Automate Ubuntu base image upgrade

See spring-projectsgh-20355

ci/pipeline.yml

@@ -163,6 +163,21 @@ jobs:
         GITHUB_USERNAME: ((github-username))
         JDK_VERSION: java11
       image: spring-boot-ci-image
+- name: detect-ubuntu-image-updates
+  plan:
+  - get: git-repo
+  - get: every-wednesday
+    trigger: true
+  - get: spring-boot-ci-image
+  - do:
+    - task: detect-ubuntu-image-updates
+      file: git-repo/ci/tasks/detect-ubuntu-image-updates.yml
+      params:
+        GITHUB_REPO: spring-boot
+        GITHUB_ORGANIZATION: spring-projects
+        GITHUB_PASSWORD: ((github-password))
+        GITHUB_USERNAME: ((github-username))
+      image: spring-boot-ci-image
 - name: build
   serial: true
   public: true
@@ -525,6 +540,6 @@ groups:
 - name: "Release"
   jobs: ["stage-milestone", "stage-rc", "stage-release", "promote-milestone", "promote-rc", "promote-release", "sync-to-maven-central"]
 - name: "CI Images"
-  jobs: ["build-spring-boot-ci-images", "detect-jdk-updates"]
+  jobs: ["build-spring-boot-ci-images", "detect-jdk-updates", "detect-ubuntu-image-updates"]
 - name: "Build Pull Requests"
   jobs: ["build-pull-requests"]

ci/scripts/detect-ubuntu-image-updates.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+ISSUE_TITLE="Upgrade Ubuntu version in CI images"
+
+ubuntu="bionic"
+latest=$( curl -s "https://partner-images.canonical.com/core/$ubuntu/current/unpacked/build-info.txt" | awk '{split($0, parts, "="); print parts[2]}' )
+current=$( grep "ubuntu:$ubuntu" git-repo/ci/images/spring-boot-ci-image/Dockerfile | awk '{split($0, parts, "-"); print parts[2]}' )
+
+if [[ $current = $latest ]]; then
+	echo "Already up-to-date"
+	exit 0;
+fi
+
+existing_tasks=$( curl -s https://api.github.com/repos/${GITHUB_ORGANIZATION}/${GITHUB_REPO}/issues\?labels\=type:%20task\&state\=open\&creator\=spring-buildmaster )
+existing_upgrade_issues=$( echo "$existing_tasks" | jq -c --arg TITLE "$ISSUE_TITLE" '.[] | select(.title==$TITLE)' )
+
+if [[ ${existing_upgrade_issues} = "" ]]; then
+	curl \
+	-s \
+	-u ${GITHUB_USERNAME}:${GITHUB_PASSWORD} \
+	-H "Content-type:application/json" \
+	-d "{\"title\":\"${ISSUE_TITLE}\",\"body\": \"Upgrade to ubuntu:${ubuntu}-${latest}\",\"labels\":[\"status: waiting-for-triage\",\"type: task\"]}"  \
+	-f \
+	-X \
+	POST "https://api.github.com/repos/${GITHUB_ORGANIZATION}/${GITHUB_REPO}/issues" > /dev/null || { echo "Failed to create issue" >&2; exit 1; }
+else
+	echo "Issue already exists."
+fi

ci/tasks/detect-ubuntu-image-updates.yml

@@ -0,0 +1,11 @@
+---
+platform: linux
+inputs:
+  - name: git-repo
+params:
+  GITHUB_REPO:
+  GITHUB_ORGANIZATION:
+  GITHUB_PASSWORD:
+  GITHUB_USERNAME:
+run:
+  path: git-repo/ci/scripts/detect-ubuntu-image-updates.sh