Inconsistencies between juju debug-hooks and "normal" hook environment

[Cory Johns]

Merlijn,

That is an annoying inconsistency.  It's probably related to debug-hooks
bootstrapping itself via `juju ssh` which logs in as the ubuntu user since
root ssh is disabled, as well as it being unlikely that the actual hook
context is a login shell.

I imagine the generate-config error is due to the lack of either $HOME or
$JUJU_HOME being set.  I would recommend trying explicitly setting
JUJU_HOME=/home/ubuntu before calling generate-config and see if that works
around it.

I've also created a bug against juju-core for this:
https://github.com/juju/juju/issues/3449

On Tue, Oct 6, 2015 at 10:06 AM, Merlijn Sebrechts <
merlijn.sebrechts at gmail.com> wrote:

>
> Hi Matt
>
>
> Thank you for your response. It was nice seeing you too!
>
> Let me explain my two, maybe related problems a bit more:
>
>
> 1. Home directory is different between debug and non-debug hook context.
>
>    - Using the manual provider.
>    - When deploying a Charm, the install hook is run as the "root" user.* "echo
>    ~" prints "/root".*
>    - When the install hook crashes, I connect to the unit using
>    `debug-hooks` and restart the install hook as you described using  'juju
>    resolved --retry unit/#'. After a while, tmux shows "[unit/0] 0:bash-
>    1:install* " at the bottom and cwd is '/var/lib/juju/agents/unit-0/charm'.
>    As I understand, I am now in the hook context, right? *However, "echo
>    ~" prints "/home/ubuntu".* Even though the current user is root.
>
>
>
> 2. Something causes "juju init" to fail in non-debug hook context and
> succeeds in debug hook context.
>
>
>    - Using manual provider
>    - Executing `juju init` or `juju generate-config` in a hook results in
>    the error message `error: cannot determine juju home, required
>    environment variables are not set`
>    - Executing `juju init` or `juju generate-config` in the hook context
>    using  `debug-hooks` and  'juju resolved --retry unit/#` succeeds.
>
>
> My current workaround is to generate the initial juju config myself and
> not use "juju generate-config". However, I'm not sure if this behavior is
> intentional or a bug.
>
>
> Thanks in advance!
>
>
> 2015-10-06 15:37 GMT+02:00 Matt Bruzek <matthew.bruzek at canonical.com>:
>
>> Hell again Merlijn,
>>
>> It was nice to see you at the Charmer summit!  This is a very interesting
>> use of Juju.
>>
>> What you are seeing is what we call a "hook context".  Hooks execute with
>> root authority and have certain environment variables are set. This is so
>> Juju commands and tools work correctly.  The debug-hooks command puts you
>> into a "hook context" when you run  'juju resolved --retry unit/#'
>>
>> As I wrote all hooks are executed with these environment variables set.
>> If you are running the install script manually outside of a hook context
>> these environment variables would not be set.
>>
>> There is more information about the environment variables here:
>>
>> https://jujucharms.com/docs/devel/authors-hook-environment
>>
>> However, I don't see "JUJU_HOME" listed on this page. Perhaps you could
>> give me more information on what variable is causing a problem and perhaps
>> your hooks could set those values in the case where the script runs
>> manually.
>>
>> Cheers!
>>
>>    - Matt Bruzek <matthew.bruzek at canonical.com>
>>
>> On Tue, Oct 6, 2015 at 5:07 AM, Merlijn Sebrechts <
>> merlijn.sebrechts at gmail.com> wrote:
>>
>>> Hi
>>>
>>>
>>> I'm developing a Charm that installs the Juju client, among other
>>> things. I'm having some trouble getting this to work. When I use juju
>>> debug-hooks and manually run the install hook, everything works fine.
>>> However, when the hook is executed by Juju automatically, I get strange
>>> errors such as "error: cannot determine juju home, required environment
>>> variables are not set"
>>>
>>> Both the debug-hooks and the normal hook environment execute as root.
>>> However, a lot of env vars are different, like the home dir.
>>>
>>> Debug-hooks:
>>>     echo ~ : /home/ubuntu
>>> hook env:
>>>     echo ~: /root
>>>
>>> Is this intentional? This causes a lot of bugs that cannot be reproduced
>>> by debug-hooks. Is there a way to solve  "error: cannot determine juju
>>> home, required environment variables are not set"?
>>>
>>>
>>>
>>> Kind regards
>>> Merlijn Sebrechts
>>>
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>>> Juju at lists.ubuntu.com
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>>>
>>
>
>
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