chore(build): improve devcontainers setup with poetry (#506)

1. Replaces uses an image directly.
2. Creates a custom image, still based off the original Image.
3. Installs poetry inside the container. This saves the user about 20
seconds every container load.
4. Installs `pre-commit` in the container. Saves more time.
5. Enables `pre-commit`. From inside the container the user cannot
commit without `pre-commit` running.
6. Adds in git autocomplete to the container (see screenshot)
7. Adds in poetry autocomplete to the container (see screenshot)

![devcontainer-completion](https://github.com/testcontainers/testcontainers-python/assets/1908139/11446f78-4fbf-4d08-a997-043ae1632919)

---------

Co-authored-by: bstrausser <[email protected]>
Co-authored-by: David Ankin <[email protected]>
Co-authored-by: Bálint Bartha <[email protected]>

Author: 4 people

.devcontainer/Dockerfile

@@ -0,0 +1,20 @@
+FROM mcr.microsoft.com/devcontainers/python:1-3.11-bookworm
+
+
+RUN \
+    apt update && apt install bash-completion -y && \
+    pip install pre-commit && \
+    curl -sSL https://install.python-poetry.org | POETRY_HOME=/home/vscode/.local python3 -
+
+
+RUN  \
+    echo >> /home/vscode/.bashrc && \
+    # add completions to bashrc
+    # see how ubuntu does it for reference:
+    # https://git.launchpad.net/ubuntu/+source/base-files/tree/share/dot.bashrc
+    # https://stackoverflow.com/a/68566555
+    echo 'if [ -f /etc/bash_completion ] && ! shopt -oq posix; then' >> /home/vscode/.bashrc && \
+    echo '    . /etc/bash_completion' >> /home/vscode/.bashrc && \
+    echo 'fi' >> /home/vscode/.bashrc && \
+    echo >> /home/vscode/.bashrc && \
+    echo '. <(poetry completions)' >> /home/vscode/.bashrc

.devcontainer/commands/post-create-command.sh

@@ -1,5 +1,4 @@
 echo "Running post-create-command.sh"
 
-curl -sSL https://install.python-poetry.org | python3 -
-
+pre-commit install
 poetry install --all-extras

.devcontainer/devcontainer.json

@@ -3,7 +3,13 @@
 {
 	"name": "Python 3",
 	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
-	"image": "mcr.microsoft.com/devcontainers/python:1-3.11-bookworm",
+	"build": {
+		// Path is relative to the devcontainer.json file.
+		// We prebuild the image to get poetry into the image
+		// This saves the user a bit of time, when re-opening containers
+		"dockerfile": "Dockerfile"
+	},
+
 	"features": {
 		"ghcr.io/devcontainers/features/docker-in-docker:2": {
 			"version": "latest",