Environment Variables
Use the
coder_env
resource to inject environment variables into your workspace agents. This is
useful for configuring tools, setting paths, and passing configuration to
development environments.
Basic usage
resource "coder_agent" "dev" {
os = "linux"
arch = "amd64"
}
resource "coder_env" "go_path" {
agent_id = coder_agent.dev.id
name = "GOPATH"
value = "/home/coder/go"
}
Each coder_env resource sets a single environment variable on the specified
agent. You can define multiple coder_env resources targeting the same agent.
Merge strategies
When multiple coder_env resources define the same variable name, use the
merge_strategy attribute to control how values are combined:
| Strategy | Behavior |
|---|---|
replace (default) | Last value wins. Backward compatible. |
append | Appends to the existing value with : separator. |
prepend | Prepends to the existing value with : separator. |
error | Fails the build if the variable is already defined. |
The append and prepend strategies use : as a separator, which matches
the convention for PATH-style variables on Unix systems.
Example: Appending to PATH
Multiple coder_env resources can each add directories to PATH:
resource "coder_env" "path_tools" {
agent_id = coder_agent.dev.id
name = "PATH"
value = "/home/coder/tools/bin"
merge_strategy = "append"
}
resource "coder_env" "path_go" {
agent_id = coder_agent.dev.id
name = "PATH"
value = "/home/coder/go/bin"
merge_strategy = "append"
}
This produces PATH with the value
/home/coder/tools/bin:/home/coder/go/bin.
Example: Preventing duplicates
Use error to catch accidental duplicate definitions:
resource "coder_env" "editor" {
agent_id = coder_agent.dev.id
name = "EDITOR"
value = "vim"
merge_strategy = "error"
}
If another coder_env resource also sets EDITOR, the build fails with
a clear error message.
Ordering
When multiple coder_env resources append or prepend to the same variable,
they are processed in alphabetical order by their
Terraform resource address.
In the PATH example above, coder_env.path_go is processed before
coder_env.path_tools because path_go sorts before path_tools
alphabetically.
Agent env override
The env block inside a coder_agent resource always takes final precedence
over any coder_env resources. If both define the same variable, the
coder_agent value wins regardless of merge_strategy. This override happens
after coder_env resources are merged, so merge_strategy = "error" does not
trigger when the conflict is with the agent's env block — only when two
coder_env resources define the same key:
resource "coder_agent" "dev" {
os = "linux"
arch = "amd64"
env = {
PATH = "/usr/local/bin:/usr/bin:/bin"
}
}
# This value is ignored because coder_agent.dev.env sets PATH directly.
resource "coder_env" "extra_path" {
agent_id = coder_agent.dev.id
name = "PATH"
value = "/home/coder/bin"
merge_strategy = "append"
}
See the
Coder Terraform provider documentation
for the complete coder_env reference.