Exec

The built-in plugin called exec allows you to execute shell commands from within your HCL configuration.

Have a question?

Check the FAQ to see if there's already an answer.

Configuration

None

Actions

Name	Description
exec_command	Execute a shell command

exec_command

The exec_command action allows you to execute a shell command.

Arguments

Argument	Description	Type	Required
command	The command to execute	string	Yes
dot_env_filename	Name of file for outputs	string	No

Outputs

Output	Description	Type
exit_code	The exit code of the command	number
dot_env	Outputs parsed from dot_env_filename above	map

Usage

plugin exec {}

stage "dev" {
  task "hello_world" {
    action "exec_command" {
      alias = "hello_exec"
      dot_env_filename = ".env"
      command = <<EOF
        echo "Hello, world!"
        echo "example_key=example_value" >> .env
      EOF
    }
  }
}

stage "stage-2" {
  task "get_outputs" {
    action "exec_command" {
      command = <<EOF
        echo "output value : ${action_outputs.stage.dev.task.hello_world.action.hello_exec.dot_env.example_key}"
      EOF
    }
  }
}

In this example, the exec plugin is used to execute the echo "Hello, world!" command. The output of this command will be

• the exit code of the command, which will be 0 if the command was successful.
• a map of any key-value pairs (strings) written to file .env in the first stage.

Frequently Asked Questions (FAQ)

How would I reference the output of this exec action in another?

The full path to the exec action can be used to get its output. For example, if you wanted to reference the exit_code output from the exec action in the example above, you would use action_outputs.stage.dev.task.hello_world.action.exec_command.exit_code in another action.

How can I use a complex variable or output inside of an exec command?

Since the command argument only accepts a string type, you will need to convert the complex variable or output to a string before it can be used. The variable can be passed to the built-in jsonencode function to convert it to a string. For example, if you wanted to use the variable var.my_variable in an exec command, you would use jsonencode(var.my_variable) in the command argument.