notify-slack-on-label.yml

name: Notify Slack on Labeled Issue or PR

on:
  issues:
    types: [labeled]
  pull_request:
    types: [labeled]

jobs:
  notify:
    runs-on: ubuntu-latest
    steps:
      - name: Notify Slack Channel Based on Label
        uses: actions/github-script@v7
        with:
          script: |
            // ── Label → Slack webhook secret name mapping ──────────────────────
            // Add or remove entries here as you add/remove Ray library channels.
            // The key is the GitHub label name; the value is the name of the
            // GitHub Actions secret that holds that channel's Incoming Webhook URL.
            const LABEL_TO_SECRET = {
              "serve":        "SLACK_WEBHOOK_SERVE",
              "train":        "SLACK_WEBHOOK_TRAIN",
              "tune":         "SLACK_WEBHOOK_TUNE",
              "rllib":        "SLACK_WEBHOOK_RLLIB",
              "data":         "SLACK_WEBHOOK_DATA",
              "air":          "SLACK_WEBHOOK_AIR",
              "core":         "SLACK_WEBHOOK_CORE",
              "workflow":     "SLACK_WEBHOOK_WORKFLOW",
              "cluster":      "SLACK_WEBHOOK_CLUSTER",
            };

            // ── Resolve the webhook URLs from secrets ──────────────────────────
            // We pass secrets in as env vars so the script can read them safely.
            const SECRET_VALUES = {
              "SLACK_WEBHOOK_SERVE":    process.env.SLACK_WEBHOOK_SERVE,
              "SLACK_WEBHOOK_TRAIN":    process.env.SLACK_WEBHOOK_TRAIN,
              "SLACK_WEBHOOK_TUNE":     process.env.SLACK_WEBHOOK_TUNE,
              "SLACK_WEBHOOK_RLLIB":    process.env.SLACK_WEBHOOK_RLLIB,
              "SLACK_WEBHOOK_DATA":     process.env.SLACK_WEBHOOK_DATA,
              "SLACK_WEBHOOK_AIR":      process.env.SLACK_WEBHOOK_AIR,
              "SLACK_WEBHOOK_CORE":     process.env.SLACK_WEBHOOK_CORE,
              "SLACK_WEBHOOK_WORKFLOW": process.env.SLACK_WEBHOOK_WORKFLOW,
              "SLACK_WEBHOOK_CLUSTER":  process.env.SLACK_WEBHOOK_CLUSTER,
            };

            // ── Determine event type and payload ──────────────────────────────
            const isPR    = !!context.payload.pull_request;
            const item    = isPR ? context.payload.pull_request : context.payload.issue;
            const type    = isPR ? "Pull Request" : "Issue";
            const action  = context.payload.action;           // "opened" | "labeled"
            const labels  = (item.labels || []).map(l => l.name);

            // On "labeled" events, only act on the label that was just added
            // (avoids duplicate messages when multiple labels already exist).
            const triggeredLabel = action === "labeled"
              ? context.payload.label.name
              : null;

            const labelsToProcess = triggeredLabel ? [triggeredLabel] : labels;

            // ── Send a message for each matching label ─────────────────────────
            for (const label of labelsToProcess) {
              const secretName = LABEL_TO_SECRET[label];
              if (!secretName) continue;                      // label not mapped

              const webhookUrl = SECRET_VALUES[secretName];
              if (!webhookUrl) {
                core.warning(`Secret ${secretName} is not set — skipping #${label}`);
                continue;
              }

              // Build a rich Slack Block Kit message
              const allLabelNames = labels.map(l => `\`${l}\``).join(" ");
              const body = {
                blocks: [
                  {
                    type: "section",
                    text: {
                      type: "mrkdwn",
                      text: `*New ${type} in <https://github.com/${context.repo.owner}/${context.repo.repo}|${context.repo.owner}/${context.repo.repo}>*`
                    }
                  },
                  {
                    type: "section",
                    fields: [
                      { type: "mrkdwn", text: `*Title*\n<${item.html_url}|${item.title}>` },
                      { type: "mrkdwn", text: `*Author*\n<${item.user.html_url}|${item.user.login}>` },
                      { type: "mrkdwn", text: `*Labels*\n${allLabelNames || "_none_"}` },
                      { type: "mrkdwn", text: `*#*\n${item.number}` },
                    ]
                  },
                  ...(item.body ? [{
                    type: "section",
                    text: {
                      type: "mrkdwn",
                      // Truncate long bodies so the message stays readable
                      text: `*Description*\n${item.body.slice(0, 300)}${item.body.length > 300 ? "…" : ""}`
                    }
                  }] : []),
                  {
                    type: "actions",
                    elements: [
                      {
                        type: "button",
                        text: { type: "plain_text", text: `View ${type}` },
                        url: item.html_url,
                        style: "primary"
                      }
                    ]
                  }
                ]
              };

              const response = await fetch(webhookUrl, {
                method: "POST",
                headers: { "Content-Type": "application/json" },
                body: JSON.stringify(body)
              });

              if (!response.ok) {
                core.error(`Failed to post to Slack for label "${label}": ${response.status} ${response.statusText}`);
              } else {
                core.info(`Posted to Slack channel for label "${label}"`);
              }
            }
        env:
          SLACK_WEBHOOK_SERVE:    ${{ secrets.SLACK_WEBHOOK_SERVE }}
          SLACK_WEBHOOK_TRAIN:    ${{ secrets.SLACK_WEBHOOK_TRAIN }}
          SLACK_WEBHOOK_TUNE:     ${{ secrets.SLACK_WEBHOOK_TUNE }}
          SLACK_WEBHOOK_RLLIB:    ${{ secrets.SLACK_WEBHOOK_RLLIB }}
          SLACK_WEBHOOK_DATA:     ${{ secrets.SLACK_WEBHOOK_DATA }}
          SLACK_WEBHOOK_AIR:      ${{ secrets.SLACK_WEBHOOK_AIR }}
          SLACK_WEBHOOK_CORE:     ${{ secrets.SLACK_WEBHOOK_CORE }}
          SLACK_WEBHOOK_WORKFLOW: ${{ secrets.SLACK_WEBHOOK_WORKFLOW }}
          SLACK_WEBHOOK_CLUSTER:  ${{ secrets.SLACK_WEBHOOK_CLUSTER }}