arguments no longer passed to plugins if you don't have an environment set

[John A Meinel]

I'm not sure what the specific bug is, but if I'm running a development version of Juju, I end up with:
$ juju charm create
usage: /usr/bin/juju-charm subcommand

  Available subcommands are:
    admin
    create
    get
    getall
    list
    promulgate
    proof
    review
    review-queue
    search
    subscribers
    unpromulgate
    update
ERROR subprocess encountered error code 1

Note that I ran "juju charm create" and it tells me that it is one of the subcommands, but it doesn't actually work.

Now if I run:
/usr/bin/juju charm create
I get a nice help text:
usage: charm-create [-h] charmname [charmhome]
charm-create: error: too few arguments

Also, even if I use the right syntax, charm create doesn't actually work with Dev juju:
$ juju charm create foobar
usage: /usr/bin/juju-charm subcommand

  Available subcommands are:
    admin
    create
...

It turns out that this is because of environCommandWrapper which *requires* that an environment is set for the command. I don't have a default Environment. If I run it with an environment it works:
$ juju args -e local a b
['/home/jameinel/dev/go/bin/juju-args', '-e', 'local', 'a', 'b']

[John A Meinel (jameinel)]

So if I hack "juju-charm" to print out sys.argv I get:
$ /usr/bin/juju charm create -h
args ['/usr/bin/juju-charm', 'create', '-h']
vs
$ juju charm create -h
args ['/usr/bin/juju-charm']

So I think this is just a critical regression in core where we used to pass along arguments to plugins, and we stopped doing so.

[John A Meinel (jameinel)]

I just tested juju 1.20 (built from source), and it fails in the same way.

[John A Meinel (jameinel)]

To test this, I have the following plugin in my path:
$ cat ~/dev/go/bin/juju-args
#!/usr/bin/python

import sys
print sys.argv

$ /usr/bin/juju args a b; /usr/bin/juju --version
['/home/jameinel/dev/go/bin/juju-args', 'a', 'b']
1.18.1-trusty-amd64

$ juju args a b; juju --version
['/home/jameinel/dev/go/bin/juju-args']
1.20.6-trusty-amd64

[John A Meinel (jameinel)]

So it looks like this is caused by having this code:
line 51 plugin.go:
 plugin := envcmd.Wrap(&PluginCommand{name: cmdName})

Specifically, we are wrapping PluginCommand into an environCommandWrapper, and environCommandWrapper has its own Init function. and in *that* code we have:

func (w *environCommandWrapper) Init(args []string) error {
 if err := w.ensureEnvName(); err != nil {
  return err
 }
 w.SetEnvName(w.envName)
 return w.EnvironCommand.Init(args)
}

And that *only* succeeds if you have an environment set.
I personally do *not* have a default environment, I always specify it when I want to do something (juju bootstrap -e foo, juju deploy -e foo ubuntu, etc).

As such, there is no environment, but these plugins don't *need* an environment, it actually does nothing with them.
Note that not all plugins are ok without an environment (for example juju backup needs an environment), but the plugin should get to decide.

[John A Meinel (jameinel)]

The other issue is that on line 67 of plugin.go we do:
 plugin.Init(args)
Which means we are ignoring the fact that environCommandWrapper is returning an error and assuming everything is ok.

Which it *is* ok except we didn't end up initializing the plugin arguments like we thought we were doing.

[John A Meinel (jameinel)]

FWIW, this *is* a regression.
juju charm create works with 1.18 but *fails* with 1.20.

On Thu, Aug 21, 2014 at 5:05 AM, Tim Penhey <email address hidden>
wrote:

> ** Changed in: juju-core
> Assignee: John A Meinel (jameinel) => Tim Penhey (thumper)
>
> ** Changed in: juju-core
> Importance: Critical => High
>
> ** Changed in: juju-core/1.20
> Importance: Critical => High
>
> ** Tags removed: regression
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1359170
>
> Title:
> arguments no longer passed to plugins if you don't have an environment
> set
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/charm-tools/+bug/1359170/+subscriptions
>

[John A Meinel (jameinel)]

I suppose you could contend that my method of working doesn't occur in the
wild? And so while it is a clear regression for *me* nobody else would run
into it?

John
=:->

On Thu, Aug 21, 2014 at 11:59 AM, John Meinel <email address hidden>
wrote:

> FWIW, this *is* a regression.
> juju charm create works with 1.18 but *fails* with 1.20.
>
>
>
> On Thu, Aug 21, 2014 at 5:05 AM, Tim Penhey <email address hidden>
> wrote:
>
>> ** Changed in: juju-core
>> Assignee: John A Meinel (jameinel) => Tim Penhey (thumper)
>>
>> ** Changed in: juju-core
>> Importance: Critical => High
>>
>> ** Changed in: juju-core/1.20
>> Importance: Critical => High
>>
>> ** Tags removed: regression
>>
>> --
>> You received this bug notification because you are subscribed to the bug
>> report.
>> https://bugs.launchpad.net/bugs/1359170
>>
>> Title:
>> arguments no longer passed to plugins if you don't have an environment
>> set
>>
>> To manage notifications about this bug go to:
>> https://bugs.launchpad.net/charm-tools/+bug/1359170/+subscriptions
>>
>
>

[Tim Penhey (thumper)]

On 21/08/14 20:01, John A Meinel wrote:
> I suppose you could contend that my method of working doesn't occur in the
> wild? And so while it is a clear regression for *me* nobody else would run
> into it?
>
> John
> =:->

Sorry, I hadn't realised that it used to work with 1.18. The envcmd
work must have happened during 1.20 then.

My fix has landed on master, but not on the 1.20 branch.

Tim