From cd0702e2ba93ddfa540adc68edbece5eeef34af9 Mon Sep 17 00:00:00 2001
From: rsingh2411 <singh.rohit2411@gmail.com>
Date: Tue, 28 Mar 2017 10:11:18 +0000
Subject: [PATCH] Add Docker container environment variables as tags. Only
 whitelisted #2580

---
 plugins/inputs/docker/docker.go      | 41 ++++++++++++++++++++++++----
 plugins/inputs/docker/docker_test.go |  9 ++++--
 plugins/inputs/docker/fake_client.go | 15 ++++++++++
 3 files changed, 58 insertions(+), 7 deletions(-)

diff --git a/plugins/inputs/docker/docker.go b/plugins/inputs/docker/docker.go
index ec192efd5e5d3..9b159de60640c 100644
--- a/plugins/inputs/docker/docker.go
+++ b/plugins/inputs/docker/docker.go
@@ -22,11 +22,12 @@ import (
 
 // Docker object
 type Docker struct {
-	Endpoint       string
-	ContainerNames []string
-	Timeout        internal.Duration
-	PerDevice      bool `toml:"perdevice"`
-	Total          bool `toml:"total"`
+	Endpoint          string
+	ContainerNames    []string
+	Timeout           internal.Duration
+	PerDevice         bool     `toml:"perdevice"`
+	Total             bool     `toml:"total"`
+	GatherEnvironment []string `toml:"gather_environment"`
 
 	client      *client.Client
 	engine_host string
@@ -70,6 +71,18 @@ func statsWrapper(
 	return fc.ContainerStats(ctx, containerID, stream)
 }
 
+func inspectWrapper(
+	c *client.Client,
+	ctx context.Context,
+	containerID string,
+) (types.ContainerJSON, error) {
+	if c != nil {
+		return c.ContainerInspect(ctx, containerID)
+	}
+	fc := FakeDockerClient{}
+	return fc.ContainerInspect(ctx, containerID)
+}
+
 // KB, MB, GB, TB, PB...human friendly
 const (
 	KB = 1000
@@ -98,6 +111,8 @@ var sampleConfig = `
   perdevice = true
   ## Whether to report for each container total blkio and network stats or not
   total = false
+  ## Which environment variables should we use as a tag
+  gather_environment = ["ENV", "DC"]
 
 `
 
@@ -296,6 +311,22 @@ func (d *Docker) gatherContainer(
 		tags[k] = label
 	}
 
+	// Add whitelisted environment variables to tags
+	if len(d.GatherEnvironment) > 0 {
+		info, err := inspectWrapper(d.client, ctx, container.ID)
+		if err != nil {
+			return fmt.Errorf("Error getting docker container inspect: %s", err.Error())
+		}
+
+		for _, envvar := range info.Config.Env {
+			kvs := strings.SplitN(envvar, "=", 2)
+			if !sliceContains(kvs[0], d.GatherEnvironment) {
+				continue
+			}
+			tags[kvs[0]] = kvs[1]
+		}
+	}
+
 	gatherContainerStats(v, acc, tags, container.ID, d.PerDevice, d.Total)
 
 	return nil
diff --git a/plugins/inputs/docker/docker_test.go b/plugins/inputs/docker/docker_test.go
index f0add03ea20c4..712288654e897 100644
--- a/plugins/inputs/docker/docker_test.go
+++ b/plugins/inputs/docker/docker_test.go
@@ -247,8 +247,9 @@ func testStats() *types.StatsJSON {
 func TestDockerGatherInfo(t *testing.T) {
 	var acc testutil.Accumulator
 	d := Docker{
-		client:  nil,
-		testing: true,
+		client:            nil,
+		testing:           true,
+		GatherEnvironment: []string{"ENVVAR1", "ENVVAR2"},
 	}
 
 	err := d.Gather(&acc)
@@ -294,6 +295,8 @@ func TestDockerGatherInfo(t *testing.T) {
 			"cpu":               "cpu3",
 			"container_version": "v2.2.2",
 			"engine_host":       "absol",
+			"ENVVAR1":           "loremipsum",
+			"ENVVAR2":           "dolorsitamet",
 		},
 	)
 	acc.AssertContainsTaggedFields(t,
@@ -340,6 +343,8 @@ func TestDockerGatherInfo(t *testing.T) {
 			"container_name":    "etcd2",
 			"container_image":   "quay.io:4443/coreos/etcd",
 			"container_version": "v2.2.2",
+			"ENVVAR1":           "loremipsum",
+			"ENVVAR2":           "dolorsitamet",
 		},
 	)
 
diff --git a/plugins/inputs/docker/fake_client.go b/plugins/inputs/docker/fake_client.go
index 03da23198a890..6e2a2d4ec06de 100644
--- a/plugins/inputs/docker/fake_client.go
+++ b/plugins/inputs/docker/fake_client.go
@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/registry"
 )
 
@@ -141,3 +142,17 @@ func (d FakeDockerClient) ContainerStats(ctx context.Context, containerID string
 	stat.Body = ioutil.NopCloser(strings.NewReader(jsonStat))
 	return stat, nil
 }
+
+func (d FakeDockerClient) ContainerInspect(ctx context.Context, containerID string) (types.ContainerJSON, error) {
+	json := types.ContainerJSON{
+		Config: &container.Config{
+			Env: []string{
+				"ENVVAR1=loremipsum",
+				"ENVVAR2=dolorsitamet",
+				"PATH=/bin:/sbin",
+			},
+		},
+	}
+
+	return json, nil
+}