flannel: doc fix and check for missing subnet.env fields

- Document that flannel outputs FLANNEL_NETWORK b/c we use it
- Check and error out if expecited fields are missing in subnetEnv file

Fixes #72

diff --git a/Documentation/flannel.md b/Documentation/flannel.md
index e223ddb..2399ac4 100644 (file)
--- a/Documentation/flannel.md
+++ b/Documentation/flannel.md
@@ -4,7 +4,8 @@
 This plugin is designed to work in conjunction with [flannel](https://github.com/coreos/flannel), a network fabric for containers.
 When flannel daemon is started, it outputs a `/run/flannel/subnet.env` file that looks like this:
 ```
-FLANNEL_SUBNET=10.1.17.0/24
+FLANNEL_NETWORK=10.1.0.0/16
+FLANNEL_SUBNET=10.1.17.1/24
 FLANNEL_MTU=1472
 FLANNEL_IPMASQ=true
 ```

diff --git a/plugins/meta/flannel/flannel.go b/plugins/meta/flannel/flannel.go
index 60de6af..af62973 100644 (file)
--- a/plugins/meta/flannel/flannel.go
+++ b/plugins/meta/flannel/flannel.go
@@ -48,8 +48,26 @@ type NetConf struct {
 type subnetEnv struct {
        nw     *net.IPNet
        sn     *net.IPNet
-       mtu    uint
-       ipmasq bool
+       mtu    *uint
+       ipmasq *bool
+}
+
+func (se *subnetEnv) missing() string {
+       m := []string{}
+
+       if se.nw == nil {
+               m = append(m, "FLANNEL_NETWORK")
+       }
+       if se.sn == nil {
+               m = append(m, "FLANNEL_SUBNET")
+       }
+       if se.mtu == nil {
+               m = append(m, "FLANNEL_MTU")
+       }
+       if se.ipmasq == nil {
+               m = append(m, "FLANNEL_IPMASQ")
+       }
+       return strings.Join(m, ", ")
 }
 
 func loadFlannelNetConf(bytes []byte) (*NetConf, error) {
@@ -92,16 +110,22 @@ func loadFlannelSubnetEnv(fn string) (*subnetEnv, error) {
                        if err != nil {
                                return nil, err
                        }
-                       se.mtu = uint(mtu)
+                       se.mtu = new(uint)
+                       *se.mtu = uint(mtu)
 
                case "FLANNEL_IPMASQ":
-                       se.ipmasq = parts[1] == "true"
+                       ipmasq := parts[1] == "true"
+                       se.ipmasq = &ipmasq
                }
        }
        if err := s.Err(); err != nil {
                return nil, err
        }
 
+       if m := se.missing(); m != "" {
+               return nil, fmt.Errorf("%v is missing %v", fn, m)
+       }
+
        return se, nil
 }
 
@@ -182,7 +206,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 
        if !hasKey(n.Delegate, "ipMasq") {
                // if flannel is not doing ipmasq, we should
-               ipmasq := !fenv.ipmasq
+               ipmasq := !*fenv.ipmasq
                n.Delegate["ipMasq"] = ipmasq
        }