.

target is either a string, slice, map, pcommon.Slice, pcommon.Map, or pcommon.Value with type pcommon.ValueTypeStr, pcommon.ValueTypeSlice, or pcommon.ValueTypeMap.

If the target is not an acceptable type, the Len Converter will return an error.

Examples:

  • Len(body)

Log

Log(value)

The Log Converter returns a float64 that is the logarithm of the target.

target is either a path expression to a telemetry field to retrieve or a literal.

The function take the logarithm of the target, returning an error if the target is less than or equal to zero.

If target is not a float64, it will be converted to one:

  • int64s are converted to float64s
  • strings are converted using strconv
  • booleans are converted using 1 for true and 0 for false. This means passing false to the function will cause an error.
  • int, float, string, and bool OTLP Values are converted following the above rules depending on their type. Other types cause an error.

If target is nil an error is returned.

Examples:

  • Log(attributes["duration_ms"])

  • Int(Log(attributes["duration_ms"])

MD5

MD5(value)

The MD5 Converter converts the value to a md5 hash/digest.

The returned type is string.

value is either a path expression to a string telemetry field or a literal string. If value is another type an error is returned.

If an error occurs during hashing it will be returned.

Examples:

  • MD5(attributes["device.name"])

  • MD5("name")

Note: According to the National Institute of Standards and Technology (NIST), MD5 is no longer a recommended hash function. It should be avoided except when required for compatibility. New uses should prefer a SHA-2 family function (e.g. SHA-256, SHA-512) whenever possible.

Microseconds

Microseconds(value)

The Microseconds Converter returns the duration as an integer millisecond count.

value is a time.Duration. If value is another type an error is returned.

The returned type is int64.

Examples:

  • Microseconds(Duration("1h"))

Milliseconds

Milliseconds(value)

The Milliseconds Converter returns the duration as an integer millisecond count.

value is a time.Duration. If value is another type an error is returned.

The returned type is int64.

Examples:

  • Milliseconds(Duration("1h"))

Minute

Minute(value)

The Minute Converter returns the minute component from the specified time using the Go stdlib time.Minute function.

value is a time.Time. If value is another type, an error is returned.

The returned type is int64.

Examples:

  • Minute(Now())

Minutes

Minutes(value)

The Minutes Converter returns the duration as a floating point number of minutes.

value is a time.Duration. If value is another type an error is returned.

The returned type is float64.

Examples:

  • Minutes(Duration("1h"))

Month

Month(value)

The Month Converter returns the month component from the specified time using the Go stdlib time.Month function.

value is a time.Time. If value is another type, an error is returned.

The returned type is int64.

Examples:

  • Month(Now())

Nanoseconds

Nanoseconds(value)

The Nanoseconds Converter returns the duration as an integer nanosecond count.

value is a time.Duration. If value is another type an error is returned.

The returned type is int64.

Examples:

  • Nanoseconds(Duration("1h"))

Now

Now()

The Now function returns the current time as represented by time.Now() in Go.

The returned type is time.Time.

Examples:

  • UnixSeconds(Now())
  • set(start_time, Now())

ParseCSV

ParseCSV(target, headers, Optional[delimiter], Optional[headerDelimiter], Optional[mode])

The ParseCSV Converter returns a pcommon.Map struct that contains the result of parsing the target string as CSV. The resultant map is structured such that it is a mapping of field name -> field value.

target is a Getter that returns a string. This string should be a CSV row. if target is not a properly formatted CSV row, or if the number of fields in target does not match the number of fields in headers, ParseCSV will return an error. Leading and trailing newlines in target will be stripped. Newlines elswhere in target are not treated as row delimiters during parsing, and will be treated as though they are part of the field that are placed in.

headers is a Getter that returns a string. This string should be a CSV header, specifying the names of the CSV fields.

delimiter is an optional string parameter that specifies the delimiter used to split target into fields. By default, it is set to ,.

headerDelimiter is an optional string parameter that specified the delimiter used to split headers into fields. By default, it is set to the value of delimiter.

mode is an optional string paramater that specifies the parsing mode. Valid values are strict, lazyQuotes, and ignoreQuotes. By default, it is set to strict.

  • The strict mode provides typical CSV parsing.
  • The lazyQotes mode provides a relaxed version of CSV parsing where a quote may appear in the middle of a unquoted field.
  • The ignoreQuotes mode completely ignores any quoting rules for CSV and just splits the row on the delimiter.

Examples:

  • ParseCSV("999-999-9999,Joe Smith,joe.smith@example.com", "phone,name,email")

  • ParseCSV(body, "phone|name|email", delimiter="|")

  • ParseCSV(attributes["csv_line"], attributes["csv_headers"], delimiter="|", headerDelimiter=",", mode="lazyQuotes")

  • ParseCSV("\"555-555-5556,Joe Smith\",joe.smith@example.com", "phone,name,email", mode="ignoreQuotes")

ParseJSON

ParseJSON(target)

The ParseJSON Converter returns a pcommon.Map or pcommon.Slice struct that is a result of parsing the target string as JSON

target is a Getter that returns a string. This string should be in json format. If target is not a string, nil, or cannot be parsed as JSON, ParseJSON will return an error.

Unmarshalling is done using jsoniter. Each JSON type is converted into a pdata.Value using the following map:

JSON boolean -> bool
JSON number  -> float64
JSON string  -> string
JSON null    -> nil
JSON arrays  -> pdata.SliceValue
JSON objects -> map[string]any

Examples:

  • ParseJSON("{\"attr\":true}")

  • ParseJSON("[\"attr1\",\"attr2\"]")

  • ParseJSON(attributes["kubernetes"])

  • ParseJSON(body)

ParseKeyValue

ParseKeyValue(target, Optional[delimiter], Optional[pair_delimiter])

The ParseKeyValue Converter returns a pcommon.Map that is a result of parsing the target string for key value pairs.

target is a Getter that returns a string. If the returned string is empty, an error will be returned. delimiter is an optional string that is used to split the key and value in a pair, the default is =. pair_delimiter is an optional string that is used to split key value pairs, the default is a single space ( ).

For example, the following target "k1=v1 k2=v2 k3=v3" will use default delimiters and be parsed into the following map:

{ "k1": "v1", "k2": "v2", "k3": "v3" }

Examples:

  • ParseKeyValue("k1=v1 k2=v2 k3=v3")
  • ParseKeyValue("k1!v1_k2!v2_k3!v3", "!", "_")
  • ParseKeyValue(attributes["pairs"])

ParseSimplifiedXML

ParseSimplifiedXML(target)

The ParseSimplifiedXML Converter returns a pcommon.Map struct that is the result of parsing the target string without preservation of attributes or extraneous text content.

The goal of this Converter is to produce a more user-friendly representation of XML data than the ParseXML Converter. This Converter should be preferred over ParseXML when minor semantic details (e.g. order of elements) are not critically important, when subsequent processing or querying of the result is expected, or when human-readability is a concern.

This Converter disregards certain aspects of XML, specifically attributes and extraneous text content, in order to produce a direct representation of XML data. Users are encouraged to simplify their XML documents prior to using ParseSimplifiedXML.

See other functions which may be useful for preparing XML documents:

  • ConvertAttributesToElementsXML
  • ConvertTextToElementsXML
  • RemoveXML
  • InsertXML
  • GetXML

Formal Definitions

A "Simplified XML" document contains no attributes and no extraneous text content.

An element has "extraneous text content" when it contains both text and element content. e.g.

<foo>
    bar <!-- extraneous text content -->
    <hello>world</hello> <!-- element content -->
</foo>

Parsing logic

  1. Declaration elements, attributes, comments, and extraneous text content are ignored.
  2. Elements which contain a value are converted into key/value pairs. e.g. <foo>bar</foo> becomes "foo": "bar"
  3. Elements which contain child elements are converted into a key/value pair where the value is a map. e.g. <foo> <bar>baz</bar> </foo> becomes "foo": { "bar": "baz" }
  4. Sibling elements that share the same tag will be combined into a slice. e.g. <a> <b>1</b> <c>2</c> <c>3</c> </foo> becomes "a": { "b": "1", "c": [ "2", "3" ] }.
  5. Empty elements are dropped, but they can determine whether a value should be a slice or map. e.g. <a> <b>1</b> <b/> </a> becomes "a": { "b": [ "1" ] } instead of "a": { "b": "1" }

Examples

Parse a Simplified XML document from the body:

<event>
    <id>1</id>
    <user>jane</user>
    <details>
      <time>2021-10-01T12:00:00Z</time>
      <description>Something happened</description>
      <cause>unknown</cause>
    </details>
</event>
{
  "event": {
    "id": 1,
    "user": "jane",
    "details": {
      "time": "2021-10-01T12:00:00Z",
      "description": "Something happened",
      "cause": "unknown"
    }
  }
}

Parse a Simplified XML document with unique child elements:

<x>
  <y>1</y>
  <z>2</z>
</x>
{
  "x": {
    "y": "1",
    "z": "2"
  }
}

Parse a Simplified XML document with multiple elements of the same tag:

<a>
  <b>1</b>
  <b>2</b>
</a>
{
  "a": {
    "b": ["1", "2"]
  }
}

Parse a Simplified XML document with CDATA element:

<a>
  <b>1</b>
  <b><![CDATA[2]]></b>
</a>
{
  "a": {
    "b": ["1", "2"]
  }
}

ParseXML

ParseXML(target)

The ParseXML Converter returns a pcommon.Map struct that is the result of parsing the target string as an XML document.

target is a Getter that returns a string. This string should be in XML format. If target is not a string, nil, or cannot be parsed as XML, ParseXML will return an error.

Unmarshalling XML is done using the following rules:

  1. All character data for an XML element is trimmed, joined, and placed into the content field.
  2. The tag for an XML element is trimmed, and placed into the tag field.
  3. The attributes for an XML element is placed as a pcommon.Map into the attribute field.
  4. Processing instructions, directives, and comments are ignored and not represented in the resultant map.
  5. All child elements are parsed as above, and placed in a pcommon.Slice, which is then placed into the children field.

For example, the following XML document:

<?xml version="1.0" encoding="UTF-8" ?>
<Log>
  <User>
    <ID>00001</ID>
    <Name type="first">Joe</Name>
    <Email>joe.smith@example.com</Email>
  </User>
  <Text>User fired alert A</Text>
</Log>

will be parsed as:

{
  "tag": "Log",
  "children": [
    {
      "tag": "User",
      "children": [
        {
          "tag": "ID",
          "content": "00001"
        },
        {
          "tag": "Name",
          "content": "Joe",
          "attributes": {
            "type": "first"
          }
        },
        {
          "tag": "Email",
          "content": "joe.smith@example.com"
        }
      ]
    },
    {
      "tag": "Text",
      "content": "User fired alert A"
    }
  ]
}

Examples:

  • ParseXML(body)

  • ParseXML(attributes["xml"])

  • ParseXML("<HostInfo hostname=\"example.com\" zone=\"east-1\" cloudprovider=\"aws\" />")

RemoveXML

RemoveXML(target, xpath)

The RemoveXML Converter returns an edited version of an XML string with selected elements removed.

target is a Getter that returns a string. This string should be in XML format. If target is not a string, nil, or is not valid xml, RemoveXML will return an error.

xpath is a string that specifies an XPath expression that selects one or more elements to remove from the XML document.

For example, the XPath /Log/Record[./Name/@type="archive"] applied to the following XML document:

<?xml version="1.0" encoding="UTF-8" ?>
<Log>
  <Record>
    <ID>00001</ID>
    <Name type="archive"></Name>
    <Data>Some data</Data>
  </Record>
  <Record>
    <ID>00002</ID>
    <Name type="user"></Name>
    <Data>Some data</Data>
  </Record>
</Log>

will return:

<?xml version="1.0" encoding="UTF-8" ?>
<Log>
  <Record>
    <ID>00002</ID>
    <Name type="user"></Name>
    <Data>Some data</Data>
  </Record>
</Log>

Examples:

Delete the attribute "foo" from the elements with tag "a"

  • RemoveXML(body, "/a/@foo")

Delete all elements with tag "b" that are children of elements with tag "a"

  • RemoveXML(body, "/a/b")

Delete all elements with tag "b" that are children of elements with tag "a" and have the attribute "foo" with value "bar"

  • RemoveXML(body, "/a/b[@foo='bar']")

Delete all comments

  • RemoveXML(body, "//comment()")

Delete text from nodes that contain the word "sensitive"

  • RemoveXML(body, "//*[contains(text(), 'sensitive')]")

Seconds

Seconds(value)

The Seconds Converter returns the duration as a floating point number of seconds.

value is a time.Duration. If value is another type an error is returned.

The returned type is float64.

Examples:

  • Seconds(Duration("1h"))

SHA1

SHA1(value)

The SHA1 Converter converts the value to a sha1 hash/digest.

The returned type is string.

value is either a path expression to a string telemetry field or a literal string. If value is another type an error is returned.

If an error occurs during hashing it will be returned.

Examples:

  • SHA1(attributes["device.name"])

  • SHA1("name")

Note: According to the National Institute of Standards and Technology (NIST), SHA1 is no longer a recommended hash function. It should be avoided except when required for compatibility. New uses should prefer a SHA-2 family function (such as SHA-256 or SHA-512) whenever possible.

SHA256

SHA256(value)

The SHA256 Converter converts the value to a sha256 hash/digest.

The returned type is string.

value is either a path expression to a string telemetry field or a literal string. If value is another type an error is returned.

If an error occurs during hashing it will be returned.

Examples:

  • SHA256(attributes["device.name"])

  • SHA256("name")

SHA512

SHA512(input)

The SHA512 converter calculates sha512 hash value/digest of the input.

The returned type is string.

input is either a path expression to a string telemetry field or a literal string. If input is another type, converter raises an error. If an error occurs during hashing, the error will be returned.

Examples:

  • SHA512(attributes["device.name"])

  • SHA512("name")

Sort

Sort(target, Optional[order])

The Sort Converter sorts the target array in either ascending or descending order.

target is an array or pcommon.Slice typed field containing the elements to be sorted.

order is a string specifying the sort order. Must be either asc or desc. The default value is asc.

The Sort Converter preserves the data type of the original elements while sorting. The behavior varies based on the types of elements in the target slice:

Element Types Sorting Behavior Return Value
Integers Sorts as integers Sorted array of integers
Doubles Sorts as doubles Sorted array of doubles
Integers and doubles Converts all to doubles, then sorts Sorted array of integers and doubles
Strings Sorts as strings Sorted array of strings
Booleans Converts all to strings, then sorts Sorted array of booleans
Mix of integers, doubles, booleans, and strings Converts all to strings, then sorts Sorted array of mixed types
Any other types N/A Returns an error

Examples:

  • Sort(attributes["device.tags"])
  • Sort(attributes["device.tags"], "desc")

SpanID

SpanID(bytes)

The SpanID Converter returns a pdata.SpanID struct from the given byte slice.

bytes is a byte slice of exactly 8 bytes.

Examples:

  • SpanID(0x0000000000000000)

Split

Split(target, delimiter)

The Split Converter separates a string by the delimiter, and returns an array of substrings.

target is a string. delimiter is a string.

If the target is not a string or does not exist, the Split Converter will return an error.

Examples:

  • Split("A|B|C", "|")

String

String(value)

The String Converter converts the value to string type.

The returned type is string.

  • string. The function returns the value without changes.
  • []byte. The function returns the value as a string encoded in hexadecimal.
  • map. The function returns the value as a key-value-pair of type string.
  • slice. The function returns the value as a list formatted string.
  • pcommon.Value. The function returns the value as a string type.

If value is of another type it gets marshalled to string type. If value is empty, or parsing failed, nil is always returned.

The value is either a path expression to a telemetry field to retrieve, or a literal.

Examples:

  • String("test")
  • String(attributes["http.method"])
  • String(span_id)
  • String([1,2,3])
  • String(false)

Substring

Substring(target, start, length)

The Substring Converter returns a substring from the given start index to the specified length.

target is a string. start and length are int64.

If target is not a string or is nil, an error is returned. If the start/length exceed the length of the target string, an error is returned.

Examples:

  • Substring("123456789", 0, 3)

Time

Time(target, format, Optional[location], Optional[locale])

The Time Converter takes a string representation of a time and converts it to a Golang time.Time.

target is a string. format is a string, location is an optional string, locale is an optional string.

If either target or format are nil, an error is returned. The parser used is the parser at internal/coreinternal/parser. If the target and format do not follow the parsing rules used by this parser, an error is returned.

format denotes a textual representation of the time value formatted according to ctime-like format string. It follows standard Go Layout formatting with few additional substitutes:

substitution description examples
%Y Year as a zero-padded number 0001, 0002, ..., 2019, 2020, ..., 9999
%y Year, last two digits as a zero-padded number 01, ..., 99
%m Month as a zero-padded number 01, 02, ..., 12
%o Month as a space-padded number 1, 2, ..., 12
%q Month as an unpadded number 1,2,...,12
%b, %h Abbreviated month name Jan, Feb, ...
%B Full month name January, February, ...
%d Day of the month as a zero-padded number 01, 02, ..., 31
%e Day of the month as a space-padded number 1, 2, ..., 31
%g Day of the month as a unpadded number 1,2,...,31
%a Abbreviated weekday name Sun, Mon, ...
%A Full weekday name Sunday, Monday, ...
%H Hour (24-hour clock) as a zero-padded number 00, ..., 24
%I Hour (12-hour clock) as a zero-padded number 00, ..., 12
%l Hour 12-hour clock 0, ..., 24
%p Locale’s equivalent of either AM or PM AM, PM
%P Locale’s equivalent of either am or pm am, pm
%M Minute as a zero-padded number 00, 01, ..., 59
%S Second as a zero-padded number 00, 01, ..., 59
%L Millisecond as a zero-padded number 000, 001, ..., 999
%f Microsecond as a zero-padded number 000000, ..., 999999
%s Nanosecond as a zero-padded number 00000000, ..., 99999999
%z UTC offset in the form ±HHMM[SS[.ffffff]] or empty +0000, -0400
%Z Timezone name or abbreviation or empty UTC, EST, CST
%i Timezone as +/-HH -07
%j Timezone as +/-HH:MM -07:00
%k Timezone as +/-HH:MM:SS -07:00:00
%w Timezone as +/-HHMMSS -070000
%D, %x Short MM/DD/YYYY date, equivalent to %m/%d/%y 01/21/2031
%F Short YYYY-MM-DD date, equivalent to %Y-%m-%d 2031-01-21
%T,%X ISO 8601 time format (HH:MM:SS), equivalent to %H:%M:%S 02:55:02
%r 12-hour clock time 02:55:02 pm
%R 24-hour HH:MM time, equivalent to %H:%M 13:55
%n New-line character ('\n')
%t Horizontal-tab character ('\t')
%% A % sign
%c Date and time representation Mon Jan 02 15:04:05 2006

location specifies a default time zone canonical ID to be used for date parsing in case it is not part of format.

When loading location, this function will look for the IANA Time Zone database in the following locations in order:

  • a directory or uncompressed zip file named by the ZONEINFO environment variable
  • on a Unix system, the system standard installation location
  • $GOROOT/lib/time/zoneinfo.zip
  • the time/tzdata package, if it was imported.

When building a Collector binary, importing time/tzdata in any Go source file will bundle the database into the binary, which guarantees the lookups will work regardless of the setup on the host setup. Note this will add roughly 500kB to binary size.

Examples:

  • Time("02/04/2023", "%m/%d/%Y")
  • Time("Feb 15, 2023", "%b %d, %Y")
  • Time("2023-05-26 12:34:56 HST", "%Y-%m-%d %H:%M:%S %Z")
  • Time("1986-10-01T00:17:33 MST", "%Y-%m-%dT%H:%M:%S %Z")
  • Time("2012-11-01T22:08:41+0000 EST", "%Y-%m-%dT%H:%M:%S%z %Z")
  • Time("2023-05-26 12:34:56", "%Y-%m-%d %H:%M:%S", "America/New_York")

locale specifies the input language of the target value. It is used to interpret timestamp values written in a specific language, ensuring that the function can correctly parse the localized month names, day names, and periods of the day based on the provided language.

The value must be a well-formed BCP 47 language tag, and a known CLDR v45 locale. If not supplied, English (en) is used.

Examples:

  • Time("mercoledì set 4 2024", "%A %h %e %Y", "", "it")
  • Time("Febrero 25 lunes, 2002, 02:03:04 p.m.", "%B %d %A, %Y, %r", "America/New_York", "es-ES")

ToKeyValueString

ToKeyValueString(target, Optional[delimiter], Optional[pair_delimiter], Optional[sort_output])

The ToKeyValueString Converter takes a pcommon.Map and converts it to a string of key value pairs.

  • target is a Getter that returns a pcommon.Map.
  • delimiter is an optional string that is used to join keys and values, the default is =.
  • pair_delimiter is an optional string that is used to join key value pairs, the default is a single space ( ).
  • sort_output is an optional bool that is used to deterministically sort the keys of the output string. It should only be used if the output is required to be in the same order each time, as it introduces some performance overhead.

For example, the following map {"k1":"v1","k2":"v2","k3":"v3"} will use default delimiters and be converted into the following string:

`k1=v1 k2=v2 k3=v3`

Note: Any nested arrays or maps will be represented as a JSON string. It is recommended to flatten target before using this function.

For example, {"k1":"v1","k2":{"k3":"v3","k4":["v4","v5"]}} will be converted to:

`k1=v1 k2={\"k3\":\"v3\",\"k4\":[\"v4\",\"v5\"]}`

Note: If any keys or values contain either delimiter, they will be double quoted. If any double quotes are present in the quoted value, they will be escaped.

For example, {"k1":"v1","k2":"v=2","k3"="\"v=3\""} will be converted to:

`k1=v1 k2="v=2" k3="\"v=3\""`

Examples:

  • ToKeyValueString(body)
  • ToKeyValueString(body, ":", ",", true)

TraceID

TraceID(bytes)

The TraceID Converter returns a pdata.TraceID struct from the given byte slice.

bytes is a byte slice of exactly 16 bytes.

Examples:

  • TraceID(0x00000000000000000000000000000000)

TruncateTime

TruncateTime(time, duration)

The TruncateTime Converter returns the given time rounded down to a multiple of the given duration. The Converter uses the time.Truncate function.

time is a time.Time. duration is a time.Duration. If time is not a time.Time or if duration is not a time.Duration, an error will be returned.

While some common paths can return a time.Time object, you will most like need to use the Duration Converter to create a time.Duration.

Examples:

  • TruncateTime(start_time, Duration("1s"))

Unix

Unix(seconds, Optional[nanoseconds])

The Unix Converter returns an epoch timestamp as a Unix time. Similar to Golang's Unix function.

seconds is int64. If seconds is another type an error is returned. nanoseconds is int64. It is optional and its default value is 0. If nanoseconds is another type an error is returned.

The returned type is time.Time.

Examples:

  • Unix(1672527600)

UnixMicro

UnixMicro(value)

The UnixMicro Converter returns the time as a Unix time, the number of microseconds elapsed since January 1, 1970 UTC.

value is a time.Time. If value is another type an error is returned.

The returned type is int64.

Examples:

  • UnixMicro(Time("02/04/2023", "%m/%d/%Y"))

UnixMilli

UnixMilli(value)

The UnixMilli Converter returns the time as a Unix time, the number of milliseconds elapsed since January 1, 1970 UTC.

value is a time.Time. If value is another type an error is returned.

The returned type is int64.

Examples:

  • UnixMilli(Time("02/04/2023", "%m/%d/%Y"))

UnixNano

UnixNano(value)

The UnixNano Converter returns the time as a Unix time, the number of nanoseconds elapsed since January 1, 1970 UTC.

value is a time.Time. If value is another type an error is returned.

The returned type is int64.

Examples:

  • UnixNano(Time("02/04/2023", "%m/%d/%Y"))

UnixSeconds

UnixSeconds(value)

The UnixSeconds Converter returns the time as a Unix time, the number of seconds elapsed since January 1, 1970 UTC.

value is a time.Time. If value is another type an error is returned.

The returned type is int64.

Examples:

  • UnixSeconds(Time("02/04/2023", "%m/%d/%Y"))

UserAgent

UserAgent(value)

The UserAgent Converter parses the string argument trying to match it against well-known user-agent strings.

value is a string or a path to a string. If value is not a string an error is returned.

The results of the parsing are returned as a map containing user_agent.name, user_agent.version and user_agent.original as defined in semconv v1.25.0.

Parsing is done using the uap-go package. The specific formats it recognizes can be found here.

Examples:

  • UserAgent("curl/7.81.0") 
    "user_agent.name": "curl"
"user_agent.version": "7.81.0"
"user_agent.original": "curl/7.81.0"
  • Mozilla/5.0 (X11; Linux x86_64; rv:126.0) Gecko/20100101 Firefox/126.0 
    "user_agent.name": "Firefox"
"user_agent.version": "126.0"
"user_agent.original": "Mozilla/5.0 (X11; Linux x86_64; rv:126.0) Gecko/20100101 Firefox/126.0"

URL

URL(url_string)

Parses a Uniform Resource Locator (URL) string and extracts its components as an object. This URL object includes properties for the URL’s domain, path, fragment, port, query, scheme, user info, username, and password.

original, domain, scheme, and path are always present. Other properties are present only if they have corresponding values.

url_string is a string.

  • URL("http://www.example.com")

results in

  "url.original": "http://www.example.com",
  "url.scheme":   "http",
  "url.domain":   "www.example.com",
  "url.path":     "",
  • URL("http://myusername:mypassword@www.example.com:80/foo.gif?key1=val1&key2=val2#fragment")

results in

  "url.path":      "/foo.gif",
  "url.fragment":  "fragment",
  "url.extension": "gif",
  "url.password":  "mypassword",
  "url.original":  "http://myusername:mypassword@www.example.com:80/foo.gif?key1=val1&key2=val2#fragment",
  "url.scheme":    "http",
  "url.port":      80,
  "url.user_info": "myusername:mypassword",
  "url.domain":    "www.example.com",
  "url.query":     "key1=val1&key2=val2",
  "url.username":  "myusername",

UUID

UUID()

The UUID function generates a v4 uuid string.

Year

Year(value)

The Year Converter returns the year component from the specified time using the Go stdlib time.Year function.

value is a time.Time. If value is another type, an error is returned.

The returned type is int64.

Examples:

  • Year(Now())

Function syntax

Functions should be named and formatted according to the following standards.

  • Function names MUST start with a verb unless it is a Factory that creates a new type.
  • Converters MUST be UpperCamelCase.
  • Function names that contain multiple words MUST separate those words with _.
  • Functions that interact with multiple items MUST have plurality in the name. Ex: truncate_all, keep_keys, replace_all_matches.
  • Functions that interact with a single item MUST NOT have plurality in the name. If a function would interact with multiple items due to a condition, like where, it is still considered singular. Ex: set, delete, replace_match.
  • Functions that change a specific target MUST set the target as the first parameter.

Adding New Editors/Converters

Before raising a PR with a new Editor or Converter, raise an issue to verify its acceptance. While acceptance is strongly specific to a specific use case, consider these guidelines for early assessment.

Your proposal likely will be accepted if:

  • The proposed functionality is missing,
  • The proposed solution significantly improves user experience and readability for very common use cases,
  • The proposed solution is more performant in cases where it is possible to achieve the same result with existing options.

It will be up for discussion if your proposal solves an issue that can be achieved in another way but does not improve user experience or performance.

Your proposal likely won't be accepted if:

  • User experience is worse and assumes a highly technical user,
  • The performance of your proposal very negatively affects the processing pipeline.

As with code, OTTL aims for readability first. This means:

  • Using short, meaningful, and descriptive names,
  • Ensuring naming consistency across Editors and Converters,
  • Avoiding deep nesting to achieve desired transformations,
  • Ensuring Editors and Converters have a single responsibility.