Add ability to filter triton_sd targets by pre-defined groups (#4701)

Additionally, add triton groups metadata to the discovery reponse
and correct a documentation error regarding the triton server id
metadata.

Signed-off-by: Richard Kiene <richard.kiene@joyent.com>

discovery/triton/triton.go

@@ -19,6 +19,8 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"net/url"
+	"strings"
 	"time"
 
 	"github.com/go-kit/kit/log"
@@ -33,6 +35,7 @@ import (
 
 const (
 	tritonLabel             = model.MetaLabelPrefix + "triton_"
+	tritonLabelGroups       = tritonLabel + "groups"
 	tritonLabelMachineID    = tritonLabel + "machine_id"
 	tritonLabelMachineAlias = tritonLabel + "machine_alias"
 	tritonLabelMachineBrand = tritonLabel + "machine_brand"
@@ -65,6 +68,7 @@ type SDConfig struct {
 	Account         string                `yaml:"account"`
 	DNSSuffix       string                `yaml:"dns_suffix"`
 	Endpoint        string                `yaml:"endpoint"`
+	Groups          []string              `yaml:"groups,omitempty"`
 	Port            int                   `yaml:"port"`
 	RefreshInterval model.Duration        `yaml:"refresh_interval,omitempty"`
 	TLSConfig       config_util.TLSConfig `yaml:"tls_config,omitempty"`
@@ -102,11 +106,12 @@ func init() {
 // DiscoveryResponse models a JSON response from the Triton discovery.
 type DiscoveryResponse struct {
 	Containers []struct {
-		ServerUUID  string `json:"server_uuid"`
+		Groups      []string `json:"groups"`
-		VMAlias     string `json:"vm_alias"`
+		ServerUUID  string   `json:"server_uuid"`
-		VMBrand     string `json:"vm_brand"`
+		VMAlias     string   `json:"vm_alias"`
-		VMImageUUID string `json:"vm_image_uuid"`
+		VMBrand     string   `json:"vm_brand"`
-		VMUUID      string `json:"vm_uuid"`
+		VMImageUUID string   `json:"vm_image_uuid"`
+		VMUUID      string   `json:"vm_uuid"`
 	} `json:"containers"`
 }
 
@@ -187,6 +192,11 @@ func (d *Discovery) refresh() (tg *targetgroup.Group, err error) {
 	}()
 
 	var endpoint = fmt.Sprintf("https://%s:%d/v%d/discover", d.sdConfig.Endpoint, d.sdConfig.Port, d.sdConfig.Version)
+	if len(d.sdConfig.Groups) > 0 {
+		groups := url.QueryEscape(strings.Join(d.sdConfig.Groups, ","))
+		endpoint = fmt.Sprintf("%s?groups=%s", endpoint, groups)
+	}
+
 	tg = &targetgroup.Group{
 		Source: endpoint,
 	}
@@ -219,6 +229,12 @@ func (d *Discovery) refresh() (tg *targetgroup.Group, err error) {
 		}
 		addr := fmt.Sprintf("%s.%s:%d", container.VMUUID, d.sdConfig.DNSSuffix, d.sdConfig.Port)
 		labels[model.AddressLabel] = model.LabelValue(addr)
+
+		if len(container.Groups) > 0 {
+			name := "," + strings.Join(container.Groups, ",") + ","
+			labels[tritonLabelGroups] = model.LabelValue(name)
+		}
+
 		tg.Targets = append(tg.Targets, labels)
 	}
 

discovery/triton/triton_test.go

@@ -55,6 +55,16 @@ var (
 			CertFile:           "shouldnotexist.cert",
 		},
 	}
+	groupsconf = SDConfig{
+		Account:         "testAccount",
+		DNSSuffix:       "triton.example.com",
+		Endpoint:        "127.0.0.1",
+		Groups:          []string{"foo", "bar"},
+		Port:            443,
+		Version:         1,
+		RefreshInterval: 1,
+		TLSConfig:       config.TLSConfig{InsecureSkipVerify: true},
+	}
 )
 
 func TestTritonSDNew(t *testing.T) {
@@ -76,6 +86,20 @@ func TestTritonSDNewBadConfig(t *testing.T) {
 	testutil.Assert(t, td == nil, "")
 }
 
+func TestTritonSDNewGroupsConfig(t *testing.T) {
+	td, err := New(nil, &groupsconf)
+	testutil.Ok(t, err)
+	testutil.Assert(t, td != nil, "")
+	testutil.Assert(t, td.client != nil, "")
+	testutil.Assert(t, td.interval != 0, "")
+	testutil.Assert(t, td.sdConfig != nil, "")
+	testutil.Equals(t, groupsconf.Account, td.sdConfig.Account)
+	testutil.Equals(t, groupsconf.DNSSuffix, td.sdConfig.DNSSuffix)
+	testutil.Equals(t, groupsconf.Endpoint, td.sdConfig.Endpoint)
+	testutil.Equals(t, groupsconf.Groups, td.sdConfig.Groups)
+	testutil.Equals(t, groupsconf.Port, td.sdConfig.Port)
+}
+
 func TestTritonSDRun(t *testing.T) {
 	var (
 		td, err     = New(nil, &conf)
@@ -112,6 +136,7 @@ func TestTritonSDRefreshMultipleTargets(t *testing.T) {
 	var (
 		dstr = `{"containers":[
 		 	{
+                                "groups":["foo","bar","baz"],
 				"server_uuid":"44454c4c-5000-104d-8037-b7c04f5a5131",
 				"vm_alias":"server01",
 				"vm_brand":"lx",

docs/configuration/configuration.md

@@ -935,10 +935,12 @@ discovery endpoints.
 
 The following meta labels are available on targets during relabeling:
 
-* `__meta_triton_machine_id`: the UUID of the target container
+* `__meta_triton_groups`: the list of groups belonging to the target joined by a comma separator
 * `__meta_triton_machine_alias`: the alias of the target container
+* `__meta_triton_machine_brand`: the brand of the target container
+* `__meta_triton_machine_id`: the UUID of the target container
 * `__meta_triton_machine_image`: the target containers image type
-* `__meta_triton_machine_server_id`: the server UUID for the target container
+* `__meta_triton_server_id`: the server UUID for the target container
 
 ```yaml
 # The information to access the Triton discovery API.
@@ -953,6 +955,11 @@ dns_suffix: <string>
 # often the same value as dns_suffix.
 endpoint: <string>
 
+# A list of groups for which targets are retrieved. If omitted, all containers
+# available to the requesting account are scraped.
+groups: 
+  [ - <string> ... ]
+
 # The port to use for discovery and metric scraping.
 [ port: <int> | default = 9163 ]