From 8af7e687c153422f64e1e6664c03b662fd6d6f3f Mon Sep 17 00:00:00 2001
From: Tom Ward <tomward@fmail.co.uk>
Date: Mon, 25 Sep 2023 16:11:44 +0100
Subject: [PATCH] feat: add GHA workflow to keep track of the Ubuntu image SHA

* This is to workaround the 3mo timeout for GHA scheduled actions on repos with
  no new commits, by automatically creating new commits.
---
 .github/workflows/update-ubuntu-sha.yaml | 33 ++++++++++++++++++++++++
 Justfile                                 | 10 +++++++
 ubuntu:20.04.sha                         |  1 +
 ubuntu:22.04.sha                         |  1 +
 4 files changed, 45 insertions(+)
 create mode 100644 .github/workflows/update-ubuntu-sha.yaml
 create mode 100644 ubuntu:20.04.sha
 create mode 100644 ubuntu:22.04.sha

diff --git a/.github/workflows/update-ubuntu-sha.yaml b/.github/workflows/update-ubuntu-sha.yaml
new file mode 100644
index 0000000..f7d9aef
--- /dev/null
+++ b/.github/workflows/update-ubuntu-sha.yaml
@@ -0,0 +1,33 @@
+name: Update SHA of latest ubuntu images
+# This is to workaround the 3mo timeout for GHA scheduled actions on repos with 
+# no new commits, by automatically creating new commits.
+on:
+  schedule:
+    # check for a new ubuntu image every week at 04:17am on mondays
+    - cron: "17 04 * * 1"
+  # let us manually trigger a build
+  workflow_dispatch:
+env:
+  BASE_IMAGE_NAME: base-docker
+  ACTION_IMAGE_NAME: base-action
+jobs:
+jobs:
+  update:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@master
+    - uses: extractions/setup-just@69d82fb0233557aec017ef13706851d0694e0f1d
+    - name: update SHAs
+      run: just update-docker-shas
+    - name: Commit file
+      run: |
+        git status
+        git add *.sha
+        if git diff-index --quiet HEAD; then
+          exit
+        fi
+        git config --local user.email "action@github.com"
+        git config --local user.name "GitHub Action"
+        git commit -m "Update base image SHA files"
+        git push origin
diff --git a/Justfile b/Justfile
index dd051bd..a03a4d5 100644
--- a/Justfile
+++ b/Justfile
@@ -24,3 +24,13 @@ test: build
   docker run $RUN_ARGS --rm -v {{justfile_directory()}}:/tests -w /tests $ACTION_IMAGE_NAME:20.04 ./tests.sh
   docker run $RUN_ARGS --rm -v {{justfile_directory()}}:/tests -w /tests $ACTION_IMAGE_NAME:22.04 ./tests.sh
   ./check.sh
+
+# Update the files tracking the SHAs of ubuntu docker image
+update-docker-shas:
+  @just _update-sha "ubuntu:20.04"
+  @just _update-sha "ubuntu:22.04"
+
+_update-sha os:
+  echo {{ os }}
+  docker image pull {{ os }}
+  docker inspect --format='{{{{index .RepoDigests 0}}' {{ os }} > {{ os }}.sha
diff --git a/ubuntu:20.04.sha b/ubuntu:20.04.sha
new file mode 100644
index 0000000..7563a52
--- /dev/null
+++ b/ubuntu:20.04.sha
@@ -0,0 +1 @@
+ubuntu@sha256:33a5cc25d22c45900796a1aca487ad7a7cb09f09ea00b779e3b2026b4fc2faba
diff --git a/ubuntu:22.04.sha b/ubuntu:22.04.sha
new file mode 100644
index 0000000..e052622
--- /dev/null
+++ b/ubuntu:22.04.sha
@@ -0,0 +1 @@
+ubuntu@sha256:aabed3296a3d45cede1dc866a24476c4d7e093aa806263c27ddaadbdce3c1054