use metadata to generate status table

This is a proposed first step to remove needing to generate a table for each component separately. As part of this change I propose we also use the metadata to auto-generate the code to return the component status.

Link issue: open-telemetry#19175

Signed-off-by: Alex Boten <aboten@lightstep.com>

.chloggen/codeboten_doc-status.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: mdatagen
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: use metadata to generate status table
+
+# One or more tracking issues related to the change
+issues: [19175]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

cmd/mdatagen/loader.go

@@ -211,6 +211,8 @@ func (attr *attribute) Unmarshal(parser *confmap.Conf) error {
 type metadata struct {
 	// Name of the component.
 	Name string `mapstructure:"name"`
+	// Status information for the component.
+	Status Status `mapstructure:"status"`
 	// SemConvVersion is a version number of OpenTelemetry semantic conventions applied to the scraped metrics.
 	SemConvVersion string `mapstructure:"sem_conv_version"`
 	// ResourceAttributes that can be emitted by the component.

cmd/mdatagen/main.go

@@ -57,6 +57,12 @@ func run(ymlPath string) error {
 		filepath.Join(codeDir, "generated_metrics.go"), md); err != nil {
 		return err
 	}
+	if len(md.Status.Stability) > 0 {
+		if err = generateFile(filepath.Join(tmplDir, "status.go.tmpl"),
+			filepath.Join(codeDir, "generated_status.go"), md); err != nil {
+			return err
+		}
+	}
 	if err = generateFile(filepath.Join(tmplDir, "testdata", "config.yaml.tmpl"),
 		filepath.Join(codeDir, "testdata", "config.yaml"), md); err != nil {
 		return err
@@ -99,6 +105,36 @@ func generateFile(tmplFile string, outputFile string, md metadata) error {
 				},
 				"stringsJoin": strings.Join,
 				"inc":         func(i int) int { return i + 1 },
+				"stability": func(in string) string {
+					switch in {
+					case "alpha":
+						return "Alpha"
+					case "beta":
+						return "Beta"
+					case "unmaintained":
+						return "Unmaintained"
+					case "deprecated":
+						return "Deprecated"
+					case "development":
+						return "Development"
+					case "stable":
+						return "Stable"
+					}
+					return "Undefined"
+				},
+				"distroJoin": func(d []Distribution, sep string) string {
+					if len(d) == 1 {
+						return d[0].Name
+					}
+					output := ""
+					for idx, distro := range d {
+						if idx > 0 {
+							output += sep
+						}
+						output += distro.Name
+					}
+					return output
+				},
 				// ParseFS delegates the parsing of the files to `Glob`
 				// which uses the `\` as a special character.
 				// Meaning on windows based machines, the `\` needs to be replaced

cmd/mdatagen/statusdata.go

@@ -0,0 +1,27 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//       http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+type Distribution struct {
+	Name string `mapstructure:"name"`
+	URL  string `mapstructure:"url"`
+}
+
+type Status struct {
+	Stability     string         `mapstructure:"stability"`
+	Pipelines     []string       `mapstructure:"pipelines"`
+	Distributions []Distribution `mapstructure:"distributions"`
+	Type          string         `mapstructure:"type"`
+}

cmd/mdatagen/templates/documentation.md.tmpl

@@ -37,7 +37,13 @@
 [comment]: <> (Code generated by mdatagen. DO NOT EDIT.)
 
 # {{ .Name }}
-
+{{if ne .Status.Stability "" }}
+| Status                   |           |
+| ------------------------ |-----------|
+| Stability                | [{{ .Status.Stability }}]   |
+| Supported pipeline types | {{range .Status.Pipelines }}{{.}},{{end}}   |
+| Distributions            | [{{ distroJoin .Status.Distributions "], [" }}] |
+{{ end }}
 ## Default Metrics
 
 The following metrics are emitted by default. Each of them can be disabled by applying the following configuration:
@@ -91,3 +97,9 @@ metrics:
 {{- end }}
 
 {{- end }}
+{{if ne .Status.Stability "" }}
+[{{ .Status.Stability }}]: https://github.com/open-telemetry/opentelemetry-collector#{{ .Status.Stability }}
+{{range .Status.Distributions }}
+[{{.Name}}]: {{.URL}}
+{{end}}
+{{- end -}}

cmd/mdatagen/templates/status.go.tmpl

@@ -0,0 +1,9 @@
+// Code generated by mdatagen. DO NOT EDIT.
+
+package {{ .Package }}
+
+import (
+    "go.opentelemetry.io/collector/component"
+)
+
+const Stability = component.StabilityLevel{{ stability .Status.Stability }}

receiver/haproxyreceiver/README.md

@@ -1,10 +1,6 @@
 # HAProxy Receiver
 
-| Status                   |           |
-| ------------------------ |-----------|
-| Stability                | [alpha]   |
-| Supported pipeline types | metrics   |
-| Distributions            | [contrib] |
+Component [status](./documentation.md#haproxyreceiver).
 
 The HAProxy receiver generates metrics by polling periodically the HAProxy process through a dedicated socket or HTTP URL.
 
@@ -50,6 +46,3 @@ receivers:
       haproxy.requests:
         enabled: true
 ```
-
-[alpha]: https://github.com/open-telemetry/opentelemetry-collector#alpha
-

receiver/haproxyreceiver/documentation.md

@@ -2,6 +2,12 @@
 
 # haproxyreceiver
 
+| Status                   |           |
+| ------------------------ |-----------|
+| Stability                | [alpha]   |
+| Supported pipeline types | metrics,   |
+| Distributions            | [contrib] |
+
 ## Default Metrics
 
 The following metrics are emitted by default. Each of them can be disabled by applying the following configuration:
@@ -249,3 +255,7 @@ Cumulative number of sessions. Corresponds to HAProxy's `stot` metric.
 | haproxy.url | The path to the HAProxy socket or HTTP URL. | Any Str | true |
 | proxy_name | Proxy name | Any Str | false |
 | service_name | Service name (FRONTEND for frontend, BACKEND for backend, any name for server/listener) | Any Str | false |
+
+[alpha]: https://github.com/open-telemetry/opentelemetry-collector#alpha
+
+[contrib]: https://github.com/open-telemetry/opentelemetry-collector-releases/tree/main/distributions/otelcol-contrib

receiver/haproxyreceiver/factory.go

@@ -27,16 +27,15 @@ import (
 )
 
 const (
-	typeStr   = "haproxy"
-	stability = component.StabilityLevelAlpha
+	typeStr = "haproxy"
 )
 
 // NewFactory creates a new HAProxy receiver factory.
 func NewFactory() receiver.Factory {
 	return receiver.NewFactory(
 		typeStr,
 		newDefaultConfig,
-		receiver.WithMetrics(newReceiver, stability))
+		receiver.WithMetrics(newReceiver, metadata.Stability))
 }
 
 func newDefaultConfig() component.Config {

receiver/haproxyreceiver/metadata.yaml

@@ -1,5 +1,13 @@
 name: haproxyreceiver
 
+status:
+  type: receiver
+  stability: alpha
+  pipelines: [metrics]
+  distributions:
+    - name: contrib
+      url: https://github.com/open-telemetry/opentelemetry-collector-releases/tree/main/distributions/otelcol-contrib
+
 resource_attributes:
   haproxy.url:
     description: The path to the HAProxy socket or HTTP URL.