JSON output invalid due to errors on stdout

[jorhett]

Describe the bug

JSON output is invalid due to errors on stdout.

To Reproduce

Steps to reproduce the behavior:

1. Without being authenticated, run boundary auth-methods list -format=json 2> /dev/null
2. First line of output is not valid JSON

No saved credential found, continuing without
[{"id":"ampw_foobar","scope_id":"global","scope":{"id": ...

Expected behavior

Valid JSON that could be used by a program, like jq to get the auth method id:

    boundary auth-methods list -format=json |  jq -r '.[] | select(.type=="password").id'

Additional context
Add any other context about the problem here.

This is the required workaround, which is messy:

    boundary auth-methods list -format=json |grep -v 'No saved credential' | jq '.[]'

[jefferai]

This is kind of a tricky one.

We assume that you will want to load a saved token since this would be normal behavior, and that if you don't want to, that you would disable it via -keyring-type none. So arguably this is an error and we should switch it to stderr.

On the other hand, if you aren't expecting a saved token to be available, but have not actually disabled it, then this is useful information but not actually an error, and it's easy to work around by simply telling the CLI not to try to look for a saved token.

So this is really about user expectation. That said, I'm in favor of switching this to stderr, because it will help with output redirection cases and it can still be disabled via setting the keyring type.

[jorhett]

and it's easy to work around by simply telling the CLI not to try to look for a saved token

Just FYI we're putting this in people's shell profiles to simplify logging in... which is before they know what boundary is, nevermind have made a choice about keyring ;-)

export BOUNDARY_AUTH_METHOD_ID=$(\
  boundary auth-methods list -scope-id=global -format=json \
  |  jq -r '.[] | select(.type=="password").id' )