ci: remove ubuntu 18.04 image (#980)

* ci: remove Ubuntu 18.04 runner

Co-authored-by: toast-gear <toast-gear@users.noreply.github.com>

.github/renovate.json5

@@ -13,8 +13,7 @@
     {
       // use https://github.com/actions/runner/releases
       "fileMatch": [
-        ".github/workflows/ubuntu-18-04-runners.yml",
-        ".github/workflows/ubuntu-20-04-runners.yml"
+        ".github/workflows/runners.yml"
         ],
       "matchStrings": ["RUNNER_VERSION: +(?<currentValue>.*?)\\n"],
       "depNameTemplate": "actions/runner",

.github/workflows/runners.yml

@@ -1,4 +1,4 @@
-name: Ubuntu 20.04 Runners
+name: Runners
 
 on:
   pull_request:
@@ -11,9 +11,8 @@ on:
       - 'master'
     paths:
       - 'runner/**'
-      - .github/workflows/ubuntu-20-04-runners.yml
+      - .github/workflows/runners.yml
       - '!**.md'
-      - '!runner/Dockerfile.ubuntu.1804'
 
 env:
   RUNNER_VERSION: 2.285.0
@@ -23,15 +22,17 @@ env:
 jobs:
   build:
     runs-on: ubuntu-latest
-    name: Build ${{ matrix.name }}-ubuntu-${{ matrix.os-version }}
+    name: Build ${{ matrix.name }}-${{ matrix.os-name }}-${{ matrix.os-version }}
     strategy:
       fail-fast: false
       matrix:
         include:
           - name: actions-runner
+            os-name: ubuntu
             os-version: 20.04
             dockerfile: Dockerfile
           - name: actions-runner-dind
+            os-name: ubuntu
             os-version: 20.04
             dockerfile: Dockerfile.dindrunner
 
@@ -57,8 +58,8 @@ jobs:
             RUNNER_VERSION=${{ env.RUNNER_VERSION }}
             DOCKER_VERSION=${{ env.DOCKER_VERSION }}
           tags: |
-            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-ubuntu-${{ matrix.os-version }}
-            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-ubuntu-${{ matrix.os-version }}-${{ steps.vars.outputs.sha_short }}
+            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-${{ matrix.os-name }}-${{ matrix.os-version }}
+            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-${{ matrix.os-name }}-${{ matrix.os-version }}-${{ steps.vars.outputs.sha_short }}
             ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:latest
           cache-from: type=gha
           cache-to: type=gha,mode=max

.github/workflows/ubuntu-18-04-runners.yml

@@ -1,61 +0,0 @@
-name: Ubuntu 18.04 Runners
-
-on:
-  pull_request:
-    types: 
-      - opened
-      - synchronize
-      - reopened
-      - closed
-    branches:
-      - 'master'
-    paths:
-      - 'runner/**'
-      - .github/workflows/ubuntu-18-04-runners.yml
-      - '!**.md'
-      - '!runner/Dockerfile'
-      - '!runner/Dockerfile.dindrunner'
-
-env:
-  RUNNER_VERSION: 2.284.0
-  DOCKER_VERSION: 20.10.8
-  DOCKERHUB_USERNAME: summerwind
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    name: Build ${{ matrix.name }}-ubuntu-${{ matrix.os-version }}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - name: actions-runner
-            os-version: 18.04
-            dockerfile: Dockerfile.ubuntu.1804
-
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v2
-
-      - name: Setup Docker Environment
-        id: vars
-        uses: ./.github/actions/setup-docker-environment
-        with: 
-          username: ${{ secrets.DOCKER_USER }}
-          password: ${{ secrets.DOCKER_ACCESS_TOKEN }}
-
-      - name: Build and Push Versioned Tags
-        uses: docker/build-push-action@v2
-        with:
-          context: ./runner
-          file: ./runner/${{ matrix.dockerfile }}
-          platforms: linux/amd64,linux/arm64
-          push: ${{ github.ref == 'master' && github.event.pull_request.merged == true }}
-          build-args: |
-            RUNNER_VERSION=${{ env.RUNNER_VERSION }}
-            DOCKER_VERSION=${{ env.DOCKER_VERSION }}
-          tags: |
-            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-ubuntu-${{ matrix.os-version }}
-            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-ubuntu-${{ matrix.os-version }}-${{ steps.vars.outputs.sha_short }}
-          cache-from: type=gha
-          cache-to: type=gha,mode=max

README.md

@@ -1215,7 +1215,7 @@ The project supports being deployed on the various cloud Kubernetes platforms (e
 **Bundled Software**<br />
 The GitHub hosted runners include a large amount of pre-installed software packages. GitHub maintain a list in README files at <https://github.com/actions/virtual-environments/tree/main/images/linux>
 
-This solution maintains a few runner images with `latest` aligning with GitHub's Ubuntu version. Older images are maintained whilst GitHub also provides them as an option. These images do not contain all of the software installed on the GitHub runners. It contains the following subset of packages from the GitHub runners:
+This solution maintains a few runner images with `latest` aligning with GitHub's Ubuntu version, these images do not contain all of the software installed on the GitHub runners. The images contain the following subset of packages from the GitHub runners:
 
 - Basic CLI packages
 - git