feat: add Docker build (#41187)

* feat(docker): build and use client and api images

* feat: always use .env

dotenv fails without throwing if the .env file is missing and never
overwrites variables if they already exist. As such, we can use it in
build pipelines.

* fix: remove quotes from env vars

dotenv normalises quoted and unquoted strings (X=x, X='x' and
X="x") all become the same .env object {X: 'x'}. However, Docker's
env_file does not (the three cases are distinct).  As a result, we
should use unquoted strings for consistency.

* fix: provide custom warning when .env is missing

* feat(docker): include client-config

* fix(docker): remove build packages from api image

* fix(docker): run script from correct dir

* fix(docker): correct permissions and dests

* fix(docker): consolidate run steps

This is standard practice, but did not have a noticable affect on the
image size

* fix(docker): clean the npm cache

Prior to this step the image was 1.11GB uncompressed and we got a modest
saving, 1.09GB after.

* refactor(docker): regexless COPY directives

* feat(docker): use alpine

This shrinks the image down to 259MB

* fix(docker): update build scripts

* fix: correct the server Dockerfile RUNs

* DEBUG: expose mysql port for seeding

* chore: update client Dockerfile's node versions

* fix: remove executable permissions from index.js

It's not a cli, so I don't think it needs to be executable.

* chore: update node and remove stale comments

* feat: use ENTRYPOINT + CMD to allow runtime config

* fix: add CURRICULUM_LOCALE arg

* feat: allow client port configuration

* feat: allow api port to be configured

* refactor: use unique variable names for ports

* fix: add default CLIENT_PORT

* refactor: clean up

client.Dockerfile

@@ -0,0 +1,40 @@
+FROM node:14.16.1-buster AS builder
+
+# this is a bit clunky, perhaps there's a more concise way of passing in build
+# arguments
+ARG FREECODECAMP_NODE_ENV
+ARG HOME_LOCATION
+ARG API_LOCATION
+ARG FORUM_LOCATION
+ARG NEWS_LOCATION
+ARG CLIENT_LOCALE
+ARG CURRICULUM_LOCALE
+ARG STRIPE_PUBLIC_KEY
+ARG ALGOLIA_APP_ID
+ARG ALGOLIA_API_KEY
+ARG PAYPAL_CLIENT_ID
+ARG DEPLOYMENT_ENV
+ARG SHOW_UPCOMING_CHANGES
+
+# node images create a non-root user that we can use
+USER node
+WORKDIR /home/node/build
+COPY --chown=node:node . .
+RUN npm ci
+# we don't need to separately run ensure-env, since it gets called as part of
+# build:client
+RUN npm run build:client
+
+WORKDIR /home/node/config
+RUN git clone https://github.com/freeCodeCamp/client-config.git client
+
+FROM node:14.16.1-alpine
+RUN npm i -g serve
+USER node
+WORKDIR /home/node
+COPY --from=builder /home/node/build/client/public/ client/public
+COPY --from=builder /home/node/config/client/serve.json client
+COPY --from=builder /home/node/config/client/www/ client
+
+ENTRYPOINT ["serve", "-c", "../serve.json", "client/public"]
+CMD ["-l", "8000"]