Add workflows

.github/workflows/sync-workflows.yml

@@ -0,0 +1,27 @@
+name: "Sync Workflows"
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+    paths:
+      - "mirror.txt"
+jobs:
+  sync-workflows:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Generate
+        run: |
+          git rm -f .github/workflows/mirror-*.yml || true
+          ./hack/generate-workflow.sh
+      - name: Sync
+        env:
+          GH_TOKEN: "${{ secrets.GH_TOKEN }}" # Permission to operate Workflows is required
+        run: |
+          git add .github/workflows/mirror-*.yml && git commit -m "Generate Workflow YAML" && {
+            git config --global user.name "bot"
+            SOURCE=$(git remote get-url origin | sed -E 's#git@(.+):(.+)#https://\1/\2#g' | sed "s#https://github.com#https://bot:${GH_TOKEN}@github.com#g")
+            git remote add upstream "${SOURCE}"
+            git push upstream main
+          }

hack/generate-workflow.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+cat ./mirror.txt | while read line; do
+  line="${line// /}"
+  if [[ "${line}" == "#"* ]] || [[ "${line}" == "" ]]; then
+    continue
+  fi
+
+  host="${line%%/*}"
+  image="${line#*/}"
+  workflow=".github/workflows/mirror-${host//./-}-${image//\//-}.yml"
+
+  cat <<EOF >"${workflow}"
+name: "Sync ${host}/${image}"
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "0 0 * * *"
+
+jobs:
+  sync-image:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Sync
+      env:
+        CREDS: "\${{ secrets.CREDS }}"
+        MIRROR: "\${{ secrets.MIRROR }}"
+      run: |
+        docker run --rm -it ananace/skopeo \\
+          sync --src docker --dest docker --dest-tls-verify=false --dest-creds "\${CREDS}" -f oci \\
+          "${host}/${image}" "\${MIRROR}/${image}"
+
+EOF
+
+done