Understanding the space constraint

juju
1

I’m looking through one of the examples in juju help deploy and am slightly confused.

Deploy to a machine that is in the ‘dmz’ network space, but not in either the ‘cms’ nor the ‘database’ spaces:

juju deploy haproxy -n 2 --constraints spaces=dmz,^cms,^database

I see the intent… but… are the “negative” constraints redundant? That is, “^cms” and “^database” should not be required here. If it I have specified the “dmz” space, is it possible for units of the application to somehow slip into other spaces?

1 Like
2

Yes, a machine can be on multiple networks. Here we’re saying the two resulting machines must be on one network but not on two other networks.

3

Ah of course, that makes sense. Thanks for resolving this for me :slight_smile: