From 63bd8b0206feeccdffcca278b1473028b4a0eec2 Mon Sep 17 00:00:00 2001
From: Tim Scheuermann <tim.scheuermann@msasafety.com>
Date: Wed, 25 May 2016 14:31:44 +0200
Subject: [PATCH] Added container_labels parameter

---
 CHANGELOG.md                    |  1 +
 plugins/inputs/docker/README.md |  3 +++
 plugins/inputs/docker/docker.go | 28 ++++++++++++++++++++++------
 3 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9f34d495b..234f6ab87 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ time before a new metric is included by the plugin.
 
 - [#1247](https://github.com/influxdata/telegraf/pull/1247): rollbar input plugin. Thanks @francois2metz and @cduez!
 - [#1208](https://github.com/influxdata/telegraf/pull/1208): Standardized AWS credentials evaluation & wildcard CloudWatch dimensions. Thanks @johnrengelman!
+- [#1263](https://github.com/influxdata/telegraf/issues/1263): Added container_labels to docker plugin
 
 ### Bugfixes
 
diff --git a/plugins/inputs/docker/README.md b/plugins/inputs/docker/README.md
index 52f9a7adb..bae40aefd 100644
--- a/plugins/inputs/docker/README.md
+++ b/plugins/inputs/docker/README.md
@@ -22,6 +22,9 @@ for the stat structure can be found
   endpoint = "unix:///var/run/docker.sock"
   # Only collect metrics for these containers, collect all if empty
   container_names = []
+  ## Only collect these container labels from docker daemon, collect all if empty but note that
+  ## this will break prometheus output if containers have inconsistent label sets.
+  container_labels = []
 ```
 
 ### Measurements & Fields:
diff --git a/plugins/inputs/docker/docker.go b/plugins/inputs/docker/docker.go
index 0af7820e1..4f1643eb3 100644
--- a/plugins/inputs/docker/docker.go
+++ b/plugins/inputs/docker/docker.go
@@ -22,9 +22,10 @@ import (
 
 // Docker object
 type Docker struct {
-	Endpoint       string
-	ContainerNames []string
-	Timeout        internal.Duration
+	Endpoint        string
+	ContainerNames  []string
+	ContainerLabels []string
+	Timeout         internal.Duration
 
 	client DockerClient
 }
@@ -56,6 +57,9 @@ var sampleConfig = `
   endpoint = "unix:///var/run/docker.sock"
   ## Only collect metrics for these containers, collect all if empty
   container_names = []
+  ## Only collect these container labels from docker daemon, collect all if empty but note that
+  ## this will break prometheus output if containers have inconsistent label sets.
+  container_labels = []
   ## Timeout for docker list, info, and stats commands
   timeout = "5s"
 `
@@ -232,9 +236,21 @@ func (d *Docker) gatherContainer(
 		return fmt.Errorf("Error decoding: %s", err.Error())
 	}
 
-	// Add labels to tags
-	for k, label := range container.Labels {
-		tags[k] = label
+	// Check if there are container labels specified
+	if len(d.ContainerLabels) == 0 {
+		// Add all labels to tags
+		for k, label := range container.Labels {
+			tags[k] = label
+		}
+	} else {
+		// Omit labels not in d.ContainerLabels and add placeholders for missing labels
+		for _, l := range d.ContainerLabels {
+			if label, ok := container.Labels[l]; ok {
+				tags[l] = label
+			} else {
+				tags[l] = "-"
+			}
+		}
 	}
 
 	gatherContainerStats(v, acc, tags, container.ID)