Streamline devcontainer (#456)

Update the devcontainer to remove unnecessary code, and update to use a
workspace with a volume mount for improved performance.

.devcontainer/Dockerfile

@@ -1,9 +1,4 @@
 # Docker environment for local development in devcontainer
-FROM docker.io/alpine/helm:3.13.3 as helm
-FROM docker.io/bitnami/kubectl:1.28.5 as kubectl
-FROM ghcr.io/fluxcd/flux-cli:v2.2.1 as flux
-FROM ghcr.io/kyverno/kyverno-cli:v1.10.7 as kyverno
-FROM registry.k8s.io/kustomize/kustomize:v5.3.0 as kustomize
 
 FROM ubuntu:jammy-20231128
 
@@ -17,15 +12,13 @@ RUN apt-get update --fix-missing && \
         git \
         python3-pip
 
-COPY . /src/
-WORKDIR /src/
-RUN pip3 install -r /src/requirements.txt
-RUN pip3 install -e /src/
-
-COPY --from=ghcr.io/fluxcd/flux-cli:v2.2.1              /usr/local/bin/flux              /usr/local/bin/flux
-COPY --from=docker.io/alpine/helm:3.13.3                /usr/bin/helm                    /usr/local/bin/helm
 COPY --from=docker.io/bitnami/kubectl:1.28.5            /opt/bitnami/kubectl/bin/kubectl /usr/local/bin/kubectl
 COPY --from=registry.k8s.io/kustomize/kustomize:v5.3.0  /app/kustomize                   /usr/local/bin/kustomize
 COPY --from=ghcr.io/kyverno/kyverno-cli:v1.10.7         /ko-app/kubectl-kyverno          /usr/local/bin/kyverno
+COPY --from=docker.io/alpine/helm:3.13.3                /usr/bin/helm                    /usr/local/bin/helm
+COPY --from=ghcr.io/fluxcd/flux-cli:v2.2.1              /usr/local/bin/flux              /usr/local/bin/flux
+
+COPY requirements.txt /src/
+RUN pip3 install -r /src/requirements.txt
 
 SHELL ["/bin/bash", "-c"]

.devcontainer/devcontainer.json

@@ -1,9 +1,13 @@
-// For format details, see https://aka.ms/devcontainer.json. For config options, see the
-// README at: https://github.com/devcontainers/templates/tree/main/src/kubernetes-helm
 {
 	"name": "Kubernetes - Local Configuration",
 	"build": {
 		"context": "..",
 		"dockerfile": "./Dockerfile"
-	}
+	},
+	// Creates a local volume where you the developer need to clone the git
+	// repo inside the container. Uses a local volume since this project
+	// relies heavily on local disk performance.
+	"workspaceMount": "source=flux-local,target=/workspaces,type=volume",
+	"workspaceFolder": "/workspaces/",
+	"postCreateCommand": "chown vscode /workspaces",
 }