Set default for the safe_interval option of verdi computer configure

[sphuber]

Fixes #2880

The safe_interval is a common option for all Transport types but its
default value is class dependent. Since it is a common option it was
defined in the Transport base class, but since it is defined as a
class attribute, the default cannot be set yet. Keeping this design, the
only option to insert the class specific default is in auth_options
the class property that returns the options for the CLI. By adding the
default here, verdi computer configure local localhost -n will now
work without prompting for its only option safe_interval as it will
simply use the default.

[ltalirz]

thanks a lot for the fix @sphuber
man, this is nasty code to fix...

Given that the ..._options_... lists already contain click-specific code, it seems to me that rather than trying to synthesize the click commands from some custom format, the much more straightforward solution would be to define the click commands explicitly, and to extract from them whatever is needed through inspection:

import click

@click.command()
@click.option('--count', default=1, help='Number of greetings.')
@click.option('--name', prompt='Your name',
              help='The person to greet.')
def hello(count, name):
    """Simple program that greets NAME for a total of COUNT times."""
    for x in range(count):
        click.echo('Hello %s!' % name)

print(hello.params)

Perhaps we should open an issue for this...

[ltalirz]

hm, nasty...
how about making _common_auth_options and _valid_auth_options OrderedDicts themselves. that would make accessing them easier

[sphuber]

That will make it impossible to set the correct default though, see the comment.

[ltalirz]

hm... I don't quite follow. How does _common_auth_options being an OrderedDict instead of a list of tuples change this?
Anyhow it would just be a minor improvement, not important.

[sphuber]

man, this is nasty code to fix...

Given that the ..._options_... lists already contain click-specific code, it seems to me that rather than trying to synthesize the click commands from some custom format, the much more

That will remove the functionality that the verdi computer configure commands are created automatically for all registered transports. Once you remove this, people will have to define these commands manually and explicitly.

[ltalirz]

That will remove the functionality that the verdi computer configure commands are created automatically for all registered transports. Once you remove this, people will have to define these commands manually and explicitly.

Right - it would mean you need to write the click command and the transport class (that inspects it) together, which might be less effort than writing just the transport class with the current machinery.

Anyhow, it would also not be ideal.
For me this PR is good to merge!