Issue #3910 has been updated by Nigel Kersten.

"What worries me most about this current line of discussion is that it is based 
on entirely practical concerns of load avoidance rather than approaching the 
core issue of configuration management."

I think it's actually the other way around Oliver.

The current code as I understand it will deal with an environment mismatch 
between agent and server by throwing away the catalog that was compiled using 
the agent environment, and instead re-doing the whole process of pluginsync + 
catalog retrieval with the server specified environment.

I am concerned about load here however, particularly in situations where the 
agent doesn't specify an environment (and thus defaults to 'production') and 
the server sets a different environment.

It feels like a better approach would be to do something like:

  * agent requests catalog with environment "A".
  * agent pluginsyncs with environment "A"
  * server notes the mismatch as it is assigning environment "B"
  * agent re-does pluginsync with environment "B"
  * server delivers catalog with environment "B"

so we still maintain the server being able to operate as an authoritative 
source of truth, but remove the second catalog compilation.

It's entirely possible I'm missing something here, so I'll chat to Patrick 
today.
----------------------------------------
Bug #3910: Server is not authoritative over client environment when specified 
in an ENC
https://projects.puppetlabs.com/issues/3910#change-56550

Author: Nigel Kersten
Status: In Topic Branch Pending Review
Priority: Urgent
Assignee: Patrick Carlisle
Category: plumbing
Target version: Telly
Affected Puppet version: 0.25.4
Keywords: 
Branch: https://github.com/puppetlabs/puppet/pull/569


See: 
http://groups.google.com/group/puppet-dev/browse_thread/thread/b609965e377392ec

To summarize, when the client specifies one environment and the classifier 
specifies another, classes are evaluated from the server-specified environment, 
and yet files are retrieved from the client-specified environment.


3 environments defined, each with a single class "base". 
*/etc/puppet/puppet.conf* 
<pre>
<...snip...> 
[one] 
  modulepath = /etc/puppet/environments/one/modules 
[two] 
  modulepath = /etc/puppet/environments/two/modules 
[three] 
  modulepath = /etc/puppet/environments/three/modules 
</pre>

*/etc/puppet/environments/one/modules/base/manifests/init.pp* 
<pre>
class base { 
  notify { "hardwired one": } 
  notify { "variable $environment": } 
  file { "/tmp/environment_test": 
    source => "puppet:///base/tester", 
  } 
} 
</pre>

*/etc/puppet/environments/two/modules/base/manifests/init.pp* 
<pre>
class base { 
  notify { "hardwired two": } 
  notify { "variable $environment": } 
  file { "/tmp/environment_test": 
    source => "puppet:///base/tester", 
  } 
} 
</pre>

*/etc/puppet/environments/three/modules/base/manifests/init.pp* 
<pre>
class base { 
  notify { "hardwired three": } 
  notify { "variable $environment": } 
  file { "/tmp/environment_test": 
    source => "puppet:///base/tester", 
  } 
} 
</pre>

<pre>
$ cat /etc/puppet/environments/{one,two,three}/modules/base/files/tester 
one 
two 
three 
</pre>

Right? So we have two notify resources and a file resource. 
   - The "hardwired" notify is to illustrate which class is being loaded. 
   - The "variable" notify is to illustrate what $environment evaluates to 
   in the manifests. 
   - The file source is to illustrate which file is being sourced. 
I also have an external node classifier that always returns this: 
<pre>
--- 
classes: 
 - base 
environment: one 
</pre>

So our classifier always includes base, and always sets the environment. 
I then invoke a puppet run on a client, specifying the environment to be 
*different* to the classifier. 
Between all of these runs I delete cached client yaml info on the server. 
(find /var/puppet/yaml -type f -delete) 
<pre>
# puppetd -t --environment two 
notice: hardwired one 
notice: //base/Notify[hardwired one]/message: defined 'message' as 
'hardwired one' 
notice: variable two 
notice: //base/Notify[variable two]/message: defined 'message' as 'variable 
two' 
notice: Finished catalog run in 0.18 seconds 
# cat /tmp/environment_test 
two 
</pre>

*So we have the class being evaluated in environment "one", but the file 
being sourced coming from environment "two" ! *And less importantly, 
$environment evaluates to "two". 
* 
* 
Now, to throw the big spanner in the works.... we try not specifying an 
environment at all. 
<pre>
# puppetd -t 
notice: hardwired one 
notice: //base/Notify[hardwired one]/message: defined 'message' as 
'hardwired one' 
notice: variable production 
notice: //base/Notify[variable production]/message: defined 'message' as 
'variable production' 
err: //base/File[/tmp/environment_test]: Failed to retrieve current state of 
resource: Error 400 on SERVER: Not authorized to call find on 
/file_metadata/base/tester Could not retrieve file metadata for 
puppet:///base/tester: Error 400 on SERVER: Not authorized to call find on 
/file_metadata/base/tester at 
/etc/puppet/environments/one/modules/base/manifests/init.pp:6 
notice: Finished catalog run in 0.08 seconds 
</pre>


As we don't have an environment "production" defined at all, the server 
tries to read the metadata from a non-existent environment and fails. 


-- 
You have received this notification because you have either subscribed to it, 
or are involved in it.
To change your notification preferences, please click here: 
http://projects.puppetlabs.com/my/account

-- 
You received this message because you are subscribed to the Google Groups 
"Puppet Bugs" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/puppet-bugs?hl=en.

Reply via email to