Examples
Script Example
This example shows a complete, production-ready script that starts Claude Code only after a repository has been cloned. It includes error handling, graceful degradation, and cleanup on exit:
#!/bin/bash
set -euo pipefail
UNIT_NAME="claude-code"
DEPENDENCIES="git-clone"
REPO_DIR="/workspace/repo"
# Track if sync started successfully
SYNC_STARTED=0
# Declare dependencies
if [ -n "$DEPENDENCIES" ]; then
if command -v coder > /dev/null 2>&1; then
IFS=',' read -ra DEPS <<< "$DEPENDENCIES"
for dep in "${DEPS[@]}"; do
dep=$(echo "$dep" | xargs)
if [ -n "$dep" ]; then
echo "Waiting for dependency: $dep"
coder exp sync want "$UNIT_NAME" "$dep" > /dev/null 2>&1 || \
echo "Warning: Failed to register dependency $dep, continuing..."
fi
done
else
echo "Coder CLI not found, running without sync coordination"
fi
fi
# Start sync and track success
if [ -n "$UNIT_NAME" ]; then
if command -v coder > /dev/null 2>&1; then
if coder exp sync start "$UNIT_NAME" > /dev/null 2>&1; then
SYNC_STARTED=1
echo "Started sync: $UNIT_NAME"
else
echo "Sync start failed or not available, continuing without sync..."
fi
fi
fi
# Ensure completion on exit (even if script fails)
cleanup_sync() {
if [ "$SYNC_STARTED" -eq 1 ] && [ -n "$UNIT_NAME" ]; then
echo "Completing sync: $UNIT_NAME"
coder exp sync complete "$UNIT_NAME" > /dev/null 2>&1 || \
echo "Warning: Sync complete failed, but continuing..."
fi
}
trap cleanup_sync EXIT
# Now do the actual work
echo "Repository cloned, starting Claude Code"
cd "$REPO_DIR"
claude
This script demonstrates several best practices:
- Checking for Coder CLI availability before using sync commands
- Tracking whether
coder exp syncstarted successfully - Using
trapto ensure completion even if the script exits early - Graceful degradation when
coder exp syncisn't available - Redirecting
coder exp syncoutput to reduce noise in logs
Template Migration Example
Below is a simple example Docker template that clones Miguel Grinberg's example Flask repo using the git-clone module and installs the required dependencies for the project:
- Python development headers (required for building some Python packages)
- Python dependencies from the project's
requirements.txt
We've omitted some details (such as persistent storage) for brevity, but these are easily added.
Before
data "coder_provisioner" "me" {}
data "coder_workspace" "me" {}
data "coder_workspace_owner" "me" {}
resource "docker_container" "workspace" {
count = data.coder_workspace.me.start_count
image = "codercom/enterprise-base:ubuntu"
name = "coder-${data.coder_workspace_owner.me.name}-${lower(data.coder_workspace.me.name)}"
entrypoint = ["sh", "-c", coder_agent.main.init_script]
env = [
"CODER_AGENT_TOKEN=${coder_agent.main.token}",
]
}
resource "coder_agent" "main" {
arch = data.coder_provisioner.me.arch
os = "linux"
}
module "git-clone" {
count = data.coder_workspace.me.start_count
source = "registry.coder.com/coder/git-clone/coder"
version = "1.2.3"
agent_id = coder_agent.main.id
url = "https://github.com/miguelgrinberg/microblog"
}
resource "coder_script" "setup" {
count = data.coder_workspace.me.start_count
agent_id = coder_agent.main.id
display_name = "Installing Dependencies"
run_on_start = true
script = <<EOT
sudo apt-get update
sudo apt-get install --yes python-dev-is-python3
cd ${module.git-clone[count.index].repo_dir}
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
EOT
}
We can note the following issues in the above template:
- There is a race between cloning the repository and the
pip installcommands, which can lead to failed workspace startups in some cases. - The
aptcommands can run independently of thegit clonecommand, meaning that there is a potential speedup here.
Based on the above, we can improve both the startup time and reliability of the template by splitting the monolithic startup script into multiple independent scripts:
- Install
aptdependencies - Install
pipdependencies (depends on thegit-clonemodule and the above step)
After
Here is the updated version of the template:
data "coder_provisioner" "me" {}
data "coder_workspace" "me" {}
data "coder_workspace_owner" "me" {}
resource "docker_container" "workspace" {
count = data.coder_workspace.me.start_count
image = "codercom/enterprise-base:ubuntu"
name = "coder-${data.coder_workspace_owner.me.name}-${lower(data.coder_workspace.me.name)}"
entrypoint = ["sh", "-c", coder_agent.main.init_script]
env = [
"CODER_AGENT_TOKEN=${coder_agent.main.token}",
"CODER_AGENT_SOCKET_SERVER_ENABLED=true"
]
}
resource "coder_agent" "main" {
arch = data.coder_provisioner.me.arch
os = "linux"
}
module "git-clone" {
count = data.coder_workspace.me.start_count
source = "registry.coder.com/coder/git-clone/coder"
version = "1.2.3"
agent_id = coder_agent.main.id
url = "https://github.com/miguelgrinberg/microblog/"
post_clone_script = <<-EOT
coder exp sync start git-clone && coder exp sync complete git-clone
EOT
}
resource "coder_script" "apt-install" {
count = data.coder_workspace.me.start_count
agent_id = coder_agent.main.id
display_name = "Installing APT Dependencies"
run_on_start = true
script = <<EOT
trap 'coder exp sync complete apt-install' EXIT
coder exp sync start apt-install
sudo apt-get update
sudo apt-get install --yes python-dev-is-python3
EOT
}
resource "coder_script" "pip-install" {
count = data.coder_workspace.me.start_count
agent_id = coder_agent.main.id
display_name = "Installing Python Dependencies"
run_on_start = true
script = <<EOT
trap 'coder exp sync complete pip-install' EXIT
coder exp sync want pip-install git-clone apt-install
coder exp sync start pip-install
cd ${module.git-clone[count.index].repo_dir}
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
EOT
}
A short summary of the changes:
- We've added
CODER_AGENT_SOCKET_SERVER_ENABLED=trueto the environment variables of the Docker container in which the Coder agent runs. - We've broken the monolithic "setup" script into two separate scripts: one for the
aptcommands, and one for thepipcommands.- In each script, we've added a
coder exp sync start $SCRIPT_NAMEcommand to mark the startup script as started. - We've also added an exit trap to ensure that we mark the startup scripts as completed. Without this, the
coder exp sync waitcommand would eventually time out.
- In each script, we've added a
- We have used the
post_clone_scriptfeature of thegit-clonemodule to allow waiting on the Git repository clone. - In the
pip-installscript, we have declared a dependency on bothgit-cloneandapt-install.
With these changes, the startup time has been reduced significantly and there is no longer any possibility of a race condition.


