mesheryctl: Make `mesheryctl init` an internal function only; Do not expose `init` as a command line operation

[leecalcote]

Current Behavior
Users can directly invoke mesheryctl init. This command is intended for use by other mesheryctl commands, not for use by users.

See Meshery Installation & Packaging for more information.

Desired Behavior
Hide init from user invocation.

[jesuslerma]

Hi, Lee.

When we're going to call the init command by start and update?

[jesuslerma]

We can name that function to something like: installPrereq and move it to vars.go.

[leecalcote]

We can name that function to something like: installPrereq and move it to vars.go.

@jesuslerma spot on. Yes, your suggestion is ideal.

[leecalcote]

When we're going to call the init command by start and update?

Given init's current functionality, the most appropriate time to call it is upon finding that certain prerequisites are missing (namely docker-compose at the moment). Ultimately, init (or function(s) that replace it, should include more preflight / prerequisite checks like ensuring that the user's $HOME is writeable or that the current user has permission to execute docker-compose up and so on).

[leecalcote]

@jesuslerma @anandrkskd how did we make out on this issue?