From bf49e12094ee3720064d6e71ee86be0f1a5fd7d9 Mon Sep 17 00:00:00 2001
From: Peter Bourgon <peter@bourgon.org>
Date: Tue, 26 May 2015 12:59:09 +0200
Subject: [PATCH] Add Containers topology

---
 app/api_topologies_test.go     |  2 +-
 app/router.go                  |  1 +
 app/scope_test.go              |  1 -
 probe/docker_process_mapper.go |  3 ++-
 report/mapping_functions.go    | 31 +++++++++++++++++++++++++++++++
 report/mapping_test.go         | 32 ++++++++++++++++++++++++++++++++
 6 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/app/api_topologies_test.go b/app/api_topologies_test.go
index ea76bb1b98..0c9b67da4e 100644
--- a/app/api_topologies_test.go
+++ b/app/api_topologies_test.go
@@ -15,7 +15,7 @@ func TestAPITopology(t *testing.T) {
 	if err := json.Unmarshal(body, &topos); err != nil {
 		t.Fatalf("JSON parse error: %s", err)
 	}
-	equals(t, 2, len(topos))
+	equals(t, 3, len(topos))
 	for _, topo := range topos {
 		is200(t, ts, topo.URL)
 		if topo.GroupedURL != "" {
diff --git a/app/router.go b/app/router.go
index 02427c1a0d..0b9c51a2a5 100644
--- a/app/router.go
+++ b/app/router.go
@@ -47,5 +47,6 @@ var topologyRegistry = map[string]struct {
 	hasGrouped bool
 }{
 	"applications": {"Applications", selectProcess, report.ProcessPID, true},
+	"containers":   {"Containers", selectProcess, report.ProcessContainer, true},
 	"hosts":        {"Hosts", selectNetwork, report.NetworkHostname, false},
 }
diff --git a/app/scope_test.go b/app/scope_test.go
index a9d9caa943..68d350ae18 100644
--- a/app/scope_test.go
+++ b/app/scope_test.go
@@ -69,7 +69,6 @@ func checkRequest(t *testing.T, ts *httptest.Server, method, path string, body [
 
 // getRawJSON GETs a file, checks it is JSON, and returns the non-parsed body
 func getRawJSON(t *testing.T, ts *httptest.Server, path string) []byte {
-
 	res, body := checkGet(t, ts, path)
 
 	if res.StatusCode != 200 {
diff --git a/probe/docker_process_mapper.go b/probe/docker_process_mapper.go
index ed57526c41..941616efb2 100644
--- a/probe/docker_process_mapper.go
+++ b/probe/docker_process_mapper.go
@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"log"
+	"strings"
 	"sync"
 	"time"
 
@@ -135,7 +136,7 @@ func (m *dockerMapper) idMapper() processMapper {
 
 func (m *dockerMapper) nameMapper() processMapper {
 	return &dockerProcessMapper{m, "docker_name", func(c *docker.Container) string {
-		return c.Name
+		return strings.TrimPrefix(c.Name, "/")
 	}}
 }
 
diff --git a/report/mapping_functions.go b/report/mapping_functions.go
index 2a206db09e..1b20108f5d 100644
--- a/report/mapping_functions.go
+++ b/report/mapping_functions.go
@@ -48,6 +48,37 @@ func ProcessPID(_ string, m NodeMetadata, grouped bool) (MappedNode, bool) {
 	}, show
 }
 
+// ProcessContainer maps Process topology nodes to the containers they run in.
+// We consider container and image IDs to be globally unique, and so don't
+// scope them further by e.g. host. If no container metadata is found, nodes
+// are grouped into the Uncontained node. If grouped is true, nodes with the
+// same container image ID are merged together.
+func ProcessContainer(_ string, m NodeMetadata, grouped bool) (MappedNode, bool) {
+	var (
+		containerID   = m["docker_id"]
+		containerName = m["docker_name"]
+		imageID       = m["docker_image_id"]
+		imageName     = m["docker_image_name"]
+		domain        = m["domain"]
+	)
+
+	var id, major, minor, rank string
+	if containerID == "" {
+		id, major, minor, rank = "uncontained", "Uncontained", "", "uncontained"
+	} else if grouped {
+		id, major, minor, rank = imageID, imageName, "", imageID
+	} else {
+		id, major, minor, rank = containerID, containerName, domain, imageID
+	}
+
+	return MappedNode{
+		ID:    id,
+		Major: major,
+		Minor: minor,
+		Rank:  rank,
+	}, true
+}
+
 // NetworkHostname takes a node NodeMetadata from a Network topology, and
 // returns a representation based on the hostname. Major label is the
 // hostname, the minor label is the domain, if any.
diff --git a/report/mapping_test.go b/report/mapping_test.go
index bb3ed957e9..7f3ca11718 100644
--- a/report/mapping_test.go
+++ b/report/mapping_test.go
@@ -51,6 +51,38 @@ func TestUngroupedMapping(t *testing.T) {
 			wantMinor: "hosta (42)",
 			wantRank:  "42",
 		},
+		{
+			f:  ProcessContainer,
+			id: "foo-id",
+			meta: NodeMetadata{
+				"pid":    "42",
+				"name":   "curl",
+				"domain": "hosta",
+			},
+			wantOK:    true,
+			wantID:    "uncontained",
+			wantMajor: "Uncontained",
+			wantMinor: "",
+			wantRank:  "uncontained",
+		},
+		{
+			f:  ProcessContainer,
+			id: "bar-id",
+			meta: NodeMetadata{
+				"pid":               "42",
+				"name":              "curl",
+				"domain":            "hosta",
+				"docker_id":         "d321fe0",
+				"docker_name":       "walking_sparrow",
+				"docker_image_id":   "1101fff",
+				"docker_image_name": "org/app:latest",
+			},
+			wantOK:    true,
+			wantID:    "d321fe0",
+			wantMajor: "walking_sparrow",
+			wantMinor: "hosta",
+			wantRank:  "1101fff",
+		},
 	} {
 		identity := fmt.Sprintf("(%d %s %v)", i, c.id, c.meta)