Test: Extensions are cached

[chrmarti]

Refs: #2227

• windows @RMacfarlane
• anyOS @weinand

Complexity: 3

Create Issue

---

• Setup a devcontainer (see any of the instructions).
• Add a list of extensions to its devcontainer.json (or the attach config, if you are using the attach case). (E.g., using 'Add to devcontainer.json' from the Extensions viewlet's context menu.)
• Rebuild the container and verify the extensions are installed.
• Enable 'trace' logging in the settings:
  
• Rebuild the container and verify the extensions are copied over from the local cache.
  • Remote-Containers: Show Log and search for extensions cache. One of these entries should say that it copies the extensions to the remote.

If you are using a single container:

• Add "mounts": ["type=volume,src=extensionsCache,target=/home/node/.vscode-server-insiders/extensionsCache"] to your devcontainer.json.
• Verify that rebuilding the container now copies the extensions to the container only once, after that the copies on the mounted volume are used. (Again check the log with 'trace' level enabled.)
• Note: If you are running the container as another user than root, you will need to create the extensionsCache folder in the container with that user as the owner in your Dockerfile first (a Docker limitation). E.g.:

FROM node:12
USER node
RUN mkdir -p /home/node/.vscode-server-insiders/extensionsCache

/fyi @Chuxel Not sure if you want to document the advanced case of mounting a volume (see above).

[weinand]

@chrmarti I'm seeing:

[2016 ms] Extensions cache, copy to remote: andreweinand.mock-debug-0.41.0, eamodio.gitlens-10.2.1

That's the correct log message, right?

After adding the "mounts" definition to the devcontainer.json, "rebuilding" results in this log:
container-log.txt

I still see a "Extensions cache, copy to remote:" in there. Does this mean that the copies from the mounted volume are not used?

[chrmarti]

@weinand That's the right message. And yes "copy to remote" means that the copies from the mounted volume are not used. I realize the "mounts" definition above says /home/node when it would be /root in your case, maybe that's the issue?

[weinand]

@chrmarti after changing the path in the .devcontainer.json from /home/node to /root I see a

[2008 ms] Extensions cache, copy to remote: None

That looks better, right?

[chrmarti]

@weinand Yes, thanks. 👍