Decouple Scope lifecycle from Weave lifecycle

- Run the Weave integrations regardless of if weave is detected.
- Make everything backoff and not spam the logs.
- Add miekg dns to vendor.
- Have the app periodically register with weaveDNS, and the probe do lookups there.
- Decide what the local networks are at runtime, not once at startup.
- Correctly resolve app ids, fixes #825

test/exec/exec.go

@@ -60,6 +60,14 @@ func (c *mockCmd) Kill() error {
 	return nil
 }
 
+func (c *mockCmd) Output() ([]byte, error) {
+	return ioutil.ReadAll(c.ReadCloser)
+}
+
+func (c *mockCmd) Run() error {
+	return nil
+}
+
 func (b *blockingReader) Read(p []byte) (n int, err error) {
 	<-b.quit
 	return 0, nil

test/weave/mock.go

@@ -0,0 +1,71 @@
+package weave
+
+import (
+	"net"
+
+	"github.com/weaveworks/scope/common/weave"
+)
+
+// Constants used for testing
+const (
+	MockWeavePeerName     = "winnebago"
+	MockWeavePeerNickName = "winny"
+	MockContainerID       = "83183a667c01"
+	MockContainerMAC      = "d6:f2:5a:12:36:a8"
+	MockContainerIP       = "10.0.0.123"
+	MockHostname          = "hostname.weave.local"
+)
+
+// MockClient is a mock version of weave.Client
+type MockClient struct{}
+
+// Status implements weave.Client
+func (MockClient) Status() (weave.Status, error) {
+	return weave.Status{
+		Router: weave.Router{
+			Peers: []struct {
+				Name     string
+				NickName string
+			}{
+				{
+					Name:     MockWeavePeerName,
+					NickName: MockWeavePeerNickName,
+				},
+			},
+		},
+		DNS: weave.DNS{
+			Entries: []struct {
+				Hostname    string
+				ContainerID string
+				Tombstone   int64
+			}{
+				{
+					Hostname:    MockHostname + ".",
+					ContainerID: MockContainerID,
+					Tombstone:   0,
+				},
+			},
+		},
+	}, nil
+}
+
+// AddDNSEntry implements weave.Client
+func (MockClient) AddDNSEntry(fqdn, containerid string, ip net.IP) error {
+	return nil
+}
+
+// PS implements weave.Client
+func (MockClient) PS() (map[string]weave.PSEntry, error) {
+	return map[string]weave.PSEntry{
+		MockContainerID: {
+			ContainerIDPrefix: MockContainerID,
+			MACAddress:        MockContainerMAC,
+			IPs:               []string{MockContainerIP},
+		},
+	}, nil
+}
+
+// Expose implements weave.Client
+func (MockClient) Expose() error {
+	return nil
+}