feature flags don't propagate to windows agents

[Tim Penhey]

Juju feature flags are passed to the agents using an environment variable.

Getting environment variables into the service running the agents on windows does not support this currently. It needs to.

[Gabriel Samfira (gabriel-samfira)]

Passing custom environment variables to a service is not supported on windows. This can be done either via registry keys, or using something like:

https://msdn.microsoft.com/en-us/library/windows/desktop/ms685138%28v=vs.85%29.aspx

So to achieve the goal of actually passing in feature flags, we need to abstract this into something that does the right thing for each supported platform.

Could anyone point me to where feature flags are interpreted by jujud?

[Tim Penhey (thumper)]

Sure,

cmd/jujud/main.go line 31

This sets the feature flags for the JUJUD executable based on the environment variable.

The env var is passed to jujud though either the upstart or systemd script which is created through the cloud init code.

What we'd need to do is have the code that generates the cloud-init config for the windows machines to set the appropriate registry keys that jujud can then access.

We could then have a common method within juju to set the feature flags, so it does the right thing based on the host OS.

[Gabriel Samfira (gabriel-samfira)]

SGTM. Will get on this ASAP.

[Anastasia (anastasia-macmood)]

targeted against old milestone