New to Juju, have some questions

Nolan Darilek nolan at
Tue Nov 8 00:10:26 UTC 2011

Hi folks. I'm new to Juju and am wanting a bit of feedback as to whether 
it will meet our needs. I'm currently struggling with the documentation, 
so if these questions are answered there and I missed them then please 
point me there. :)

My situation is that I'm working with a non-profit group that was 
fortunate enough to inherit more than an entire rack of servers. We have 
some ideas for what to do with this, but I'm thinking of slowly bringing 
capacity online as we need it, then eventually offering that capacity to 
others as needed. So if I need a Tomcat server then that gets 
provisioned. If some working group needs a WordPress installation, then 
that gets provisioned.

It would be great if we could view the servers as a resource which we 
can tap into, rather than "here's the database server for a bunch of 
projects, here's our web server, etc." It looks like Juju enables this. 
At least, the examples show spinning up a WordPress instance, MySQL, 
then linking them together.

The FAQ seems to intonate that only one service per machine is 
supported. Is that still true? That would seem like overkill in the case 
of something like WordPress.

Does Juju support virtualization? Or does it require that services be 
installed to the root filesystems of each machine? IOW, if I spin up a 
MySQL server on the local cloud, then is one machine's root partition 
reconfigured to do this? Or can we just spin up a VM hosting WordPress, 
MySQL and everything else needed, then host that on one of the servers?

And how does Juju map services to machines? IOW, if I start a WordPress 
service somewhere, then is it always available on that same machine? I'm 
just curious as to how you'd go from something like the expose command, 
which seems simple enough, to the case where you have a bunch of 
services hosted on a bunch of different domains. So maybe I have one web 
server doing the routing, but it needs to proxy requests for one domain 
to a Tomcat instance on one box, requests for another to a WordPress 
instance, etc. I just don't know if "expose" handles that, or if I am 
then required to keep a bunch of local IP mappings updated.

Thanks a bunch.

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