Add dev container configuration

To support this the `flask` wrapper will detech whether `SETTINGS_FILE`
is set, and if so assume we're already running within a container.

.devcontainer/devcontainer.json

@@ -0,0 +1,46 @@
+{
+  "name": "EMF Web",
+  // Compose config
+  "dockerComposeFile": "../docker-compose.yml",
+  "service": "app",
+  "workspaceFolder": "/app",
+  "containerEnv": {
+    "EDITOR": "code -w"
+  },
+  // Replace the standard command with a noop to allow exec-ing
+  "overrideCommand": true,
+  // Git complains if user IDs don't match, which they will with a mounted directory
+  "onCreateCommand": "git config --global --add safe.directory /app",
+  // Port forwarding
+  "forwardPorts": [
+    2342,
+    "db:5432"
+  ],
+  "portsAttributes": {
+    "2342": {
+      "label": "Web",
+      "onAutoForward": "silent",
+      "requireLocalPort": false
+    },
+    "db:5432": {
+      "label": "Postgres",
+      "onAutoForward": "silent",
+      "requireLocalPort": false
+    }
+  },
+  // VSCode additions
+  "features": {},
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "dbaeumer.vscode-eslint",
+        "EditorConfig.EditorConfig",
+        "github.vscode-github-actions",
+        "ms-python.python",
+        "ms-python.black-formatter",
+        "ms-python.flake8",
+        "ms-python.mypy-type-checker"
+      ]
+    }
+  }
+}

README.md

@@ -49,6 +49,23 @@ To delete all data and start over fresh you can use `docker compose down`.
 Management commands can be listed and run using the `./flask` command, which
 forwards them to the flask command line within the container.
 
+### Visual Studio Code
+
+If you use Visual Studio Code it should present you with the option to open the
+project in a dev container. If not, run `code .` from your local copy, and ensure
+you have the [Dev Containers extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers) installed.
+
+Reopening in a dev container will start everything via Docker, attach
+your VSCode instance to the application container, install relevant extensions,
+and ensure everything is configured to fit with our standards.
+
+The first time you start the dev container you will need to tell VSCode where to
+find the Poetry virtual environment. You can do this by open the command pallette
+(Cmd-P on macOS devices) and searching for "Python: Select interpreter", the list
+presented should include `website-${randomHash}-py3.11`, which will be annotated
+as "Poetry". Select that, and then any Python tooling and shells will run within
+the appropriate virtualenv.
+
 ### Errors starting the dev server
 
 e.g. `Error: While importing 'dev_server', an ImportError was raised.`

flask

@@ -1,3 +1,7 @@
 #!/usr/bin/env bash
 # Shim to run the Flask admin command within docker
-docker compose exec -e SETTINGS_FILE=./config/development.cfg app poetry run flask "$@"
+if [ -z "${SETTINGS_FILE}" ]; then
+  docker compose exec -e SETTINGS_FILE=./config/development.cfg app poetry run flask "$@"
+else
+  exec poetry run flask "$@"
+fi