Persist nix store

.devcontainer/Dockerfile

@@ -30,5 +30,15 @@ RUN curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/
 # Now use devbox as global package manager
 RUN echo 'eval "$(devbox global shellenv --preserve-path-stack -r)" && hash -r' >> ~/.bashrc
 
+# Backup of the nix-store
+RUN cp -a /nix/store /nix-store-backup
+
+# Add start script
+COPY scripts/start.sh /usr/local/bin/start.sh
+RUN chmod +x /usr/local/bin/start.sh
+
+# Set start script as entrypoint
+ENTRYPOINT ["/usr/local/bin/start.sh"]
+
 WORKDIR /workspace
 CMD ["sh"]

.devcontainer/docker-compose.yml

@@ -16,6 +16,12 @@ services:
       - ../devbox.lock:/root/.local/share/devbox/global/default/devbox.lock
       # mount workspace
       - ../src:/workspace
+      # persist nix-store
+      - nix-store:/nix
     # vscode needs a running container, so we make its shell interactive
     stdin_open: true # docker run -i
-    tty: true        # docker run -t
+    tty: true        # docker run -t
+
+volumes:
+  nix-store:
+    external: true

.devcontainer/scripts/start.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+# Checks if /nix/store is empty
+if [ -z "$(ls -A /nix/store)" ]; then
+  echo "Nix store volume is empty. Copying pre-filled store from image."
+  cp -a /nix-store-backup/. /nix/store/
+else
+  echo "Nix store volume is not empty. Skipping copy."
+fi
+
+# Start the normal container process
+exec "$@"