Switch to mamba devcontainer to fix issue with conda ignoring versions

Author: stefmolin

.devcontainer/Dockerfile

@@ -1,9 +1,18 @@
-ARG VARIANT=2
-FROM mcr.microsoft.com/devcontainers/universal:${VARIANT}
+# https://github.com/microsoft/vscode-dev-containers/blob/main/containers/python-3-miniconda/.devcontainer/base.Dockerfile
+ARG VARIANT=3
+FROM mcr.microsoft.com/vscode/devcontainers/miniconda:${VARIANT}
+
+# Install mamba for faster install
+ENV MAMBA_EXE="/opt/mambaforge/bin/mamba"
+RUN cd /tmp \
+    && curl -L -O "https://github.com/conda-forge/miniforge/releases/latest/download/Mambaforge-$(uname)-$(uname -m).sh" \
+    && sudo bash Mambaforge-$(uname)-$(uname -m).sh -b -p /opt/mambaforge
 
 # Create the conda environment
 COPY environment.yml /tmp/conda-tmp/
-RUN conda env create --file /tmp/conda-tmp/environment.yml
+RUN $MAMBA_EXE env create --file /tmp/conda-tmp/environment.yml --prefix /home/vscode/.conda/envs/pandas_workshop \
+    && $MAMBA_EXE init
 
 # Update PATH for Jupyter editing option
-ENV PATH="/opt/conda/envs/pandas_workshop/bin:${PATH}"
+ENV PATH="/home/vscode/.conda/envs/pandas_workshop/bin:${PATH}"
+ENV PROJ_LIB="/home/vscode/.conda/envs/pandas_workshop/share/proj"

.devcontainer/devcontainer.json

@@ -26,7 +26,7 @@
 		"vscode": {
 			// Set *default* container specific settings.json values on container create.
 			"settings": {
-				"python.defaultInterpreterPath": "/opt/conda/envs/pandas_workshop"
+				"python.defaultInterpreterPath": "/home/vscode/.conda/envs/pandas_workshop"
 			},
 
 			// Add the IDs of extensions you want installed when the container is created.