Merge pull request prometheus#2234 from brancz/targets-api

web/api: add targets endpoint
chowdhary987 · Dec 5, 2016 · 0459dcd · 0459dcd
2 parents 63fe65b + 33b583d
commit 0459dcd
Showing 7 changed files with 154 additions and 74 deletions.
diff --git a/retrieval/target.go b/retrieval/target.go
@@ -45,7 +45,7 @@ const (
 // Target refers to a singular HTTP or HTTPS endpoint.
 type Target struct {
 	// Labels before any processing.
-	metaLabels model.LabelSet
+	discoveredLabels model.LabelSet
 	// Any labels that are added to this target and its metrics.
 	labels model.LabelSet
 	// Additional URL parmeters that are part of the target URL.
@@ -58,12 +58,12 @@ type Target struct {
 }
 
 // NewTarget creates a reasonably configured target for querying.
-func NewTarget(labels, metaLabels model.LabelSet, params url.Values) *Target {
+func NewTarget(labels, discoveredLabels model.LabelSet, params url.Values) *Target {
 	return &Target{
-		labels:     labels,
-		metaLabels: metaLabels,
-		params:     params,
-		health:     HealthUnknown,
+		labels:           labels,
+		discoveredLabels: discoveredLabels,
+		params:           params,
+		health:           HealthUnknown,
 	}
 }
 
@@ -144,9 +144,9 @@ func (t *Target) Labels() model.LabelSet {
 	return lset
 }
 
-// MetaLabels returns a copy of the target's labels before any processing.
-func (t *Target) MetaLabels() model.LabelSet {
-	return t.metaLabels.Clone()
+// DiscoveredLabels returns a copy of the target's labels before any processing.
+func (t *Target) DiscoveredLabels() model.LabelSet {
+	return t.discoveredLabels.Clone()
 }
 
 // URL returns a copy of the target's URL.

diff --git a/retrieval/targetmanager.go b/retrieval/targetmanager.go
@@ -14,11 +14,9 @@
 package retrieval
 
 import (
-	"sort"
 	"sync"
 
 	"github.com/prometheus/common/log"
-	"github.com/prometheus/common/model"
 	"golang.org/x/net/context"
 
 	"github.com/prometheus/prometheus/config"
@@ -133,28 +131,23 @@ func (tm *TargetManager) reload() {
 	}
 }
 
-// Pools returns the targets currently being scraped bucketed by their job name.
-func (tm *TargetManager) Pools() map[string]Targets {
+// Targets returns the targets currently being scraped bucketed by their job name.
+func (tm *TargetManager) Targets() []Target {
 	tm.mtx.RLock()
 	defer tm.mtx.RUnlock()
 
-	pools := map[string]Targets{}
-
-	// TODO(fabxc): this is just a hack to maintain compatibility for now.
+	targets := []Target{}
 	for _, ps := range tm.targetSets {
 		ps.sp.mtx.RLock()
 
 		for _, t := range ps.sp.targets {
-			job := string(t.Labels()[model.JobLabel])
-			pools[job] = append(pools[job], t)
+			targets = append(targets, *t)
 		}
 
 		ps.sp.mtx.RUnlock()
 	}
-	for _, targets := range pools {
-		sort.Sort(targets)
-	}
-	return pools
+
+	return targets
 }
 
 // ApplyConfig resets the manager's target providers and job configurations as defined

diff --git a/web/api/v1/api.go b/web/api/v1/api.go
@@ -28,6 +28,7 @@ import (
 	"golang.org/x/net/context"
 
 	"github.com/prometheus/prometheus/promql"
+	"github.com/prometheus/prometheus/retrieval"
 	"github.com/prometheus/prometheus/storage/local"
 	"github.com/prometheus/prometheus/storage/metric"
 	"github.com/prometheus/prometheus/util/httputil"
@@ -66,6 +67,10 @@ func (e *apiError) Error() string {
 	return fmt.Sprintf("%s: %s", e.typ, e.err)
 }
 
+type targetRetriever interface {
+	Targets() []retrieval.Target
+}
+
 type response struct {
 	Status    status      `json:"status"`
 	Data      interface{} `json:"data,omitempty"`
@@ -88,17 +93,20 @@ type API struct {
 	Storage     local.Storage
 	QueryEngine *promql.Engine
 
+	targetRetriever targetRetriever
+
 	context func(r *http.Request) context.Context
 	now     func() model.Time
 }
 
 // NewAPI returns an initialized API type.
-func NewAPI(qe *promql.Engine, st local.Storage) *API {
+func NewAPI(qe *promql.Engine, st local.Storage, tr targetRetriever) *API {
 	return &API{
-		QueryEngine: qe,
-		Storage:     st,
-		context:     route.Context,
-		now:         model.Now,
+		QueryEngine:     qe,
+		Storage:         st,
+		targetRetriever: tr,
+		context:         route.Context,
+		now:             model.Now,
 	}
 }
 
@@ -129,6 +137,8 @@ func (api *API) Register(r *route.Router) {
 
 	r.Get("/series", instr("series", api.series))
 	r.Del("/series", instr("drop_series", api.dropSeries))
+
+	r.Get("/targets", instr("targets", api.targets))
 }
 
 type queryData struct {
@@ -328,6 +338,43 @@ func (api *API) dropSeries(r *http.Request) (interface{}, *apiError) {
 	return res, nil
 }
 
+type Target struct {
+	// Labels before any processing.
+	DiscoveredLabels model.LabelSet `json:"discoveredLabels"`
+	// Any labels that are added to this target and its metrics.
+	Labels model.LabelSet `json:"labels"`
+
+	ScrapeUrl string `json:"scrapeUrl"`
+
+	LastError  string                 `json:"lastError"`
+	LastScrape time.Time              `json:"lastScrape"`
+	Health     retrieval.TargetHealth `json:"health"`
+}
+
+func (api *API) targets(r *http.Request) (interface{}, *apiError) {
+	targets := api.targetRetriever.Targets()
+	res := make([]*Target, len(targets))
+
+	for i, t := range targets {
+		lastErrStr := ""
+		lastErr := t.LastError()
+		if lastErr != nil {
+			lastErrStr = lastErr.Error()
+		}
+
+		res[i] = &Target{
+			DiscoveredLabels: t.DiscoveredLabels(),
+			Labels:           t.Labels(),
+			ScrapeUrl:        t.URL().String(),
+			LastError:        lastErrStr,
+			LastScrape:       t.LastScrape(),
+			Health:           t.Health(),
+		}
+	}
+
+	return res, nil
+}
+
 func respond(w http.ResponseWriter, data interface{}) {
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(http.StatusOK)

diff --git a/web/api/v1/api_test.go b/web/api/v1/api_test.go
@@ -30,8 +30,15 @@ import (
 	"golang.org/x/net/context"
 
 	"github.com/prometheus/prometheus/promql"
+	"github.com/prometheus/prometheus/retrieval"
 )
 
+type targetRetrieverFunc func() []retrieval.Target
+
+func (f targetRetrieverFunc) Targets() []retrieval.Target {
+	return f()
+}
+
 func TestEndpoints(t *testing.T) {
 	suite, err := promql.NewTest(t, `
 		load 1m
@@ -49,10 +56,26 @@ func TestEndpoints(t *testing.T) {
 	}
 
 	now := model.Now()
+
+	tr := targetRetrieverFunc(func() []retrieval.Target {
+		return []retrieval.Target{
+			*retrieval.NewTarget(
+				model.LabelSet{
+					model.SchemeLabel:      "http",
+					model.AddressLabel:     "example.com:8080",
+					model.MetricsPathLabel: "/metrics",
+				},
+				model.LabelSet{},
+				url.Values{},
+			),
+		}
+	})
+
 	api := &API{
-		Storage:     suite.Storage(),
-		QueryEngine: suite.QueryEngine(),
-		now:         func() model.Time { return now },
+		Storage:         suite.Storage(),
+		QueryEngine:     suite.QueryEngine(),
+		targetRetriever: tr,
+		now:             func() model.Time { return now },
 	}
 
 	start := model.Time(0)
@@ -404,6 +427,16 @@ func TestEndpoints(t *testing.T) {
 			response: struct {
 				NumDeleted int `json:"numDeleted"`
 			}{2},
+		}, {
+			endpoint: api.targets,
+			response: []*Target{
+				&Target{
+					DiscoveredLabels: model.LabelSet{},
+					Labels:           model.LabelSet{},
+					ScrapeUrl:        "http://example.com:8080/metrics",
+					Health:           "unknown",
+				},
+			},
 		},
 	}