gistfile1.txt

Random ports used by webpack-serve despite ports configured.

repo: https://github.com/airtonix/netlify-cms-widget-relations

It's also caused by the fact that you might have `onchange` wrapping your callto `webpack-serve`, which 
leads to `onchange` sending SIGTERM instead of SIGINT to the childprocess it wraps.

The result is that `webpack-serve` remains running, thus keeps the intially configured port and the 
next process uses a random port.

In a bare metal naive scenario this might not be a problem. But in docker, we expect that the process 
will only use the port we configure.

Basically my scenario is that I use docker to make the development environment portable.

1. I wrap `webpack-serve` with `onchange`.
2. when certain files that are only read at bootup by webpack change, `onchange` runs it again

```
$ npm run dev

> [email protected] dev C:\Users\zenobius\Projects\Mine\netlify-cms-widget-relations
> npm run docker:serve -- as_server npm run container:dev:watch


> [email protected] docker:serve C:\Users\zenobius\Projects\Mine\netlify-cms-widget-relations
> npm run docker:run -- --service-ports "as_server" "npm" "run" "container:dev:watch"


> [email protected] docker:run C:\Users\zenobius\Projects\Mine\netlify-cms-widget-relations
> docker-compose run --rm "--service-ports" "as_server" "npm" "run" "container:dev:watch"

.start
.exec npm run container:dev:watch

> [email protected] container:dev:watch /app
> npx onchange "./package.json" "./webpack_config/**/*" -v -p -i -- npm run container:dev

onchange: watching ./package.json, ./webpack_config/**/*
onchange: executing command "npm run container:dev"

> [email protected] container:dev /app
> NODE_ENV=develop webpack-serve --config=./webpack_config --port=$PORT --host=$HOST

ℹ ｢hot｣: webpack: Compiling...
ℹ ｢hot｣: WebSocket Server Listening at 0.0.0.0:8081
[04:48:37] ℹ ｢serve｣: Project is running at http://0.0.0.0:3000
ℹ ｢hot｣: webpack: Compiling Done
ℹ ｢wdm｣: Hash: 9923769365c6eb286c9a
Version: webpack 4.6.0
Time: 13147ms
Built at: 2018-08-11 04:48:39
     Asset       Size  Chunks             Chunk Names
   main.js   5.08 MiB    main  [emitted]  main
index.html  180 bytes          [emitted]

// snip lots of build info

onchange: change to package.json
onchange: killing command 31 and restarting
onchange: command completed with code 0
onchange: executing command "npm run container:dev"
```

Regardless of what I tell `onchange` to send as the kill signal `webpack-serve` continues to use a random port next time around.

```
//package.json
...

  "serve": {
    "hmr": true,
    "hotClient": {
      "host": "localhost"
    },
    "dev": {
      "watchOptions": {
        "poll": 300
      }
    },
    "clipboard": false,
    "logTime": true,
    "logLevel": "info",
    "openPath": "/#/collections/test/entries/test"
  },
  "scripts": {
    "[ workstation/container: commands ]": "",
    "container:dev:watch": "npx onchange \"./package.json\" \"./webpack_config/**/*\" -v -p -i -- npm run container:dev",
    "container:dev": "NODE_ENV=develop webpack-serve --config=./webpack_config --port=$PORT --host=$HOST",
    "container:demo": "NODE_ENV=production webpack --config=./webpack_config --display errors-only --devtool source-map",
    "container:prod": "NODE_ENV=production webpack",

    "[ workstation: docker commands ]": "",
    "docker:serve": "npm run docker:run -- --service-ports",
    "docker:run": "docker-compose run --rm",
    "docker:build": "docker-compose -f ./docker-compose--build.yml build image",
    "docker:shell": "npm run docker:run -- as_builder /bin/sh",

    "[ workstation: dev commands ]": "",
    "dev": "npm run docker:serve -- as_server npm run container:dev:watch",
    "prod": "npm run docker:run -- as_builder npm run container:prod",
    "prepublishOnly": "npm run docker:run -- as_builder npm run container:prod"
  }
...

```

```
# Dockerfile
FROM node:8.9.0-alpine as builder

WORKDIR /build

RUN apk add --no-cache \
  autoconf \
  automake \
  ca-certificates \
  curl \
  g++ \
  gcc \
  git \
  jpeg-dev \
  jq \
  make \
  nasm \
  openssh \
  openssl \
  python \
  run-parts \
  zlib-dev \
  && update-ca-certificates

RUN npm install -g node-gyp

COPY ./package.json .
COPY ./yarn.lock .
RUN yarn install


FROM node:8.9.0-alpine

WORKDIR /app

COPY --from=builder /build/node_modules /app/node_modules
COPY entrypoint.sh /entrypoint.sh
RUN chmod +x /entrypoint.sh

ENTRYPOINT ["/entrypoint.sh"]
CMD [ "npm", "run", "container:start" ]


```

```
# docker-compose.yml
version: "2.0"

services:

  image:
    image: airtonix/dev-${npm_package_name}:${npm_package_version}

  as_builder:
    extends: {service: "image"}
    volumes:
      - "./:/app/"
      - "/app/node_modules"

  as_server:
    extends: {service: "as_builder"}
    environment:
      - HOST=0.0.0.0
      - PORT=3000
    ports:
      - "3000:3000"
      - "8081:8081"

```

```
//docker-compose--build.yml
version: "2.0"

services:

  image:
    build: .
    image: airtonix/dev-${npm_package_name}:${npm_package_version}

```