Streamline dev container workflow (#2014)

ci/dev/image/Dockerfile

-FROM node:12
-
-RUN apt-get update && apt-get install -y \
-    curl \
-    iproute2 \
-    vim \
-    iptables \
-    net-tools \
-    libsecret-1-dev \
-    libx11-dev \
-    libxkbfile-dev
-
-CMD ["/bin/bash"]

ci/dev/image/exec.sh

 #!/usr/bin/env bash
 set -euo pipefail
 
-# Opens an interactive bash session inside of a docker container
-# for improved isolation during development.
-# If the container exists it is restarted if necessary, then reused.
-
 main() {
-  cd "$(dirname "${0}")/../../.."
-
-  local container_name=code-server-dev
-
-  if docker inspect $container_name &> /dev/null; then
-    echo "-- Starting container"
-    docker start "$container_name" > /dev/null
-
-    enter
-    exit 0
-  fi
-
-  build
-  run
-  enter
-}
-
-enter() {
-  echo "--- Entering $container_name"
-  docker exec -it "$container_name" /bin/bash
-}
+  cd "$(dirname "$0")/../../.."
+  source ./ci/lib.sh
 
-run() {
-  echo "--- Spawning $container_name"
   docker run \
     -it \
-    --name $container_name \
-    "-v=$PWD:/code-server" \
-    "-w=/code-server" \
-    "-p=127.0.0.1:8080:8080" \
-    $(if [[ -t 0 ]]; then echo -it; fi) \
-    "$container_name"
+    --rm \
+    -v "$PWD:/src" \
+    -w /src \
+    -p 127.0.0.1:8080:8080 \
+    "$(docker_build ./ci/images/debian8)" \
+    "$@"
 }
 
-build() {
-  echo "--- Building $container_name"
-  docker build -t $container_name ./ci/dev/image > /dev/null
+docker_build() {
+  docker build "$@" >&2
+  docker build -q "$@"
 }
 
 main "$@"

doc/CONTRIBUTING.md

@@ -46,14 +46,12 @@ yarn watch
 To develop inside of an isolated docker container:
 
 ```shell
-./ci/dev/image/exec.sh
-
-root@12345:/code-server# yarn
-root@12345:/code-server# yarn vscode
-root@12345:/code-server# yarn watch
+./ci/dev/image/exec.sh yarn
+./ci/dev/image/exec.sh yarn vscode
+./ci/dev/image/exec.sh yarn watch
 ```
 
-Any changes made to the source will be live reloaded.
+`yarn watch` will live reload changes to the source.
 
 If changes are made to the patch and you've built previously you must manually
 reset VS Code then run `yarn vscode:patch`.
@@ -78,7 +76,7 @@ node .
 Build release packages (make sure you run `./ci/steps/release.sh` first):
 
 ```
-./ci/steps/release-packages.sh
+./ci/dev/image/exec.sh ./ci/steps/release-packages.sh
 # The standalone release is in ./release-standalone
 # .deb, .rpm and the standalone archive are in ./release-packages
 ```