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GitHub

Similar to the Source Control Management (SCM) integration plugin, the GitHub integration plugin for Soundcheck provides out-of-box integration with GitHub by leveraging Backstage's GitHub integration to implement extraction and collection of facts from GitHub repositories.

The purpose of the GitHub integration plugin is to provide GitHub-specific fact collection (like branch protections), while the SCM integration plugin provides the collection of facts based on repository content.

The GitHub integration plugin supports the extraction of the following facts:

Prerequisites​

Configure GitHub integration in Backstage​

Integrations are configured at the root level of app-config.yaml. Here's an example configuration for GitHub:

integrations:
  github:
    - host: github.com
      token: ${GITHUB_TOKEN}

Consult the Backstage GitHub integration instructions for full configuration details.

Add the GitHubFactCollector to Soundcheck​

GitHub integration for Soundcheck is not installed by default. It must be manually installed and configured for the GitHub Fact Collector to work.

First, add the @spotify/backstage-plugin-soundcheck-backend-module-github package:

yarn workspace backend add @spotify/backstage-plugin-soundcheck-backend-module-github

Legacy Backend​

If you are still using the legacy backend, in packages/backend/src/plugins/soundcheck.ts, add the GitHubFactCollector:

  import { SoundcheckBuilder } from '@spotify/backstage-plugin-soundcheck-backend';
  import { Router } from 'express';
  import { PluginEnvironment } from '../types';
+ import { GithubFactCollector } from '@spotify/backstage-plugin-soundcheck-backend-module-github';

  export default async function createPlugin(
    env: PluginEnvironment,
  ): Promise<Router> {
    return SoundcheckBuilder.create({ ...env })
+     .addFactCollectors(
+       GithubFactCollector.create(env.config, env.logger, env.cache),
+     )
      .build();
  }

New Backend System​

If you are using the New Backend System, you can just add the following:

packages/backend/src/index.ts
const backend = createBackend();

backend.add(import('@spotify/backstage-plugin-soundcheck-backend'));
backend.add(
  import('@spotify/backstage-plugin-soundcheck-backend-module-github'),
);
// ...

backend.start();

Entity configuration​

To be able to determine the repository to use the GitHub integration will use the value from the backstage.io/source-location annotation. In many cases this will be set for you but if it is not you will need to add it to your catalog-info.yaml file, here's a simple example:

metadata:
  annotations:
    backstage.io/source-location: url:https://github.com/my-org/my-service/

Plugin Configuration​

The collection of facts is driven by configuration. To learn more about the configuration, jump to the Defining GitHub Fact Collectors section.

  1. Create a github-facts-collectors.yaml file in the root of your Backstage repository and fill in all your GitHub Fact Collectors. A simple example GitHub Fact Collector is listed below.

    ---
    frequency:
      cron: '0 * * * *'
    collects:
      - factName: branch_protections
        type: BranchProtections
        branch: master
      - factName: repo_details
        type: RepositoryDetails

    Note: this file will be loaded at runtime along with the rest of your Backstage configuration files. Therefore, make sure that it's available in deployed environments in the same way as your app-config.yaml files are.

  2. Add a soundcheck collectors field to app-config.yaml and reference the newly created github-facts-collectors.yaml

    # app-config.yaml
    soundcheck:
      collectors:
        github:
          $include: ./github-facts-collectors.yaml

Rate Limiting (Optional)​

This fact collector can be rate limited in Soundcheck using the following configuration:

soundcheck:
  job:
    workers:
      github:
        limiter:
          max: 4900
          duration: 3600000

GitHub API has a limit of 5000 requests per hour (15000 for Enterprise). We recommend setting your rate limit to something below this, i.e. in the example above, we set the rate limit to 4900 executions every hour.

This fact collector handles rate limit errors per the recommendation from GitHub. Soundcheck will automatically wait and retry requests that are rate limited.

Defining GitHub Fact Collectors​

This section describes the data shape and semantics of GitHub Fact Collectors.

Overall Shape Of A GitHub Fact Collector​

The following is an example of a descriptor file for a GitHub Fact Collector:

---
frequency:
  cron: '0 * * * *'
initialDelay:
  seconds: 30
filter:
  kind: 'Component'
cache:
  duration:
    hours: 2
collects:
  - factName: branch_protections
    type: BranchProtections
    branch: master
    filter:
      - spec.lifecycle: 'production'
        spec.type: 'website'
    cache: false
  - factName: repo_details
    type: RepositoryDetails
    cache: true

Below are the details for each field.

frequency [optional]​

The frequency at which the collector should be executed. Possible values are either a cron expression { cron: ... } or HumanDuration. This is the default frequency for each extractor.

initialDelay [optional]​

The amount of time that should pass before the first invocation happens. Possible values are either a cron expression { cron: ... } or HumanDuration.

filter [optional]​

A filter specifying which entities to collect the specified facts for. Matches the filter format used by the Catalog API. This is the default filter for each extractor.

cache [optional]​

If the collected facts should be cached, and if so for how long. Possible values are either true or false or a nested { duration: HumanDuration } field. This is the default cache config for each extractor.

collects [required]​

An array describing which facts to collect and how to extract them. See below for details about the overall shape of a fact extractor.

Overall Shape Of A Fact Extractor​

Each extractor supports the fields described below.

factName [required]​

The name of the fact to be extracted.

  • Minimum length of 1
  • Maximum length of 100
  • Alphanumeric with single separator instances of periods, dashes, underscores, or forward slashes

type [required]​

The type of the extractor (e.g. BranchProtections, RepositoryDetails).

frequency [optional]​

The frequency at which the fact extraction should be executed. Possible values are either a cron expression { cron: ... } or HumanDuration. If provided, it overrides the default frequency provided at the top level. If not provided, it defaults to the frequency provided at the top level. If neither extractor's frequency, nor default frequency is provided, the fact will only be collected on demand.

Example:

frequency:
  minutes: 10

branch [optional]​

The branch to extract the fact from. If not provided, defaults to the repository's default branch.

filter [optional]​

A filter specifying which entities to collect the specified facts for. Matches the filter format used by the Catalog API. If provided, it overrides the default filter provided at the top level. If not provided, it defaults to the filter provided at the top level. If neither extractor's filter, nor default filter is provided, the fact will be collected for all entities.

cache [optional]​

If the collected facts should be cached, and if so for how long. Possible values are either true or false or a nested { duration: HumanDuration } field. If provided, it overrides the default cache config provided at the top level. If not provided, it defaults to the cache config provided at the top level. If neither extractor's cache nor default cache config is provided, the fact will not be cached. Example:

cache:
  duration:
    hours: 24

Collecting BranchProtections Fact​

The BranchProtections fact contains information about configured branch protections for a given branch in a GitHub repository.

Shape of A BranchProtections Fact Collector​

The shape of a BranchProtections Fact Collector matches the Overall Shape Of A GitHub Fact Collector (restriction: type: BranchProtections).

The following is an example of the BranchProtections Fact Collector configuration:

collects:
  - factName: branch_protections
    type: BranchProtections
    frequency:
      cron: '0 * * * *'
    branch: master
    filter:
      - spec.lifecycle: 'production'
        spec.type: 'website'
    cache: false

Shape of A BranchProtections Fact​

The shape of a BranchProtections Fact is based on the Fact Schema.

For a description of the data collected regarding branch protection, refer to the GitHub API documentation.

The following is an example of the collected BranchProtections fact:

factRef: github:master/branch_protections
entityRef: component:default/queue-proxy
scope: master
timestamp: 2023-02-24T15:50+00Z
data:
  url: 'https://api.github.com/repos/backstage/backstage/branches/master/protection'
  required_pull_request_reviews:
    url: 'https://api.github.com/repos/backstage/backstage/branches/master/protection/required_pull_request_reviews',
    dismiss_stale_reviews: false
    require_code_owner_reviews: true
    required_approving_review_count: 2
    require_last_push_approval: false
  required_signatures:
    url: 'https://api.github.com/repos/backstage/backstage/branches/master/protection/required_signatures'
    enabled: false
  enforce_admins:
    url: 'https://api.github.com/repos/backstage/backstage/branches/master/protection/enforce_admins'
    enabled: false
  required_linear_history:
    enabled: false
  allow_force_pushes:
    enabled: true
  allow_deletions:
    enabled: true
  block_creations:
    enabled: true
  required_conversation_resolution:
    enabled: false
  lock_branch:
    enabled: false
  allow_fork_syncing:
    enabled: true

Shape of A BranchProtections Fact Check​

The shape of a BranchProtections Fact Check matches the Shape of a Fact Check.

The following is an example of the BranchProtections fact checks:

soundcheck:
  checks:
    - id: requires_code_owner_reviews
      rule:
        factRef: github:master/branch_protections
        path: $.required_pull_request_reviews.require_code_owner_reviews
        operator: equal
        value: true
    - id: requires_at_least_two_approving_reviews
      rule:
        factRef: github:master/branch_protections
        path: $.required_pull_request_reviews.required_approving_review_count
        operator: greaterThanInclusive
        value: 2

The following is an example of the Soundcheck program that utilizes these checks:

- id: demo
  name: Demo
  ownerEntityRef: group:default/owning_group
  description: Demonstration of Soundcheck BranchProtections Fact Extractor
  levels:
    - ordinal: 1
      name: First level
      description: Checks leveraging Soundcheck's GitHub BranchProtections Fact Extractor
      checks:
        - id: requires_code_owner_reviews
          name: Requires code owner reviews
          description: PR requires code owner reviews
        - id: requires_at_least_two_approving_reviews
          name: Requires at least two approving reviews
          description: PR requires at least two approving reviews

Collecting RepositoryDetails Fact​

The RepositoryDetails fact contains information about a GitHub repository.

Shape of A RepositoryDetails Fact Collector​

The shape of a RepositoryDetails Fact Collector matches the Overall Shape Of A GitHub Fact Collector (restriction: type: RepositoryDetails).

The following is an example of the RepositoryDetails Fact Collector configuration:

collects:
  - factName: repo_details
    type: RepositoryDetails
    frequency:
      cron: '0 * * * *'
    filter:
      - spec.lifecycle: 'production'
    cache: true

Shape of A RepositoryDetails Fact​

The shape of a RepositoryDetails Fact is based on the Fact Schema.

For a description of the data collected about repository, refer to the GitHub API documentation.

The following is an example of the collected RepositoryDetails fact:

factRef: github:default/repo_details
entityRef: component:default/queue-proxy
scope: default
timestamp: 2023-02-24T15:50+00Z
data:
  name: backstage
  full_name: backstage/backstage
  private: true
  html_url: 'https://github.com/backstage/backstage'
  description: null
  fork: false
  url: 'https://api.github.com/repos/backstage/backstage'
  homepage: null
  size: 3
  stargazers_count: 0
  watchers_count: 0
  language: null
  has_issues: true
  has_projects: true
  has_downloads: true
  has_wiki: true
  has_pages: false
  has_discussions: false
  forks_count: 0
  mirror_url: null
  archived: false
  disabled: false
  open_issues_count: 0
  license: null
  allow_forking: true
  is_template: false
  web_commit_signoff_required: false
  visibility: 'private'
  forks: 0
  open_issues: 0
  watchers: 0
  default_branch: master
  permissions:
    admin: true
    maintain: true
    push: true
    triage: true
    pull: true
  allow_squash_merge: true
  allow_merge_commit: true
  allow_rebase_merge: true
  allow_auto_merge: false
  delete_branch_on_merge: false
  allow_update_branch: false
  use_squash_pr_title_as_default: false
  squash_merge_commit_message: 'COMMIT_MESSAGES'
  squash_merge_commit_title: 'COMMIT_OR_PR_TITLE'
  merge_commit_message: 'PR_TITLE'
  merge_commit_title: 'MERGE_MESSAGE'
  security_and_analysis:
    secret_scanning:
      status: 'disabled'
    secret_scanning_push_protection:
      status: 'disabled'
  network_count: 0
  subscribers_count: 1

Shape of A RepositoryDetails Fact Check​

The shape of a RepositoryDetails Fact Check matches the Shape of a Fact Check.

The following is an example of the RepositoryDetails fact checks:

soundcheck:
  checks:
    - id: allows_rebase_merge
      rule:
        factRef: github:default/repo_details
        path: $.allow_rebase_merge
        operator: equal
        value: true
    - id: has_less_than_ten_open_issues
      rule:
        factRef: github:default/repo_details
        path: $.open_issues
        operator: lessThan
        value: 10

The following is an example of the Soundcheck program that utilizes these checks:

- id: demo
  name: Demo
  ownerEntityRef: group:default/owning_group
  description: Demonstration of Soundcheck RepositoryDetails Fact Extractor
  levels:
    - ordinal: 1
      name: First level
      description: Checks leveraging Soundcheck's GitHub RepositoryDetails Fact Extractor
      checks:
        - id: allows_rebase_merge
          name: Allows Rebase Merge
          description: Repository allows rebase merge
        - id: has_less_than_ten_open_issues
          name: Has Less Than 10 Open Issues
          description: GitHub Repository Has Less Than 10 Open Issues