Dockerfile for the Next.js frontend and Action to build and publish

[jonkafton]

What are the relevant tickets?

Docker container for https://github.com/mitodl/hq/issues/5396
Build and publish for https://github.com/mitodl/hq/issues/5400

In preparation for https://github.com/mitodl/hq/issues/5399

Description (What does it do?)

• Provides the Dockerfile for the Next.js server
• Github Action to build and publish to Docker hub.
  • Currently building for all pushes, but we'll want to limit to the nextjs branch and ultimately the release-candidate and production workflows.
  • Pushes to Dockerhub tagged with the short commit SHA:
    • https://hub.docker.com/r/mitodl/mit-learn-frontend/tags

How can this be tested?

Image can build locally with:

docker build \
  -f frontends/main/Dockerfile \
  --build-arg NEXT_PUBLIC_ORIGIN=http://api.open.odl.local:8062 \
  --build-arg NEXT_PUBLIC_MITOL_API_BASE_URL=http://open.odl.local:8063 \
  --build-arg NEXT_PUBLIC_SITE_NAME="MIT Learn" \
  --build-arg NEXT_PUBLIC_MITOL_SUPPORT_EMAIL=mitlearn-support@mit.edu \
  --build-arg NEXT_PUBLIC_EMBEDLY_KEY= \
  --build-arg NEXT_PUBLIC_MITOL_AXIOS_WITH_CREDENTIALS=true \
  --build-arg NEXT_PUBLIC_CSRF_COOKIE_NAME=csrftoken-local \
  -t mitodl/mit-learn-frontend:latest .

And runs with:

docker run -p 8062:8062 -e PORT=8062 mit-learn-frontend:latest

For deployment we just need to pass the PORT on the environment. The other env vars are public and provided at build time.

Currently using these values for RC (secrets from GitHub Actions):

  ORIGIN: https://next.rc.learn.mit.edu
  MITOL_API_BASE_URL: https://api.rc.learn.mit.edu
  SITE_NAME: MIT Learn
  MITOL_SUPPORT_EMAIL: mitlearn-support@mit.edu
  EMBEDLY_KEY: ${{ secrets.EMBEDLY_KEY_RC }}
  MITOL_AXIOS_WITH_CREDENTIALS: true
  CSRF_COOKIE_NAME: ${{ secrets.CSRF_COOKIE_NAME_RC }}

Assumes that DNS will point to next.rc.learn.mit.edu for the RC deployment.