Enable docker cache (#39)

* enable docker cache

* env lowercase

* fix space

* action/checkout version4

* change name repo

.github/workflows/tests.yml

@@ -2,15 +2,33 @@ name: tests
 
 on: [push, pull_request]
 
+env:
+  REGISTRY: ghcr.io/commaai
+  BUILD: docker buildx build --pull --load --cache-to type=inline --cache-from $REGISTRY/rednose:latest -t rednose -f Dockerfile .
+  RUN: docker run rednose bash -c
+
 jobs:
   test:
     runs-on: ubuntu-20.04
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Build docker image
-      run: docker build -t rednose .
+      run: eval ${{ env.BUILD }}
     - name: Static analysis
-      run: |
-        docker run rednose bash -c "git init && git add -A && pre-commit run --all"
+      run: ${{ env.RUN }} "git init && git add -A && pre-commit run --all"
     - name: Unit Tests
-      run: docker run rednose bash -c "cd /project/examples; python -m unittest discover"
+      run: ${{ env.RUN }} "cd /project/examples; python -m unittest discover"
+
+  docker_push:
+    name: docker push
+    runs-on: ubuntu-20.04
+    if: github.ref == 'refs/heads/master' && github.event_name != 'pull_request' && github.repository == 'commaai/rednose'
+    steps:
+    - uses: actions/checkout@v4
+    - name: Build Docker image
+      run: eval ${{ env.BUILD }}
+    - name: Push to dockerhub
+      run: |
+        docker login ghcr.io -u ${{ github.actor }} -p ${{ secrets.GITHUB_TOKEN }}
+        docker tag rednose ${{ env.REGISTRY }}/rednose:latest
+        docker push ${{ env.REGISTRY }}/rednose:latest