composes/code-server/README.md

code-server

VS Code in the browser, from Coder's official codercom/code-server image.

The image ships code-server on Debian with git, zsh, curl, sudo and a few editors. The Dockerfile adds build-essential, bubblewrap, zip, unzip, the headers Ruby builds against, the Docker CLI with its Compose and Buildx plugins, and the GitHub CLI, and wraps the entrypoint so it starts in /workspace and coder can use the Docker socket. Language toolchains and other CLIs are installed into home, below.

Toolchains

Only /home/coder and /workspace survive a redeploy, so install toolchains and CLIs into home from the editor's terminal. Each command below was tested in the image. Open a new terminal afterwards so the PATH changes apply.

Official install methods

These follow the project's own documented install, which already targets home.

Node.js, with nvm, the method marked recommended for Linux on the Node.js download page. nvm, Node and global npm packages all live in ~/.nvm:

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.8/install.sh | bash
. "$HOME/.nvm/nvm.sh"
nvm install 24

Python, with uv, from the uv installation guide and Python install guide. uv puts itself in ~/.local/bin and prebuilt Pythons in ~/.local/share/uv/python. python.org itself documents only distro packages and source builds, both of which land outside home:

curl -LsSf https://astral.sh/uv/install.sh | sh
. "$HOME/.local/bin/env"
uv python install 3.13

Ruby, with rbenv and its ruby-build plugin, each cloned with git as their READMEs document (rbenv, ruby-build). Debian's ruby package is 3.3, several releases behind. Rubies are compiled into ~/.rbenv/versions against the headers the Dockerfile installs. rbenv init adds itself to the login shell's startup file, ~/.zprofile:

git clone https://github.com/rbenv/rbenv.git ~/.rbenv
~/.rbenv/bin/rbenv init
eval "$(~/.rbenv/bin/rbenv init - zsh)"
git clone https://github.com/rbenv/ruby-build.git "$(rbenv root)"/plugins/ruby-build
V=$(rbenv install -l 2>/dev/null | grep -E '^[0-9]+\.[0-9]+\.[0-9]+$' | tail -1)
rbenv install "$V" && rbenv global "$V"

To get newer Ruby versions listed, git -C "$(rbenv root)"/plugins/ruby-build pull.

Java, with SDKMAN, from its install guide. SDKMAN and every JDK it installs live in ~/.sdkman; the installer adds itself to ~/.bashrc and ~/.zshrc, and needs the zip and unzip the Dockerfile installs. sdk install java with no version takes SDKMAN's default, the current Temurin LTS:

curl -s "https://get.sdkman.io" | bash
. "$HOME/.sdkman/bin/sdkman-init.sh"
sdk install java

sdk list java shows other vendors and versions, and sdk install gradle or sdk install maven adds a build tool the same way.

Suggested by AI, may not be the optimal way

These use each project's official download, but no official doc covers installing it into home: the location and the latest-version lookup are improvised. Debian's own packages are no alternative, being several releases behind.

Go, from the official tarball on go.dev/dl. go.dev/doc/install extracts it to /usr/local; the tarball runs from any directory, so it goes in ~/.local/go. go install puts tools in ~/go/bin:

V=$(curl -fsSL 'https://go.dev/VERSION?m=text' | head -1)
mkdir -p ~/.local
curl -fsSL "https://go.dev/dl/$V.linux-$(dpkg --print-architecture).tar.gz" | tar -C ~/.local -xzf -
echo 'export PATH="$HOME/.local/go/bin:$HOME/go/bin:$PATH"' >> ~/.bashrc

To upgrade Go, rm -rf ~/.local/go and run the same commands again, without the echo line.

jq, the binary from its releases page, into ~/.local/bin, with no documented location:

mkdir -p ~/.local/bin
echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc
ARCH=$(dpkg --print-architecture)

V=$(curl -fsSLI -o /dev/null -w '%{url_effective}' https://github.com/jqlang/jq/releases/latest | sed 's|.*/||')
curl -fsSL "https://github.com/jqlang/jq/releases/download/$V/jq-linux-$ARCH" -o ~/.local/bin/jq && chmod +x ~/.local/bin/jq

To upgrade it, run the same commands again, without the echo line; the new binary overwrites the old one.

Environment

Variable	Purpose
PASSWORD	Web UI login. Required.
GIT_NAME / GIT_EMAIL	Git author and committer identity
SERVICE_HOSTNAME	Container hostname, and the name the shell prompt shows (also passed as HOST)
CODE_SERVER_APP_NAME	Optional. Name in the title bar and welcome page; defaults to code-server.

Generate a password with openssl rand -base64 24.

The compose file refuses to start without PASSWORD. If it is unset, code-server generates a random password into ~/.config/code-server/config.yaml, which you can only read from inside the container.

The coder user has passwordless sudo, as the image sets it up. Anyone who can log in to the editor is root in the container.

SERVICE_HOSTNAME is used twice: as the container's hostname: and as the HOST variable inside it. Coolify injects HOST=0.0.0.0 into every compose app, and zsh seeds $HOST and the %m/%M prompt escapes from that variable rather than calling gethostname(), so a zsh prompt reads 0. code-server itself never reads HOST; it binds through --bind-addr. bash is unaffected; its \h uses the real hostname.

Docker access

The host's Docker socket is bind-mounted at /var/run/docker.sock. The Dockerfile installs the client only; the daemon is the host's. Containers started through it are siblings on the host, not children, so bind mounts in them resolve against host paths.

The socket belongs to the host's docker group, whose GID differs from host to host and is not exported anywhere a compose file could read it, so a fixed group_add: would break on another host. Instead entrypoint.sh runs first at startup: it reads the GID off the socket, adds coder to a group with that GID (creating docker-host if none exists) and restarts the image's own entrypoint under the new group. docker then works for coder without sudo, in the editor's terminal and in docker exec shells alike. Access to the socket is root on the host, which is accepted here because this is a single-user dev box.

The wrapper keeps the image's USER 1000, so docker exec still opens a shell as coder, and gets root through the image's passwordless sudo. A running process cannot join a group, so it re-execs through sudo -E setpriv --init-groups, which loads the new group; PATH and USER are passed explicitly because sudo resets both. sudo stays as PID 1 and forwards stop signals to code-server. On a container restart coder is already in the group, and the wrapper hands straight to the image's entrypoint. Without a socket mounted it does nothing.

The :ro flag is not a security boundary. It marks the socket file read-only, but clients reach the Docker API by connecting to the socket, which a read-only mount does not stop.

Networking

Listens on 8080; point the domain at it.

Storage

Volume	Mount	Holds
code-server-home	/home/coder	Home directory: settings, extensions, shell history, CLI logins
code-server-workspace	/workspace	Code you work on

The image's entrypoint opens ., its working directory. entrypoint.sh changes into DEFAULT_WORKSPACE, set to /workspace in compose.yml, before starting it, so that is the folder code-server opens and where new terminals start. Changing the variable moves both without editing the compose file's structure. docker exec shells are not affected and start in the image's /home/coder.

The Dockerfile also makes /workspace writable. The image does not ship that directory, so a named volume mounted there comes up root:root, and coder (uid 1000) cannot write to it. Creating the directory in the image, owned by 1000:1000, fixes that without a runtime step, because Docker seeds an empty named volume from the image's directory, ownership included. The home volume needs no such step, because the image already ships /home/coder owned by coder.

build-essential, bubblewrap, zip and unzip are in the Dockerfile rather than home because their projects publish no standalone binaries; Debian's packages are the install method, and they land outside home. build-essential supplies the gcc and make that native builds expect: node-gyp addons, Python sdists, Rust crates using cc, and Ruby built by rbenv. libffi-dev, libssl-dev, libyaml-dev and zlib1g-dev are the headers a rbenv-built Ruby needs for its fiddle, openssl, psych and zlib extensions; without them rbenv install fails or leaves those out.

The Docker CLI, its Compose and Buildx plugins, and the GitHub CLI come from Docker's and GitHub's signed apt repositories, which is each vendor's documented install for Debian. Neither documents an install into home, and Coolify builds with --pull, so they update with each rebuild rather than by hand. The GitLab CLI is not in the image: GitLab publishes no apt repository, only Homebrew and a community one.

Copies of docker, gh or the plugins left in ~/.local/bin or ~/.docker/cli-plugins from an older setup take precedence over the image's and should be deleted.

Shell

SHELL=/bin/zsh in compose.yml picks the shell. The editor's terminal takes its default from $SHELL first and only falls back to the login shell in /etc/passwd, so the variable is enough, and switching to another shell the image ships means changing one line rather than rebuilding. sudo -E in entrypoint.sh keeps the variable; without it sudo would replace it with root's /bin/bash. The value is written literally, not read from .env, because every deploying shell exports its own SHELL, which interpolation would pick up first.

Image

codercom/code-server:latest is the Debian 13 build and moves with every release. Upstream publishes no major tag.