Deployment–Pull Request Linking#

DevLake links deployments to pull requests by matching cicd_deployment_commits.commit_sha against each PR's merge commit SHA (pull_requests.merge_commit_sha). This join is the foundation of DORA's Change Lead Time metric — specifically the PrDeployTime segment (PR merge → deployment finish).

Data Model#

Three tables participate in the linkage:

cicd_deployment_commits.commit_sha is copied directly from cicd_pipeline_commits.commit_sha (the pipeline-reported SHA), not independently derived as a merge or head commit 1 2. For DORA Lead Time, this means the deployment tool must report the merged commit SHA for the join to succeed.

Linking Mechanism#

The DORA plugin's calculateChangeLeadTime task iterates over all PRs and, for each PR, calls getDeploymentCommit(pr.MergeCommitSha) 3. That helper executes a single query that:

1. Joins cicd_deployment_commits dc → prior successful deployment commit p via dc.prev_success_deployment_commit_id = p.id 4
2. Joins commits_diffs cd where cd.new_commit_sha = dc.commit_sha AND cd.old_commit_sha = COALESCE(p.commit_sha, '') — this constrains the search to commits introduced by one deployment window 4
3. Joins project_mapping pm to scope the query to the current project
4. Filters on cd.commit_sha = <PR merge SHA>, dc.environment = PRODUCTION, dc.result = SUCCESS, and a non-empty prev_success_deployment_commit_id 5
5. Orders by deployment start date + ID ascending, LIMIT 1 — returns the earliest production deployment that contained the PR's merge commit 5

In plain terms: a PR is considered "deployed" when its merge commit SHA appears in the commits_diffs diff window between two consecutive successful production deployments.

DORA Pipeline Stages That Enable the Link#

The DORA plugin runs a three-stage pipeline 6:

1. Stage 1 — generateDeploymentCommits builds cicd_deployment_commits; enrichPrevSuccessDeploymentCommits sets PrevSuccessDeploymentCommitId on each row to bound the diff range.
2. Stage 2 — refdiff's calculateDeploymentCommitsDiff walks the git graph between consecutive deployment SHAs and writes commits_diffs rows 7 8.
3. Stage 3 — calculateChangeLeadTime performs the PR-to-deployment join described above and writes results to project_pr_metrics.

Per-Tool commit_sha Population#

Each connector plugin is responsible for supplying the correct commit SHA when writing cicd_pipeline_commits. Examples:

• Azure DevOps — uses build.SourceVersion (the pipeline trigger SHA) 9
• GitHub (GraphQL) — maps GithubDeployment → CicdDeploymentCommit, with environment classification via user-configured regex 10

If a tool reports the branch tip SHA rather than the merge commit SHA, the commits_diffs join will still find the PR's commits as long as they are reachable in the commit graph between the two deployment SHAs.

Key Files#