state: Add networks doc for services

state/networks.go

+// Copyright 2014 Canonical Ltd.
+// Licensed under the AGPLv3, see LICENCE file for details.
+
+package state
+
+import (
+        "labix.org/v2/mgo"
+        "labix.org/v2/mgo/txn"
+
+        "launchpad.net/juju-core/errors"
+)
+
+// serviceNetworksDoc represents the network restrictions for a service

[dimitern, 2014/03/21 14:21:56]

Since we'll be using this for services, machines and possibly units, let's call
it networksDoc and make it non-service-specific.

Also, I'd prefer IncludedNetworks []string and ExcludedNetworks []string. No
need for *[]string.

Finally, I'd mention that the document ID field is the globalKey of a service or
machine.

[gz, 2014/03/21 15:46:00]

What exactly does "make it non-service-specific" entail? I didn't understand
that from the log between you and William.
Copied from what tags in contraints uses... Can omit the pointer if mongo
doesn't care.
In the comment here? Ok.

[gz, 2014/03/21 16:31:05]

Done.

+type serviceNetworksDoc struct {
+        NetworksToInclude *[]string
+        NetworksToExclude *[]string
+}
+
+func newServiceNetworksDoc(includeNetworks, excludeNetworks []string) serviceNetworksDoc {
+        return serviceNetworksDoc{
+                NetworksToInclude: &includeNetworks,
+                NetworksToExclude: &excludeNetworks,
+        }
+}
+
+func createServiceNetworksOp(st *State, id string, includeNetworks, excludeNetworks []string) txn.Op {
+        return txn.Op{
+                C:      st.serviceNetworks.Name,
+                Id:     id,
+                Assert: txn.DocMissing,
+                Insert: newServiceNetworksDoc(includeNetworks, excludeNetworks),
+        }
+}
+
+// While networks are immutable, there is no setServiceNetworksOp function

[dimitern, 2014/03/21 14:21:56]

No need to mention this for now - I'd just drop it.

[gz, 2014/03/21 16:31:05]

Keeping, just because I'll forget why otherwise, even if it's obvious to
everyone else. :)

+
+func removeServiceNetworksOp(st *State, id string) txn.Op {
+        return txn.Op{
+                C:      st.serviceNetworks.Name,
+                Id:     id,
+                Remove: true,
+        }
+}
+
+func readServiceNetworks(st *State, id string) (includeNetworks, excludeNetworks []string, err error) {
+        doc := serviceNetworksDoc{}
+        if err = st.serviceNetworks.FindId(id).One(&doc); err == mgo.ErrNotFound {
+                err = errors.NotFoundf("service networks")
+        } else if err == nil {
+                includeNetworks = *doc.NetworksToInclude
+                excludeNetworks = *doc.NetworksToExclude
+        }
+        return includeNetworks, excludeNetworks, err
+}