chore: Optimize docker build oss (#3951)

## About the changes
Reduce the build time of OSS docker image from
[~30m](https://github.com/Unleash/unleash/actions/workflows/docker_publish.yaml)
to [under
15m](https://github.com/Unleash/unleash/actions/runs/5222180536/jobs/9427342758)

1. Build frontend outside docker multiplatform.
2. Allow `frontend/build` to be copied to the image by removing this
from `.dockerignore`
3. Run with `--ignore-scripts` to avoid building the frontend on the
`prepare` script, but this requires us to run all the prepare scripts
manually (except the frontend build).
 
**Note:** we need to build frontend in the `prepare` script to be able
to have source code dependencies

## Manual Testing
Manually downloaded from
https://hub.docker.com/r/unleashorg/unleash-server/tags?page=1 and
compared both `unleash` folders from main and the version built with the
new process
https://github.com/Unleash/unleash/actions/runs/5223078089/jobs/9429430190#step:5:48

![Screenshot from 2023-06-10
21-11-33](https://github.com/Unleash/unleash/assets/455064/60a41739-904d-480d-8d80-bf17b7a70432)

No major difference was spotted (only expected changes due to
development done in main)

**Command used to extract the contents:** 

```
cd /tmp
mkdir main && cd main
docker pull unleashorg/unleash-server:main-edge-18-alpine
docker export $(docker create unleashorg/unleash-server:main-edge-18-alpine) > container.tar && tar xvf container.tar
mkdir ../new-process && cd ../new-process
docker pull unleashorg/unleash-server:sha-ccac902-18-alpine
docker export $(docker create unleashorg/unleash-server:sha-ccac902-18-alpine) > container.tar && tar xvf container.tar
meld ./unleash ../main/unleash
```

.dockerignore

@@ -11,4 +11,3 @@
 !README.md
 !frontend
 frontend/node_modules
-frontend/build

.github/workflows/docker_publish.yaml

@@ -6,6 +6,12 @@ on:
       - main
     tags:
       - 'v*'
+  workflow_dispatch:
+    inputs:
+      ignore-push:
+        description: 'Ignore push to dockerhub. If not set the image will be pushed with the sha of the commit as tag'
+        required: false
+        type: boolean
 
 jobs:
   build:
@@ -33,16 +39,23 @@ jobs:
             type=semver,pattern={{ major }},enable=${{ startsWith(github.ref, 'refs/tags/v') }}
             # only enabled in main:
             type=edge,prefix=main-,suffix=-${{ matrix.version }},enable=${{ github.ref == 'refs/heads/main' }}
+            # only enabled on workflow_dispatch:
+            type=sha,suffix=-${{ matrix.version }},enable=${{ github.event_name == 'workflow_dispatch' }}
       - name: Login to docker hub
         uses: docker/login-action@v2
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - name: Build frontend
+        run: |
+          yarn --cwd ./frontend install
+          yarn build:frontend
       - name: Build tag and push image to Docker hub
         uses: docker/build-push-action@v3
         with:
+          context: .
           platforms: linux/amd64,linux/arm64
-          push: true
+          push: ${{ github.event_name != 'workflow_dispatch' || github.event.inputs.ignore-push != 'true' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           build-args: NODE_VERSION=${{ matrix.version }}

Dockerfile

@@ -8,9 +8,10 @@ COPY . /unleash
 
 RUN yarn config set network-timeout 300000
 
-RUN yarn install --frozen-lockfile && yarn local:package
+RUN yarn install --frozen-lockfile --ignore-scripts && yarn prepare:backend && yarn local:package
 
-RUN mkdir /unleash/build/frontend && cp -r /unleash/frontend/build /unleash/build/frontend/build
+# frontend/build should already exist (it needs to be built in the local filesystem
+RUN mkdir -p /unleash/build/frontend && mv /unleash/frontend/build /unleash/build/frontend/build
 
 WORKDIR /unleash/docker
 

package.json

@@ -39,6 +39,7 @@
     "dev:frontend": "wait-on tcp:4242 && yarn --cwd ./frontend run dev",
     "dev": "concurrently \"yarn:dev:backend\" \"yarn:dev:frontend\"",
     "prepare": "node scripts/husky-install && yarn --cwd ./frontend install && if [ ! -d ./dist ]; then yarn build; fi",
+    "prepare:backend": "concurrently \"yarn:copy-templates\" \"yarn:build:backend\"",
     "prestart:dev": "yarn run clean",
     "start:dev": "TZ=UTC NODE_ENV=development tsc-watch --strictNullChecks false --onSuccess \"node dist/server-dev.js\"",
     "db-migrate": "db-migrate --migrations-dir ./src/migrations",