attach to remote docker container in visual studio code with user other than root

Question

I'm using VSCode with the Docker extension. I'm connecting to docker on a remote machine through SSH. When I click on a container in the docker extension and do "Attach Visual Studio Code" if the container was started with the root user then it attaches fine. If it was started with a different uid/gid then I get the following. Not that the image has the user and groups setup correctly from the dockerfile.

[4909 ms] 
[4910 ms] Start: Run in container: cat /etc/passwd
[4947 ms] User 33333:45678 not found in /etc/passwd.
[4948 ms] Start: Run in container: test -d /root/.vscode-server
[4982 ms] 
[4982 ms] 
[4982 ms] Exit code 1
[4982 ms] Start: Run in container: test -d /root/.vscode-remote
[5019 ms] 
[5019 ms] 
[5019 ms] Exit code 1
[5019 ms] Start: Run in container: set -o noclobber ; mkdir -p '/root/.vscode-server/data/Machine' && { > '/root/.vscode-server/data/Machine/.writeMachineSettingsMarker' ; } 2> /dev/null
[5057 ms] 
[5057 ms] mkdir: cannot create directory ‘/root’: Permission denied
[5058 ms] Exit code 1
[5059 ms] Start: Run in container: test -d /root/.vscode-server/bin/d5e9aa0227e057a60c82568bf31c04730dc15dcd
[5095 ms] 
[5096 ms] 
[5096 ms] Exit code 1
[5096 ms] Installing VS Code Server for commit d5e9aa0227e057a60c82568bf31c04730dc15dcd
[5096 ms] Start: Run in container: mkdir -p /root/.vscode-server/bin/d5e9aa0227e057a60c82568bf31c04730dc15dcd_1595365126276
[5133 ms] 
[5134 ms] mkdir: cannot create directory ‘/root’: Permission denied
[5134 ms] Exit code 1

Answer 1

I solved a similar problem in a fairly brute-force way. I added a specific user directly in the Dockerfile (first defining the group they belong to):

RUN groupadd --gid $GID $GROUPNAME
RUN useradd --uid $UID --gid $GID -m $USERNAME

and then in the docker-compose added the following line under all services I wanted to log in to with that specific UID/GID:

user: $USERNAME

For docker-compose you will need first to export the username explicitely before building your containers:

export USERNAME="Max Mustermann"

(unless, of course, you're using your own local username, in which case just writing user: $USER without exporting anything is enough.

The reason for adding the user in the Dockerfile is that you want to have user data listed in /etc/passwd so that VSCode can pick them up. If you don't have access to Dockerfile you can also make a small shell script that is going to attach to the container as the default (root) user and add the desired UID/GID subsequently.

After this VSCode automatically attached to the container as that specific user.