Blog publish labels

The blog-publish-labels.yml workflow runs daily at 7 AM UTC. It executes blog-publish-check.sh, which iterates over all open PRs with the blog label and calls pr-approval-labels.sh for each one. When ready-to-be-merged is newly applied to any of them, a Slack notification is posted. The labeling step uses continue-on-error: true, so the Slack notification step runs even if individual PR processing fails.

For details on the approval labels managed by the script, see Label gate.

The Slack notification fires only when the label transitions from absent to present on that run — repeated daily runs for an already-labeled PR do not re-notify. The workflow can also be triggered manually via workflow_dispatch with the force_notify input set to true to send a one-off test notification without applying any labels (dry run).

Workflow sequence

sequenceDiagram
    participant GH as GitHub
    participant W as blog-publish-labels
    participant B as blog-publish-check.sh
    participant L as pr-approval-labels.sh
    participant S as Slack

    Note over GH: schedule event (daily, 7 AM UTC)

    GH->>W: Trigger (base repository context, with secrets)
    W->>B: Run blog-publish-check.sh
    B->>GH: Query open PRs with PUBLISH_DATE_LABELS labels
    GH-->>B: List of PRs
    loop Each PR
        B->>L: Run pr-approval-labels.sh (PR=number)
        L->>GH: Add/remove labels
    end
    alt Any PR newly labeled ready-to-be-merged
        W->>S: POST Slack notification with PR links
    end

Security model

The workflow runs on a schedule, which always executes in the trusted base repository context (schedule events have no fork variant). It uses a GitHub App token (OTELBOT_DOCS_APP_ID / OTELBOT_DOCS_PRIVATE_KEY) for label edits and org/team reads, and the SLACK_WEBHOOK_URL secret to post notifications.

Slack webhook setup

The workflow uses a Slack Workflow Builder webhook trigger, which allows non-engineers to own the message format without touching workflow code.

Create the webhook:

1. In Slack: Tools → Workflow Builder → New Workflow → Start from scratch

2. Choose trigger: Webhook

3. Declare one variable — name: pr_list, type: Text

4. Add a step: Send a message to the desired channel, with body:

   :newspaper: *Blog posts ready to publish*
   
   The following PRs have reached their publish date and all required
   approvals — they are ready to be merged:
   
   {{pr_list}}
   
   Have a great day! :sunny:
   

   Then click Add button and configure:

   • Label: Review and merge
   • Color: Primary (green)
   • Action: Open a link
   • URL: https://github.com/open-telemetry/opentelemetry.io/issues?q=is%3Apr+state%3Aopen+label%3Ablog+label%3Aready-to-be-merged

5. Publish the workflow and copy the webhook URL

6. Add it to the repository: Settings → Secrets and variables → Actions → New repository secret, name: SLACK_WEBHOOK_URL

Payload sent by the workflow:

{
  "pr_list": "• #123: Add blog post: OTel 1.0 — https://github.com/.../pull/123\n• #456: Announce: new SIG — https://github.com/.../pull/456"
}

Each PR is a bulleted line with its title and URL. Slack auto-links bare URLs. Multiple PRs labeled on the same day are batched into a single message — one webhook call regardless of how many PRs are ready.