Rework devcontainer to use proxygen server

This means that `hhvm` is the actual docker command; the bad news is that if
hhvm crashes, the container goes down.

I'm doing this anyway as there doesn't appear to be support in
devcontainer.json for a separate long-running command - only via docker
compose, which:

- feels like overkill
- appears not to support devcontainer variables like
  containerWorkspaceFolder; this means that it can't work with GitHub
  codespaces, as the `workspaceMount` devcontainer.json option is not
  supported on codespaces

The lack of support for `workspaceMount` is also why there's the fun
messing around with symlinking /var/www and configuration files.

.deploy/built-site.Dockerfile

@@ -3,7 +3,6 @@
 FROM hhvm/hhvm:4.134-latest
 ARG DOCKER_BUILD_ENV=prod
 ENV TZ UTC
-ENV DEBIAN_FRONTEND noninteractive
 ENV LANG en_US.UTF-8
 ENV LANGUAGE en_US:en
 ENV LC_ALL en_US.UTF-8

.deploy/init.sh

@@ -7,13 +7,15 @@ if [ ! -e /docker_build ]; then
   exit 1
 fi
 
+export DEBIAN_FRONTEND=noninteractive
+
 echo "** Installing apt dependencies"
 # This is done by the dockerfile, but the intermediate issue can be cached, so do
 # it again here.
 apt-get clean
 apt-get update -y
 
-apt-get install -y ruby php-cli zip unzip locales
+LC_ALL=C apt-get install -y ruby php-cli zip unzip locales
 
 echo "** Updating locales"
 locale-gen en_US.UTF-8

.devcontainer/Dockerfile

@@ -0,0 +1,7 @@
+FROM hhvm/hhvm-proxygen:4.134-latest
+
+ARG WORKSPACE
+
+RUN rm -rf /var/www; ln -s ${WORKSPACE} /var/www
+RUN ln -sf /var/www/hhvm.dev.ini /etc/hhvm/site.ini
+RUN touch /docker_build

.devcontainer.json → .devcontainer/devcontainer.json

@@ -4,7 +4,16 @@
   "runArgs": [
     "--init"
   ],
-  "image": "hhvm/hhvm:4.134-latest",
+  "build": {
+    "dockerfile": "Dockerfile",
+    "args": {
+      "WORKSPACE": "${containerWorkspaceFolder}"
+    }
+  },
+  "runArgs": [
+    "--env", "LC_ALL=C"
+  ],
+  "overrideCommand": false,
 
   // Set *default* container specific settings.json values on container create.
   "settings": {
@@ -19,12 +28,7 @@
 	"terminal.integrated.defaultProfile.linux": "bash"
 },
 
-  // Add the IDs of extensions you want installed when the container is created.
-  "extensions": [
-	"pranayagarwal.vscode-hack",
-],
-
-  "postCreateCommand": "touch /docker_build; .deploy/init.sh",
-  "postStartCommand": "cd public; hhvm -m server -p 8080 -vServer.AllowRunAsRoot=1 -c ../hhvm.dev.ini",
-  "forwardPorts": [	8080 ]
+  "extensions": [	"pranayagarwal.vscode-hack" ],
+  "forwardPorts": [	80 ],
+  "postCreateCommand": ".deploy/init.sh"
 }

src/build/UpdateTagsCLI.hack

@@ -167,7 +167,7 @@ final class UpdateTagsCLI extends CLIBase {
 
     await $stdout->writeAllAsync(" - updating Dockerfiles\n");
     $dockerfiles = \glob(LocalConfig::ROOT.'/.deploy/*.Dockerfile');
-    $dockerfiles[] = LocalConfig::ROOT.'/.devcontainer.json';
+    $dockerfiles[] = LocalConfig::ROOT.'/.devcontainer/Dockerfile';
 
     foreach ($dockerfiles as $path) {
       \file_get_contents($path)