Merge pull request #545 from weaveworks/544-containers-by-hostname

Add containers by hostname view.

app/router.go

@@ -224,6 +224,15 @@ var topologyRegistry = &registry{
 				{"hide", "System containers hidden", true, render.FilterSystem},
 			}},
 		},
+		"containers-by-hostname": {
+			human:    "by hostname",
+			parent:   "containers",
+			renderer: render.ContainerHostnameRenderer,
+			options: optionParams{"system": {
+				{"show", "System containers shown", false, nop},
+				{"hide", "System containers hidden", true, render.FilterSystem},
+			}},
+		},
 		"hosts": {
 			human:    "Hosts",
 			parent:   "",

probe/docker/container.go

@@ -22,11 +22,12 @@ import (
 
 // These constants are keys used in node metadata
 const (
-	ContainerName    = "docker_container_name"
-	ContainerCommand = "docker_container_command"
-	ContainerPorts   = "docker_container_ports"
-	ContainerCreated = "docker_container_created"
-	ContainerIPs     = "docker_container_ips"
+	ContainerName     = "docker_container_name"
+	ContainerCommand  = "docker_container_command"
+	ContainerPorts    = "docker_container_ports"
+	ContainerCreated  = "docker_container_created"
+	ContainerIPs      = "docker_container_ips"
+	ContainerHostname = "docker_container_hostname"
 
 	NetworkRxDropped = "network_rx_dropped"
 	NetworkRxBytes   = "network_rx_bytes"
@@ -70,6 +71,7 @@ type Container interface {
 	ID() string
 	Image() string
 	PID() int
+	Hostname() string
 	GetNode([]net.IP) report.Node
 
 	StartGatheringStats() error
@@ -100,6 +102,15 @@ func (c *container) PID() int {
 	return c.container.State.Pid
 }
 
+func (c *container) Hostname() string {
+	if c.container.Config.Domainname == "" {
+		return c.container.Config.Hostname
+	}
+
+	return fmt.Sprintf("%s.%s", c.container.Config.Hostname,
+		c.container.Config.Domainname)
+}
+
 func (c *container) StartGatheringStats() error {
 	c.Lock()
 	defer c.Unlock()
@@ -221,6 +232,7 @@ func (c *container) GetNode(localAddrs []net.IP) report.Node {
 		ImageID:          c.container.Image,
 		ContainerIPs: strings.Join(append(c.container.NetworkSettings.SecondaryIPAddresses,
 			c.container.NetworkSettings.IPAddress), " "),
+		ContainerHostname: c.Hostname(),
 	})
 	AddLabels(result, c.container.Config.Labels)
 

probe/docker/container_linux_test.go

@@ -80,7 +80,7 @@ func TestContainer(t *testing.T) {
 	test.Poll(t, 100*time.Millisecond, want, func() interface{} {
 		node := c.GetNode([]net.IP{})
 		for k, v := range node.Metadata {
-			if v == "0" {
+			if v == "0" || v == "" {
 				delete(node.Metadata, k)
 			}
 		}

probe/docker/registry_test.go

@@ -31,6 +31,10 @@ func (c *mockContainer) Image() string {
 	return c.c.Image
 }
 
+func (c *mockContainer) Hostname() string {
+	return ""
+}
+
 func (c *mockContainer) StartGatheringStats() error {
 	return nil
 }

render/mapping.go

@@ -484,7 +484,7 @@ func MapContainer2ContainerImage(n RenderableNode, _ report.Networks) Renderable
 		return RenderableNodes{}
 	}
 
-	// Add container-<id> key to NMD, which will later be counted to produce the minor label
+	// Add container id key to the counters, which will later be counted to produce the minor label
 	result := NewDerivedNode(id, n)
 	result.Node.Counters[containersKey] = 1
 	return RenderableNodes{id: result}
@@ -594,6 +594,29 @@ func MapContainer2Pod(n RenderableNode, _ report.Networks) RenderableNodes {
 	return RenderableNodes{id: result}
 }
 
+// MapContainer2Hostname maps container RenderableNodes to 'hostname' renderabled nodes..
+func MapContainer2Hostname(n RenderableNode, _ report.Networks) RenderableNodes {
+	// Propogate all pseudo nodes
+	if n.Pseudo {
+		return RenderableNodes{n.ID: n}
+	}
+
+	// Otherwise, if some some reason the container doesn't have a hostname
+	// (maybe slightly out of sync reports), just drop it
+	id, ok := n.Node.Metadata[docker.ContainerHostname]
+	if !ok {
+		return RenderableNodes{}
+	}
+
+	result := NewDerivedNode(id, n)
+	result.LabelMajor = id
+	result.Rank = id
+
+	// Add container id key to the counters, which will later be counted to produce the minor label
+	result.Node.Counters[containersKey] = 1
+	return RenderableNodes{id: result}
+}
+
 // MapCountContainers maps 1:1 container image nodes, counting
 // the number of containers grouped together and putting
 // that info in the minor label.

render/topologies.go

@@ -171,6 +171,16 @@ var ContainerImageRenderer = Map{
 	},
 }
 
+// ContainerHostnameRenderer is a Renderer which produces a renderable container
+// by hostname graph..
+var ContainerHostnameRenderer = Map{
+	MapFunc: MapCountContainers,
+	Renderer: Map{
+		MapFunc:  MapContainer2Hostname,
+		Renderer: ContainerRenderer,
+	},
+}
+
 // AddressRenderer is a Renderer which produces a renderable address
 // graph from the address topology.
 var AddressRenderer = Map{