Outputs enhancement to require Description and SampleConfig functions

Closes #142

CHANGELOG.md

@@ -5,6 +5,7 @@
 - [#136](https://github.com/influxdb/telegraf/issues/136): Add a -usage flag for printing usage of a single plugin.
 - [#137](https://github.com/influxdb/telegraf/issues/137): Memcached: fix when a value contains a space
 - [#138](https://github.com/influxdb/telegraf/issues/138): MySQL server address tag.
+- [#142](https://github.com/influxdb/telegraf/pull/142): Add Description and SampleConfig funcs to output interface
 
 ### Bugfixes
 - [#128](https://github.com/influxdb/telegraf/issues/128): system_load measurement missing.

config.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/influxdb/telegraf/outputs"
 	"github.com/influxdb/telegraf/plugins"
 	"github.com/naoina/toml"
 	"github.com/naoina/toml/ast"
@@ -326,9 +327,6 @@ type hasDescr interface {
 
 var header = `# Telegraf configuration
 
-# If this file is missing an [agent] section, you must first generate a
-# valid config with 'telegraf -sample-config > telegraf.toml'
-
 # Telegraf is entirely plugin driven. All metrics are gathered from the
 # declared plugins.
 
@@ -348,75 +346,81 @@ var header = `# Telegraf configuration
 # NOTE: The configuration has a few required parameters. They are marked
 # with 'required'. Be sure to edit those to make this configuration work.
 
-# OUTPUTS
-[outputs]
-
-# Configuration for influxdb server to send metrics to
-[outputs.influxdb]
-# The full HTTP endpoint URL for your InfluxDB instance
-url = "http://localhost:8086" # required.
-
-# The target database for metrics. This database must already exist
-database = "telegraf" # required.
-
-# Connection timeout (for the connection with InfluxDB), formatted as a string.
-# Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".
-# If not provided, will default to 0 (no timeout)
-# timeout = "5s"
-
-# username = "telegraf"
-# password = "metricsmetricsmetricsmetrics"
+# Tags can also be specified via a normal map, but only one form at a time:
+[tags]
+	# dc = "us-east-1"
 
-# Set the user agent for the POSTs (can be useful for log differentiation)
-# user_agent = "telegraf"
+# Configuration for telegraf itself
+[agent]
+	# interval = "10s"
+	# debug = false
+	# hostname = "prod3241"
 
-# Tags can also be specified via a normal map, but only one form at a time:
+###############################################################################
+#                                  OUTPUTS                                    #
+###############################################################################
 
-# [tags]
-# dc = "us-east-1" }
+[outputs]
+`
 
-# Configuration for telegraf itself
-# [agent]
-# interval = "10s"
-# debug = false
-# hostname = "prod3241"
+var header2 = `
 
-# PLUGINS
+###############################################################################
+#                                  PLUGINS                                    #
+###############################################################################
 
 `
 
 // PrintSampleConfig prints the sample config!
 func PrintSampleConfig() {
 	fmt.Printf(header)
 
-	var names []string
+	// Print Outputs
+	var onames []string
 
-	for name := range plugins.Plugins {
-		names = append(names, name)
+	for oname := range outputs.Outputs {
+		onames = append(onames, oname)
 	}
+	sort.Strings(onames)
 
-	sort.Strings(names)
+	for _, oname := range onames {
+		creator := outputs.Outputs[oname]
+		output := creator()
 
-	for _, name := range names {
-		creator := plugins.Plugins[name]
+		fmt.Printf("\n# %s\n[outputs.%s]\n", output.Description(), oname)
 
-		plugin := creator()
+		config := output.SampleConfig()
+		if config == "" {
+			fmt.Printf(" 	# no configuration\n\n")
+		} else {
+			fmt.Printf(config)
+		}
+	}
 
-		fmt.Printf("# %s\n[%s]\n", plugin.Description(), name)
+	fmt.Printf(header2)
 
-		var config string
+	// Print Plugins
+	var pnames []string
 
-		config = strings.TrimSpace(plugin.SampleConfig())
+	for pname := range plugins.Plugins {
+		pnames = append(pnames, pname)
+	}
+	sort.Strings(pnames)
+
+	for _, pname := range pnames {
+		creator := plugins.Plugins[pname]
+		plugin := creator()
 
+		fmt.Printf("# %s\n[%s]\n", plugin.Description(), pname)
+
+		config := plugin.SampleConfig()
 		if config == "" {
-			fmt.Printf("  # no configuration\n\n")
+			fmt.Printf("	# no configuration\n\n")
 		} else {
-			fmt.Printf("\n")
 			lines := strings.Split(config, "\n")
 			for _, line := range lines {
 				fmt.Printf("%s\n", line)
 			}
-
 			fmt.Printf("\n")
 		}
 	}

outputs/datadog/datadog.go

@@ -21,6 +21,14 @@ type Datadog struct {
 	client *http.Client
 }
 
+var sampleConfig = `
+	# Datadog API key
+	apikey = "my-secret-key" # required.
+
+	# Connection timeout.
+	# timeout = "5s"
+`
+
 type TimeSeries struct {
 	Series []*Metric `json:"series"`
 }
@@ -91,6 +99,14 @@ func (d *Datadog) Write(bp client.BatchPoints) error {
 	return nil
 }
 
+func (d *Datadog) SampleConfig() string {
+	return sampleConfig
+}
+
+func (d *Datadog) Description() string {
+	return "Configuration for DataDog API to send metrics to."
+}
+
 func (d *Datadog) authenticatedUrl() string {
 	q := url.Values{
 		"api_key": []string{d.Apikey},

outputs/influxdb/influxdb.go

@@ -22,6 +22,25 @@ type InfluxDB struct {
 	conn *client.Client
 }
 
+var sampleConfig = `
+	# The full HTTP endpoint URL for your InfluxDB instance
+	url = "http://localhost:8086" # required.
+
+	# The target database for metrics. This database must already exist
+	database = "telegraf" # required.
+
+	# Connection timeout (for the connection with InfluxDB), formatted as a string.
+	# Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".
+	# If not provided, will default to 0 (no timeout)
+	# timeout = "5s"
+
+	# username = "telegraf"
+	# password = "metricsmetricsmetricsmetrics"
+
+	# Set the user agent for the POSTs (can be useful for log differentiation)
+	# user_agent = "telegraf"
+`
+
 func (i *InfluxDB) Connect() error {
 	u, err := url.Parse(i.URL)
 	if err != nil {
@@ -57,6 +76,14 @@ func (i *InfluxDB) Close() error {
 	return nil
 }
 
+func (i *InfluxDB) SampleConfig() string {
+	return sampleConfig
+}
+
+func (i *InfluxDB) Description() string {
+	return "Configuration for influxdb server to send metrics to"
+}
+
 func (i *InfluxDB) Write(bp client.BatchPoints) error {
 	bp.Database = i.Database
 	if _, err := i.conn.Write(bp); err != nil {

outputs/registry.go

@@ -7,6 +7,8 @@ import (
 type Output interface {
 	Connect() error
 	Close() error
+	Description() string
+	SampleConfig() string
 	Write(client.BatchPoints) error
 }