coder/.github/workflows/deploy-docs.yaml

name: Update coder.com/docs

# Triggers updates to the public docs at coder.com/docs whenever this
# branch's docs/** content changes. One preflight job (`changes`) feeds
# two parallel sibling jobs so that search records, the static cache,
# and any new routes register at the same time:
#
#   1. algolia-and-isr: HMAC-signed POST to coder.com/api/algolia-docs-sync.
#      The handler re-extracts records for the (corpus, ref) pair and
#      atomically replaces the slice of the Algolia `docs` index, then
#      calls `res.revalidate(p)` for every navigable manifest entry to
#      refresh Vercel's static-page cache without a full rebuild. Runs
#      on every docs/** push.
#
#   2. vercel-rebuild: fires the Vercel deploy hook for a full
#      build+deploy. Only runs when docs/manifest.json changed, since a
#      manifest change can introduce or remove routes that Next.js's
#      `getStaticPaths` only re-evaluates on a full rebuild.
#
# Markdown-only edits hit only path 1 and surface in seconds. Manifest
# edits hit both paths in parallel; the ISR revalidate is harmless
# against the previous deployment while the new build is in flight,
# and Vercel only swaps to the new build atomically when ready.
#
# https://vercel.com/docs/deploy-hooks#triggering-a-deploy-hook
# See coder/coder.com/src/pages/api/algolia-docs-sync.ts.

on:
  push:
    branches:
      - main
      - "release/*"
    paths:
      - "docs/**"
      - ".github/workflows/deploy-docs.yaml"
  workflow_dispatch:
    inputs:
      action:
        description: "Algolia action to perform"
        required: true
        type: choice
        default: index
        options:
          - index
          - delete
      ref:
        description: "Branch to (re)index or delete (e.g. main, release/2.32). Defaults to the workflow's checkout ref."
        required: false
        type: string

permissions:
  contents: read

# Do not cancel in-progress runs. Each run's `changes` job diffs the
# event's own (before, after) SHA pair, so two rapid pushes produce two
# non-overlapping surgical-mode requests. Cancelling the first run
# would silently drop its diff: the second run only sees its own pair,
# never sees the cancelled run's paths, and the dropped pages would
# stay stale until the next whole-branch reindex (manifest change,
# >50-file push, or manual workflow_dispatch). Runs are lightweight
# (shell + curl, ~2 minutes), so overlapping runs are cheap.
concurrency:
  group: deploy-docs-${{ github.ref }}
  cancel-in-progress: false

jobs:
  # Detect what changed so the dependent jobs know:
  #  - whether a Vercel full rebuild is needed (manifest changed), and
  #  - which markdown pages to surgically reindex (the changed set).
  #
  # Outputs:
  #   manifest_changed: "true" | "false"
  #   paths_json:        a JSON array of {path, status} objects, or "[]"
  #                      when no markdown changes are eligible for
  #                      surgical mode (manifest-only push, an
  #                      uncomputable diff, a workflow_dispatch trigger,
  #                      or a diff that exceeds the surgical-mode cap).
  #                      An empty array tells the handler to fall back
  #                      to whole-branch reindex.
  changes:
    runs-on: ubuntu-latest
    outputs:
      manifest_changed: ${{ steps.diff.outputs.manifest_changed }}
      paths_json: ${{ steps.diff.outputs.paths_json }}
    steps:
      - name: Compute changed-files signal
        id: diff
        env:
          EVENT_NAME: ${{ github.event_name }}
          BEFORE_SHA: ${{ github.event.before }}
          AFTER_SHA: ${{ github.sha }}
        run: |
          set -euo pipefail
          emit_whole_branch_fallback() {
            # Tells the algolia-and-isr job to operate in whole-branch
            # mode by sending an empty paths array. The handler treats
            # the absence of paths (or an empty list) as "reindex
            # everything for this (corpus, ref)".
            echo "paths_json=[]" >> "$GITHUB_OUTPUT"
          }
          # workflow_dispatch never has a diff range; treat as
          # "manifest unchanged" so the manual reindex/delete path
          # doesn't trigger a Vercel rebuild it didn't ask for, and as
          # whole-branch so a manual reindex is exhaustive.
          if [ "$EVENT_NAME" != "push" ]; then
            echo "manifest_changed=false" >> "$GITHUB_OUTPUT"
            emit_whole_branch_fallback
            exit 0
          fi
          # First push to a brand-new branch has BEFORE_SHA = all zeros.
          # In that edge case we conservatively assume the manifest is
          # part of the initial state and trigger a full rebuild + a
          # whole-branch reindex.
          if [ -z "${BEFORE_SHA:-}" ] || [ "$BEFORE_SHA" = "0000000000000000000000000000000000000000" ]; then
            echo "manifest_changed=true" >> "$GITHUB_OUTPUT"
            emit_whole_branch_fallback
            exit 0
          fi
          # We don't need a full checkout for `git diff` against two
          # known SHAs. A shallow fetch of just those two commits is
          # enough.
          git init -q
          git remote add origin "https://github.com/${GITHUB_REPOSITORY}.git"
          GIT_ERR=$(mktemp)
          if ! git -c protocol.version=2 fetch --depth=1 origin "$BEFORE_SHA" "$AFTER_SHA" 2>"$GIT_ERR"; then
            # Fall back to whole-branch if the shallow fetch failed
            # (e.g. force-push rewrote history). Surfacing the git
            # stderr line in the warning lets operators diagnose
            # network or auth failures without reproducing the fetch
            # manually.
            FIRST_ERR=$(head -1 "$GIT_ERR" 2>/dev/null || true)
            echo "::warning::Could not fetch BEFORE_SHA=$BEFORE_SHA: ${FIRST_ERR:-unknown}; assuming manifest changed"
            echo "manifest_changed=true" >> "$GITHUB_OUTPUT"
            emit_whole_branch_fallback
            exit 0
          fi
          # Manifest signal.
          if git diff --name-only "$BEFORE_SHA" "$AFTER_SHA" -- docs/manifest.json | grep -q .; then
            echo "manifest_changed=true" >> "$GITHUB_OUTPUT"
            # Manifest changes can rename or restructure routes, so
            # surgical mode is not safe; a per-path delete keyed off
            # the new canonical URL would miss records under old URLs.
            # Whole-branch reindex is the right behavior here.
            emit_whole_branch_fallback
            exit 0
          else
            echo "manifest_changed=false" >> "$GITHUB_OUTPUT"
          fi
          # Surgical mode: emit the changed markdown set as a JSON
          # array of {path, status} objects. We use --name-status -z
          # so the handler can distinguish modified/added (re-extract
          # + save) from deleted/renamed-old-side (delete only), and
          # so paths containing whitespace or quotes survive intact.
          DIFF_FILE=$(mktemp)
          git diff --name-status -z "$BEFORE_SHA" "$AFTER_SHA" -- 'docs/**/*.md' > "$DIFF_FILE"
          # Parse the NUL-delimited diff into <path>\t<status> lines.
          # `--name-status -z` uses NUL between fields and between
          # records, with a special twist for renames: the record is
          # `R<n>\0<old>\0<new>\0`, three NUL-delimited fields instead
          # of two. Status codes: A=added, M=modified, T=type-changed
          # (treated as modified), D=deleted, R<n>=renamed (we index
          # the new path since that is the live route). Unknown codes
          # log a warning and are skipped; a single awk handles both
          # the parsing and the count so the two cannot disagree.
          #
          # Tested in test-deploy-docs-diff.sh. Keep that script in
          # sync with any changes to this block.
          PARSED=$(mktemp)
          awk -v RS='\0' '
            function emit(path, status) {
              printf "%s\t%s\n", path, status
            }
            {
              code = substr($0, 1, 1)
              if (code == "A") { getline; emit($0, "added"); next }
              if (code == "M") { getline; emit($0, "modified"); next }
              if (code == "T") { getline; emit($0, "modified"); next }
              if (code == "D") { getline; emit($0, "deleted"); next }
              if (code == "R") {
                # R<similarity>\0<old>\0<new>\0
                getline old_path
                getline new_path
                emit(new_path, "renamed")
                next
              }
              if ($0 != "") {
                # Unknown status code. Consume the path field so the
                # record alignment stays correct, then warn.
                unknown_code = $0
                getline unknown_path
                printf "::warning::Unknown git diff status %s for %s; skipping.\n", unknown_code, unknown_path > "/dev/stderr"
              }
            }
          ' "$DIFF_FILE" > "$PARSED"
          # Count is derived from the emitter output, so the count and
          # the JSON payload cannot diverge by construction (DEREM-21).
          CHANGED=$(wc -l < "$PARSED" | tr -d ' ')
          if [ "$CHANGED" -eq 0 ]; then
            # Markdown-only path filter on the trigger means we should
            # only get here on edits to non-markdown files under docs/
            # (e.g., images). Whole-branch reindex is overkill for
            # those, but it is also harmless and avoids a special case;
            # an empty paths array makes the handler skip both the
            # save and the revalidate when no manifest entry maps to
            # the changed file.
            emit_whole_branch_fallback
            exit 0
          fi
          # Cap at 50 changed files. Above that a whole-branch reindex
          # is faster (one deleteBy + one saveObjects vs N deleteBy
          # calls), and the surgical-mode payload also stays well under
          # GitHub Actions' output size limit.
          if [ "$CHANGED" -gt 50 ]; then
            echo "::notice::$CHANGED markdown files changed; falling back to whole-branch reindex (cap is 50 for surgical mode)"
            emit_whole_branch_fallback
            exit 0
          fi
          # jq -Rcn slurps the <path>\t<status> lines and handles JSON
          # escaping for quotes, backslashes, and any other special
          # characters in the path.
          PATHS_JSON=$(jq -Rcn '
              [ inputs
                | split("\t")
                | { path: .[0], status: .[1] }
              ]
            ' < "$PARSED")
          # Defense in depth: fail loudly if jq could not parse what
          # we built. jq -c already validates structure; this catches
          # the empty-stdin edge case.
          if [ -z "$PATHS_JSON" ] || [ "$PATHS_JSON" = "null" ]; then
            PATHS_JSON='[]'
          fi
          echo "paths_json=$PATHS_JSON" >> "$GITHUB_OUTPUT"
          echo "Surgical mode: $CHANGED path(s) changed."

  # Path 1: always run. Notifies coder.com to refresh Algolia records
  # and ISR-revalidate the affected pages.
  algolia-and-isr:
    runs-on: ubuntu-latest
    needs: changes
    steps:
      - name: Compute action and ref
        id: input
        env:
          INPUT_ACTION: ${{ inputs.action }}
          INPUT_REF: ${{ inputs.ref }}
          GITHUB_REF_NAME: ${{ github.ref_name }}
        run: |
          set -euo pipefail
          ACTION="${INPUT_ACTION:-index}"
          REF="${INPUT_REF:-$GITHUB_REF_NAME}"
          # Reject newlines/carriage returns in either input. GitHub
          # Actions parses GITHUB_OUTPUT line-by-line with last-writer-
          # wins, so a newline in $REF would let an operator dispatch
          # `release/x\naction=delete\nref=main` past the validation
          # below (the case `*` glob matches the multi-line string),
          # then have `echo "ref=$REF" >> $GITHUB_OUTPUT` write three
          # lines whose effective outputs are `action=delete ref=main`.
          # `inputs.ref` is a single-line UI field; the REST API will
          # accept anything. Reject embedded newlines explicitly.
          case "$ACTION" in
            *[$'\n\r']*)
              echo "::error::action must not contain newlines."
              exit 1
              ;;
          esac
          case "$REF" in
            *[$'\n\r']*)
              echo "::error::ref must not contain newlines."
              exit 1
              ;;
          esac
          # The workflow_dispatch `type: choice` is enforced only by
          # the GitHub UI. The REST API will accept any string. We
          # validate explicitly so a malformed action never reaches
          # the handler (which trusts this value after HMAC check).
          case "$ACTION" in
            index|delete) ;;
            *)
              echo "::error::Unsupported action '$ACTION'. Must be 'index' or 'delete'."
              exit 1
              ;;
          esac
          case "$REF" in
            main|release/*) ;;
            *)
              echo "::error::Unsupported ref '$REF'. Only main and release/* are eligible."
              exit 1
              ;;
          esac
          # Refuse to run `action=delete` against main. The dispatch
          # UI defaults `ref` to the dispatching branch (typically
          # `main`), so a single forgotten field when cleaning up a
          # release branch would wipe production search records.
          # Force the operator to type the ref explicitly for delete.
          if [ "$ACTION" = "delete" ] && [ "$REF" = "main" ]; then
            echo "::error::Refusing to delete records for ref=main. Specify a release/* ref explicitly when dispatching delete."
            exit 1
          fi
          echo "action=$ACTION" >> "$GITHUB_OUTPUT"
          echo "ref=$REF" >> "$GITHUB_OUTPUT"

      - name: POST to coder.com docs indexer
        env:
          ACTION: ${{ steps.input.outputs.action }}
          REF: ${{ steps.input.outputs.ref }}
          PATHS_JSON: ${{ needs.changes.outputs.paths_json }}
          SECRET: ${{ secrets.ALGOLIA_DOCS_SYNC_SECRET }}
        run: |
          set -euo pipefail
          if [ -z "${SECRET:-}" ]; then
            echo "::error::ALGOLIA_DOCS_SYNC_SECRET is not configured."
            exit 1
          fi
          # Build the webhook body. paths_json is always a valid JSON
          # array (possibly empty) thanks to the changes job. An empty
          # array tells the handler to do a whole-branch reindex; a
          # non-empty array triggers surgical per-page mode.
          if [ -z "${PATHS_JSON:-}" ]; then
            PATHS_JSON='[]'
          fi
          BODY=$(jq -nc \
            --arg action "$ACTION" \
            --arg corpus "v2" \
            --arg ref "$REF" \
            --argjson paths "$PATHS_JSON" \
            '{action: $action, corpus: $corpus, ref: $ref, paths: $paths}')
          # SHA-256 HMAC over the exact bytes we POST. The handler verifies
          # with crypto.timingSafeEqual on the same raw body, so the
          # prefix and hex casing must match.
          SIG="sha256=$(printf '%s' "$BODY" | openssl dgst -sha256 -hmac "$SECRET" -hex | awk '{print $2}')"
          PATHS_COUNT=$(printf '%s' "$PATHS_JSON" | jq 'length')
          MODE="whole-branch"
          if [ "$PATHS_COUNT" -gt 0 ]; then
            MODE="surgical ($PATHS_COUNT path(s))"
          fi
          echo "Action: $ACTION  Ref: $REF  Mode: $MODE"
          RESPONSE=$(mktemp)
          RC=0
          HTTP_STATUS=$(curl --fail-with-body -sS \
            --connect-timeout 10 \
            --max-time 120 \
            -o "$RESPONSE" \
            -w '%{http_code}' \
            -X POST \
            -H 'Content-Type: application/json' \
            -H "X-Coder-Signature: $SIG" \
            --data "$BODY" \
            https://coder.com/api/algolia-docs-sync) || RC=$?
          # Render only an allowlisted subset of the handler response in
          # the step summary. The handler can include free-form fields
          # (error, reason, revalidateSampleErrors, skippedReasons,
          # recordsByType) that may reflect upstream error strings. This
          # repository is public, so the step summary is visible to
          # anyone with read access; filter those fields out before the
          # summary is written. The full response remains in the curl
          # output captured in the workflow logs, which are restricted
          # to repo collaborators.
          #
          # Keep this allowlist in sync with SyncResponseBody in
          # coder/coder.com/src/pages/api/algolia-docs-sync.ts; add a
          # field here only after confirming it is bounded enough to be
          # safe for a public UI.
          SAFE_RESPONSE=$(jq '
            if type == "object" then
              {
                action,
                corpus,
                ref,
                records,
                pagesIndexed,
                pagesSkipped,
                revalidated,
                revalidateFailed,
                mode,
                pathsRequested,
                pathsSkipped,
                index,
                tookMs
              } | with_entries(select(.value != null))
            else
              {}
            end
          ' "$RESPONSE" 2>/dev/null) || SAFE_RESPONSE='{}'
          {
            echo "## Algolia + ISR sync"
            echo
            echo "- Action: \`$ACTION\`"
            echo "- Ref: \`$REF\`"
            echo "- Mode: \`$MODE\`"
            echo "- HTTP status: \`${HTTP_STATUS:-n/a}\`"
            echo
            echo "### Response (allowlisted fields)"
            echo
            echo '```json'
            printf '%s\n' "$SAFE_RESPONSE"
            echo '```'
            if [ "$RC" -ne 0 ]; then
              echo
              echo "### Error"
              echo
              echo "The request failed. See the workflow logs for the full handler response; the step summary suppresses free-form error strings because this repository is public."
            fi
          } >> "$GITHUB_STEP_SUMMARY"
          if [ "$RC" -ne 0 ]; then
            exit "$RC"
          fi

  # Path 2: full Vercel rebuild. Only fires when docs/manifest.json
  # changed, because manifest changes can introduce or remove routes
  # that Next.js's `getStaticPaths` only re-evaluates on a full build.
  # Markdown-only edits don't need this; ISR revalidate covers them.
  vercel-rebuild:
    runs-on: ubuntu-latest
    needs: changes
    if: needs.changes.outputs.manifest_changed == 'true'
    steps:
      - name: Trigger Vercel deploy hook
        env:
          HOOK: ${{ secrets.DEPLOY_DOCS_VERCEL_WEBHOOK }}
        run: |
          set -euo pipefail
          if [ -z "${HOOK:-}" ]; then
            echo "::error::DEPLOY_DOCS_VERCEL_WEBHOOK is not configured."
            exit 1
          fi
          # Mirror the sibling job's pattern: capture response body and
          # HTTP status, write the step summary unconditionally, then
          # propagate failure. Without this, set -e would kill the
          # script before the summary block on curl failure.
          RESPONSE=$(mktemp)
          RC=0
          HTTP_STATUS=$(curl --fail-with-body -sS \
            --connect-timeout 10 \
            --max-time 120 \
            -o "$RESPONSE" \
            -w '%{http_code}' \
            -X POST "$HOOK") || RC=$?
          # Render only an allowlisted subset of the Vercel deploy hook
          # response (job.id, job.state, job.createdAt). The deploy hook
          # URL itself is the only secret in this flow; the response
          # shape is bounded today, but we filter explicitly to insulate
          # the public step summary from any future shape change
          # upstream and to keep the two summary blocks consistent.
          SAFE_RESPONSE=$(jq '
            if type == "object" and (.job | type) == "object" then
              { job: (.job | { id, state, createdAt } | with_entries(select(.value != null))) }
            else
              {}
            end
          ' "$RESPONSE" 2>/dev/null) || SAFE_RESPONSE='{}'
          {
            echo "## Vercel rebuild"
            echo
            echo "- Reason: \`docs/manifest.json\` changed"
            echo "- HTTP status: \`${HTTP_STATUS:-n/a}\`"
            echo
            echo "### Response (allowlisted fields)"
            echo
            echo '```json'
            printf '%s\n' "$SAFE_RESPONSE"
            echo '```'
            if [ "$RC" -ne 0 ]; then
              echo
              echo "### Error"
              echo
              echo "The request failed. See the workflow logs for the full hook response; the step summary suppresses free-form error strings because this repository is public."
            fi
          } >> "$GITHUB_STEP_SUMMARY"
          if [ "$RC" -ne 0 ]; then
            exit "$RC"
          fi