cleanup-workflows.yml

# Manual workflow to cleanup deleted workflows runs.
#
# Github keeps workflows runs around even if the workflow is deleted.
# This has the side effect that these still display in the UI which gets cluttered.
# Once the runs of a workflow are deleted, they also get removed from the UI.
name: Cleanup Workflow

on:
  workflow_dispatch:
    inputs:
      mode:
        description: "Choose 'dry run' to preview or 'execute' to delete runs"
        required: true
        default: "dry run"
        type: choice
        options:
          - "dry run"
          - "execute"

jobs:
  cleanup:
    name: Cleanup deleted workflows
    runs-on: ubuntu-latest
    permissions:
      actions: write # required for deleting workflow runs
      contents: read

    steps:
      - name: Checkout repo
        uses: actions/checkout@v6
        with:
          fetch-depth: 0

      - name: Workflows on main
        id: main
        run: |
          git fetch origin main
          WORKFLOWS=$(git ls-tree -r origin/main --name-only | grep '^.github/workflows/')
          printf "%s\n" $WORKFLOWS
          {
            echo "workflows<<EOF"
            echo "$WORKFLOWS"
            echo "EOF"
          } >> "$GITHUB_OUTPUT"

      - name: Workflows on next
        id: next
        run: |
          git fetch origin next
          WORKFLOWS=$(git ls-tree -r origin/next --name-only | grep '^.github/workflows/')
          printf "%s\n" $WORKFLOWS
          {
            echo "workflows<<EOF"
            echo "$WORKFLOWS"
            echo "EOF"
          } >> "$GITHUB_OUTPUT"

      - name: Filter for deleted workflows
        id: deleted
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          set -euo pipefail

          # Union of `main` and `next` workflows as a JSON array of strings (paths)
          EXISTING=$(printf "%s\n%s\n" \
            "${{ steps.main.outputs.workflows }}" \
            "${{ steps.next.outputs.workflows }}" \
          )
          EXISTING=$(echo "$EXISTING" | sort -u | jq -R . | jq -s .)

          echo "Existing workflows:"
          echo "$EXISTING"

          # Get workflows currently on GitHub as JSON array of objects
          GITHUB=$(gh api repos/{owner}/{repo}/actions/workflows \
            --jq '.workflows[] | select(.path | startswith(".github")) | { name, node_id, path }' \
              | jq -s '.')

          echo "Workflows on GitHub:"
          echo "$GITHUB"

          # Find deleted workflows: present on GitHub but not in main/next
          DELETED=$(echo "$GITHUB" | jq -c \
            --argjson existing "$EXISTING" '
              map(select(.path as $p | $existing | index($p) | not))
            '
          )

          echo "Deleted workflows:"
          echo "$DELETED"

          # Output to GitHub Actions
          {
            echo "workflows<<EOF"
            echo "$DELETED"
            echo "EOF"
          } >> "$GITHUB_OUTPUT"

      # Performs the actual run deletion.
      #
      # This contains a lot of code, but the vast majority is just pretty-printing.
      - name: Delete runs from deleted workflows
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          MODE: ${{ inputs.mode }}
          WORKFLOWS: ${{ steps.deleted.outputs.workflows }}
          OWNER: ${{ github.repository_owner }}
          REPO: ${{ github.repository }}
        shell: bash --noprofile --norc -euo pipefail {0}
        run: |
          if [ -z "$WORKFLOWS" ]; then
            echo "No workflows to delete."
            exit 0
          fi

          # ================================================================================================
          # Utility functions
          # ================================================================================================

          # Fetches a page of workflow runs for a given workflow ID and cursor.
          #
          # We use github's graphql API here which allows us to paginate over workflow runs.
          # Unfortunately `gh run list` does not support pagination, so we use the graphql API instead.
          gh_workflow_run_page() {
            local id="$1"
            local cursor="$2"

            gh api graphql -F workflowId="$id" -F after="$cursor" \
              -f query='query($workflowId: ID!, $after: String) {
                  node(id: $workflowId) {
                    ... on Workflow {
                      runs(first: 100, after: $after) {
                        pageInfo { hasNextPage endCursor }
                        nodes { databaseId }
                      }
                    }
                  }
                }'
          }

          # ================================================================================================
          # Print helpers for nice progress and table display
          # ================================================================================================

          # Column widths (table includes three spacers for ' | ' between columns)
          widths_index=9
          widths_name=30
          widths_count=14
          widths_total=12
          widths_table=$(( $widths_index + 3 + $widths_name + 3 + $widths_count + 3 + $widths_total ))

          # Repeats a character a given number of times.
          repeat_char() {
            local char=$1
            local count=$2
            printf "%0.s$char" $(seq 1 $count)
          }

          # Prints the given header as `==== <header> ====` to match the table layout.
          print_table_header() {
            local header="$1"
            local header_len=${#header}
            local left_pad=$(( ( $widths_table - header_len - 2) / 2 ))
            local right_pad=$(( $widths_table - header_len - 2 - left_pad ))
            printf " \n%s %s %s\n" $(repeat_char = $left_pad) "$header" $(repeat_char = $right_pad)
          }

          # Prints |---+---+---+---| with appropriate widths to accomodate the table headers.
          print_table_separator() {
            printf "%s+%s+%s+%s\n"                     \
              "$(repeat_char - $((widths_index + 1)))" \
              "$(repeat_char - $((widths_name + 2)))"  \
              "$(repeat_char - $((widths_count + 2)))" \
              "$(repeat_char - $((widths_total + 1)))"
          }

          # Prints a row of the table (index, workflow name, workflow count, global total)
          print_table_row() {
            local index=$1
            local name=$2
            local count=$3
            local total=$4
            printf "%*s | %-*s | %*s | %*s\n"  \
              "$widths_index" "$index"          \
              "$widths_name" "$name"            \
              "$widths_count" "$count"          \
              "$widths_total" "$total"
          }

          # Alias for print_table_row() with empty index and total columns.
          print_summary_row() {
            local name=$1
            local count=$2
            print_table_row "" "$name" "$count" ""
          }

          # ================================================================================================
          # Print progress table header
          # ================================================================================================
          print_table_header "Workflow Cleanup Progress"
          print_table_row "Index" "Workflow" "Workflow Count" "Global Total"
          print_table_separator

          # ================================================================================================
          # Core workflow loop, iterate over workflows
          # ================================================================================================

          n_workflows=$(echo "$WORKFLOWS" | jq -r '. | length')
          total=0
          summary=()
          index=0

          mapfile -t WF_ARRAY < <(echo "$WORKFLOWS" | jq -c '.[]')
          for wf in "${WF_ARRAY[@]}"; do
            index=$((index + 1))
            name=$(echo "$wf" | jq -r '.name')
            count=0
            id=$(echo "$wf" | jq -r '.node_id')

            # Safety checks
            if [ -z "$name" ]; then
              echo "::error title=Workflow name empty::Resolved workflow name is empty at index $index"
              exit 1
            fi
            if [ -z "$id" ]; then
              echo "::error title=Workflow ID missing::Workflow '$name' has no ID"
              exit 1
            fi

            cursor=""

            # Paginate over workflow runs
            while true; do
              response=$(gh_workflow_run_page "$id" "$cursor")

              run_ids=$(echo "$response" | jq -r '.data.node.runs.nodes[].databaseId')
              has_next=$(echo "$response" | jq -r '.data.node.runs.pageInfo.hasNextPage')
              cursor=$(echo "$response" | jq -r '.data.node.runs.pageInfo.endCursor')

              [ -z "$run_ids" ] && break

              deleted=$(echo "$run_ids" | wc -l | tr -d ' ')
              count=$((count + deleted))
              total=$((total + deleted))

              # Print progress
              print_table_row "[$index/$n_workflows]" "$name" "$count" "$total"

              if [ "$MODE" = "execute" ]; then
                for run_id in $run_ids; do
                  gh run delete "$run_id" >/dev/null
                done
              fi

              [ "$has_next" != "true" ] && break
            done

            summary+=("$name|$count")
          done

          # ================================================================================================
          # Print a summary table
          # ================================================================================================
          print_table_header "Workflow Cleanup Summary"
          print_summary_row "Workflow" "Runs"
          print_table_separator
          for entry in "${summary[@]}"; do
            wf="${entry%%|*}"
            count="${entry##*|}"
            print_summary_row "$wf" "$count"
          done

          # ================================================================================================
          # Print totals as a footer
          # ================================================================================================
          print_table_separator
          print_summary_row "TOTAL" "$total"

          if [ "$MODE" != "execute" ]; then
            echo "Dry run complete. No runs were deleted."
          else
            echo "Cleanup complete."
          fi