Reduce api-cli default verbosity

[DavidePrincipi]

The api-cli command is frequently used during system maintenance or customization procedures.

In addition to the expected JSON output, many NS8 actions write supplementary information to standard error, which api-cli relays to its own stderr. These messages are often not actual errors but debug lines, which can be confusing or misleading.

Proposed solution

1. Reduce the default verbosity of the command by omitting stderr relaying when the action completes successfully. If the action exits with a non-zero status, print the stderr output as currently done.
2. Remove the "default cluster credentials" warning message. Improve error reporting when the action fails due to missing authorizations.

See also

• Discussion: https://mattermost.nethesis.it/nethesis/pl/xy4ng9acxbgbjyexh545s3u4he

[DavidePrincipi]

In Testing, core 3.14.0-dev.1

The following commands were changed:

• api-cli
• add-module
• add-user
• grant-actions
• remove-module
• remove-user
• revoke-actions

Test case 0

If invoked by root in the leader node, a command like this no longer prints the message Warning: using user "cluster" credentials from the environment

api-cli run list-users

Test case 1

If api-cli runs an unauthorized action a specific error message is printed. E.g.

 runagent -m traefik1 api-cli run list-modules

Test case 2

Changed commands:

• do not print stderr on success
• print stderr with non-zero exit codes
• print stdout (JSON) if it contains important information, e.g. avoid printing useless strings like "True" "None" etc...