Improve st2client error messages when parameter missing type

SUMMARY

st2 run error message when action parameter has undefined type is unhelpful. Should be improved.

ISSUE TYPE

• Minor enhancement

STACKSTORM VERSION

2.10.4.

OS / ENVIRONMENT / INSTALL METHOD

Ansible.

STEPS TO REPRODUCE

Create an action that has a parameter with a default value, but no type defined, e.g. username in this action:

---
  name: "wait_for_ssh"
  runner_type: "python-script"
  description: "Action which waits for a SSH server to become accessible. By default, if no credentials are provided, this action will try to authenticate using the system user username and key file."
  enabled: true
  entry_point: "wait_for_ssh.py"
  parameters:
    hostname:
      description: "Remote hostname."
      type: "string"
      required: true
    port:
      description: "Remote SSH port."
      type: "integer"
      required: true
      default: 22
    username:
      description: "Username used to authenticate."
      required: true
      default: "stanley"

If the action is run via CLI without specifying username, it works. If you specify a username, it throws an unhelpful error.

ACTUAL RESULTS

lhill@st2:~$ st2 run linux.wait_for_ssh hostname="127.0.0.1" port="22" username=stanley
ERROR: 'type'

I think there's three options here:

1/ Update st2client to assume that the type is string if not otherwise specified. That is what the rest of our codebase does.
2/ Update the code around here to catch this Exception & log a nicer error message
3/ Change action validation rules to enforce specification of type: parameter, rather than defaulting to string.

I think (1) is the best option, to be consistent with all other usage, and not require user updates to their existing actions. (2) is helpful. (3) should be avoided due to change in behavior requiring widespread re-work.

Start in st2client/st2client/commands/action.py around the referenced line and reproduce the problem with the supplied st2 run command and action definition. Determine how a missing parameter type is handled there; done means the CLI no longer reports only 'type' and follows the issue's intended behavior for omitted types.