update-light-snapshot.yml

# The following code has been adapted from the Substrate Connect:
# https://github.com/paritytech/substrate-connect/blob/ef6418015c371430c0735d2b491447326406e5fd/.github/workflows/update-chain-specs.yml

name: light-client-snapshot-periodic-update

on:
  schedule:
    - cron: '0 9 * * MON'  # every Monday at 9am
  workflow_dispatch: # allow triggering through the UI


jobs:
  download-spec:
    runs-on: ubuntu-latest

    strategy:
      matrix:
        # This starts one parallel job for each of these addresses.
        rpc-node-address: [
          "wss://rpc.polkadot.io",
          "wss://kusama-rpc.polkadot.io",
          "wss://westend-rpc.polkadot.io",
        ]
      fail-fast: false   # Don't automatically cancel the jobs of the other RPC nodes if one fails

    steps:
      - uses: actions/checkout@v3.5.3
        with:
          persist-credentials: false
          path: repo
          ref: dev
      - run: |
          curl -L -O https://github.com/vi/websocat/releases/download/v1.9.0/websocat_linux64
          chmod +x websocat_linux64
      - run: |
          echo '{"id":1,"jsonrpc":"2.0","method":"sync_state_genSyncSpec","params":[true]}' |
            ./websocat_linux64 -n1 -B 99999999 ${{ matrix.rpc-node-address }} > rpc_answer.json
      - run: cat ./rpc_answer.json | jq .result > chain_spec.json
      - id: get-chain-id  # Reads the `id` field in the newly-downloaded chain spec
        run: echo "id=`jq -r .id ./chain_spec.json`" >> $GITHUB_OUTPUT
      - if: ${{ steps.get-chain-id.outputs.id == '' }}
        uses: actions/upload-artifact@v3
        with:
          name: failed-response-${{ github.run_id }}
          path: |
            rpc_answer.json
      - run: |  # Overwrite the `lightSyncState` field of the existing chain spec with the value of spec that's been downloaded.
          tmp=$(mktemp)
          output=./repo/src/main/webapp/genesis/${{ steps.get-chain-id.outputs.id }}.json
          jq --slurpfile downloaded ./chain_spec.json '.lightSyncState = $downloaded[0].lightSyncState' "$output" > "$tmp"
          mv "$tmp" "$output"
      - uses: actions/upload-artifact@v3
        with:
          name: chain-spec-${{ steps.get-chain-id.outputs.id }}
          # Note that passing `repo/**` maintains paths under `repo`. This is a bit of magic by the upload-artifact action.
          path: |
            repo/**/${{ steps.get-chain-id.outputs.id }}.json

  create-pr:
    runs-on: ubuntu-latest
    if: ${{ always() }}   # Run this job even if one of the steps of download-spec has failed
    needs: download-spec

    steps:
      - uses: actions/checkout@v3.5.3
        with:
          path: repo
          ref: dev
      - uses: actions/download-artifact@v3
        with:
          # Since we're not passing a name, this automatically downloads *all* artifacts
          # Unfortunately, this creates intermediary directories.
          path: .
      - run: cp -r ./chain-spec-*/* ./repo
      - uses: peter-evans/create-pull-request@v5
        with:
          # We use a custom secret (rather than the default GITHUB_TOKEN) so that opening the pull
          # request triggers other actions such as the CI checks. GitHub prevents actions that use
          # GITHUB_TOKEN from triggering further actions, to avoid recursive actions.
          token: ${{ secrets.GH_TOKEN }}
          committer: Fruzhin CICD <fruzhin-cicd@limechain.tech>
          author: Fruzhin CICD <fruzhin-cicd@limechain.tech>
          path: repo
          branch: automatic-checkpoints-update
          base: dev
          title: Update checkpoints in chain specifications
          # Note that the `download-spec` job above fails if the downloaded specification doesn't
          # correspond to an existing file. It is therefore impossible that the pull request
          # accidentally adds new specifications.
          body: >
            This pull request has been automatically generated by downloading chain
            specifications from various JSON-RPC endpoints and extracting their checkpoints.
            
            Keep in mind that introducing a malicious checkpoint can redirect users to the wrong
            chain. If this pull request looks suspicious, please be cautious.
          commit-message: Update checkpoints in chain specifications
          delete-branch: true