openstack team mailing list archive

[Doug Hellmann <doug.hellmann@xxxxxxxxxxxxx>]

On Wed, May 2, 2012 at 1:23 PM, Adam Spiers <aspiers@xxxxxxxx> wrote:

> Dean Troyer (dtroyer@xxxxxxxxx) wrote:
> > On Tue, May 1, 2012 at 2:11 PM, Adam Spiers <aspiers@xxxxxxxx> wrote:
> > > As of my recent patch, --help is contextual in nova:
> >
> > I hadn't seen that yet...
> >
> > > and I have started work on some of the other commands too, so it would
> > > be helpful if we could reach a consensus on this soon ... although
> > > please let me know if I am wasting my time working on other commands
> > > due to any imminent rewrites using python-openstack!
> >
> > The continued existence of the project-specific commands is really up
> > to the projects themselves.  I think it would be great to converge
> > them on things like this, but trying to get them all to work the same
> > is what led us to openstackclient due to backward compatibility and
> > all.  My guess would be that the existing client binaries would live
> > through the 'G' release even if we decided to deprecate them now.
>
> OK, thanks for the info.  So what's the goal for this project - to
> enter the incubation program? to become part of openstack-common?
> Should it be added to http://wiki.openstack.org/Projects ?
>
> > > I agree with Dolph - there is a precedent from other well-known
> > > programs (git, hg, svn are the first ones I can think of) for --help
> > > to behave differently depending on whether or not it was preceded by a
> > > subcommand.  So my vote is that we should definitely aim to adhere to
> > > this pattern.
> >
> > How about detailing it in the HIG and once we get a command or two
> > implemented with argument parsing we give it a shot?
>
> I took a stab at this, but it's beginning to confirm the doubts which
> I wrote about in https://lists.launchpad.net/openstack/msg10956.html
> regarding the decision to have the verb preceding the noun:
>
>    openstack create --help
>    openstack help create
>
> would require grouping of help for all the creation actions together
> which doesn't make much sense to me.  These both seem to make more
> sense:
>
>    openstack endpoint --help
>    openstack help endpoint
>
but would lead to overly long output unless they invoked man(1) on a
> corresponding manual page all about endpoint management, similar to
> how say, 'git remote --help' invokes the git-remote(1) man page which
> covers management of git remotes.
>
> The other option is to support a more fine-grained approach to help:
>
>    openstack create endpoint --help
>    openstack help create endpoint
>
> and then make the help action require both, e.g.
>
>    $ openstack help create
>    Usage: openstack help create OBJECT-TYPE
>
>    Which type of object do you want help creating?
>
>    Available identity types:
>        catalog         ec2-credentials endpoint         role
>        service         tenant          user             user-password
>        user-role
>
>    Available compute types:
>        absolute-limits actions         aggregate        bash-completion
>        cloudpipe       console-log     credentials      diagnostics
>        dns             dns-domain      endpoints        fixed-ip
>        flavor          floating-ip     floating-ip-pool host
>        image           keypair         meta(data)       quota
>        quota-class     rate-limits     resource         root-password
>        secgroup        secgroup-group  secgroup-rule    usage
>        vnc-console     volume          volume-snapshot  volume-type
>        x509-cert       x509-root-cert
>
>    [...]
>
> and ditto for 'openstack create --help'.  (Of course, this is just a
> mockup and incorrectly lists some types which you would never create.)
>
> Here are the classes of use cases I can think of:
>
>  1. User has never/rarely used the (openstack) command before and
>     needs to know overall structure of possible arguments and/or see
>     a brief summary of common "get me started" arguments.
>
>     Suggested implementation:
>         openstack --help
>
>  2. User has used the (openstack) command before but needs to check
>     global options.
>
>     Suggested implementation:
>         openstack --help
>

FTR, both 1 and 2 are implemented today.


>
>  3. User wants to e.g. create something but isn't sure of the exact
>     name of the type of the object to be created.
>
>     Suggested implementation:
>         openstack help create
>         openstack create --help
>

It should be relatively straightforward to have the help command scan all
available commands using the input as a substring if it doesn't match
anything exactly. I think we probably just want to produce the list of
those commands, though, and not go into any more detail than a one-line
description. Doing much more is going to produce far too much output.


>
>  4. User wants to perform one or more actions on a particular type of
>     object e.g. volume, but isn't sure which actions are available.
>
>     Suggested implementation:
>         ????
>

See comment above.


>
>  5. User knows both the action and object type but needs to check
>     details of options / extra positional arguments.
>
>     Suggested implementation:
>         openstack create endpoint --help
>         openstack help create endpoint
>

FTR, the second option is how it works today.


>
> Thoughts?
>
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