Atmos Subcommands

Atmos can be easily extended to support any number of custom commands, what we call "subcommands".

Subcommands are exposed through the atmos CLI when you run atmos help. It's a great way to centralize the way operational tools are run in order to improve DX.

For example, one great way to use subcommands is to tie all the miscellaneous scripts into one consistent CLI interface. Then we can kiss those ugly, inconsistent arguments to bash scripts goodbye! Just wire up the commands in atmos to call the script. Then developers can just run atmos help and discover all available commands.

Simple Example

Here is a example to play around with to get started.

Adding the following to atmos.yaml will introduce a new hello command.

# subcommands
commands:
  - name: hello
    description: This command says Hello world
    steps:
      - "echo Hello world!"

We can run this example like this:

atmos hello

Positional Arguments

Atmos also can support positional arguments. Arguments do not support default values and are required if defined.

If we add the following to atmos.yaml, will introduce a new hello command that accepts one name argument.

# subcommands
commands:
  - name: hello
    description: This command says Hello world
    steps:
      - "echo Hello world {{ .Arguments.name }}!"
    arguments:
      - name: name
        description: Name to greet    

We can run this example like this:

atmos hello world

Passing Flags

Passing flags works much like passing positional arguments, except for that they are passed using long or short flags. Flags can be optional.

# subcommands
commands:
  - name: hello
    description: This command says Hello world
    steps:
      - "echo Hello world {{ .Arguments.name }}!"
    flags:
    - name: name
      shorthand: n
      description: Name to greet
      required: true  

We can run this example like this, using the long flag:

atmos hello --name world

Or, using the shorthand, we can just write:

atmos hello -n world