DEV: Update CI workflows (#104)

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

.github/workflows/plugin-linting.yml

@@ -23,12 +23,10 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: 2.7
-
-      - name: Setup gems
-        run: bundle install --jobs 4
+          bundler-cache: true
 
       - name: Yarn install
-        run: yarn install --dev
+        run: yarn install
 
       - name: ESLint
         run: yarn eslint --ext .js,.js.es6 --no-error-on-unmatched-pattern {test,assets}/javascripts

.github/workflows/plugin-tests.yml

@@ -11,13 +11,14 @@ jobs:
   build:
     name: ${{ matrix.build_type }}
     runs-on: ubuntu-latest
+    container: discourse/discourse_test:release
     timeout-minutes: 60
 
     env:
       DISCOURSE_HOSTNAME: www.example.com
       RUBY_GLOBAL_METHOD_CACHE_SIZE: 131072
       RAILS_ENV: test
-      PGHOST: localhost
+      PGHOST: postgres
       PGUSER: discourse
       PGPASSWORD: discourse
 
@@ -74,29 +75,26 @@ jobs:
           git config --global user.email "ci@ci.invalid"
           git config --global user.name "Discourse CI"
 
-      - name: Setup packages
-        run: |
-          sudo apt-get update
-          sudo apt-get -yqq install postgresql-client libpq-dev gifsicle jpegoptim optipng jhead
-          wget -qO- https://raw.githubusercontent.com/discourse/discourse_docker/master/image/base/install-pngquant | sudo sh
-
-      - name: Update imagemagick
-        if: matrix.build_type == 'backend'
-        run: |
-          wget https://raw.githubusercontent.com/discourse/discourse_docker/master/image/base/install-imagemagick
-          chmod +x install-imagemagick
-          sudo ./install-imagemagick
-
       - name: Setup redis
         uses: shogo82148/actions-setup-redis@v1
         with:
           redis-version: ${{ matrix.redis }}
 
-      - name: Setup ruby
-        uses: ruby/setup-ruby@v1
+      - name: Bundler cache
+        uses: actions/cache@v2
         with:
-          ruby-version: ${{ matrix.ruby }}
-          bundler-cache: true
+          path: vendor/bundle
+          key: ${{ runner.os }}-${{ matrix.ruby }}-gem-${{ hashFiles('**/Gemfile.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-${{ matrix.ruby }}-gem-
+
+      - name: Setup gems
+        run: |
+          bundle config --local path vendor/bundle
+          bundle config --local deployment true
+          bundle config --local without development
+          bundle install --jobs 4
+          bundle clean
 
       - name: Lint English locale
         if: matrix.build_type == 'backend'
@@ -116,7 +114,7 @@ jobs:
             ${{ runner.os }}-${{ matrix.os }}-yarn-
 
       - name: Yarn install
-        run: yarn install --dev
+        run: yarn install
 
       - name: Migrate database
         run: |