feat(*): add ilm metrics

Signed-off-by: iishabakaev <iishabakaev@gmail.com>

collector/ilm_indices.go

@@ -0,0 +1,164 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package collector
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"path"
+
+	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type ilmMetric struct {
+	Type   prometheus.ValueType
+	Desc   *prometheus.Desc
+	Value  func(timeMillis float64) float64
+	Labels []string
+}
+
+// Index Lifecycle Management information object
+type IlmIndiciesCollector struct {
+	logger log.Logger
+	client *http.Client
+	url    *url.URL
+
+	up                prometheus.Gauge
+	totalScrapes      prometheus.Counter
+	jsonParseFailures prometheus.Counter
+
+	ilmMetric ilmMetric
+}
+
+var (
+	defaultIlmIndicesMappingsLabels = []string{"index", "phase", "action", "step"}
+)
+
+// NewIlmIndicies defines Index Lifecycle Management Prometheus metrics
+func NewIlmIndicies(logger log.Logger, client *http.Client, url *url.URL) *IlmIndiciesCollector {
+	subsystem := "ilm_index"
+
+	return &IlmIndiciesCollector{
+		logger: logger,
+		client: client,
+		url:    url,
+
+		up: prometheus.NewGauge(prometheus.GaugeOpts{
+			Name: prometheus.BuildFQName(namespace, subsystem, "up"),
+			Help: "Was the last scrape of the ElasticSearch ILM endpoint successful.",
+		}),
+		totalScrapes: prometheus.NewCounter(prometheus.CounterOpts{
+			Name: prometheus.BuildFQName(namespace, subsystem, "total_scrapes"),
+			Help: "Current total ElasticSearch ILM scrapes.",
+		}),
+		jsonParseFailures: prometheus.NewCounter(prometheus.CounterOpts{
+			Name: prometheus.BuildFQName(namespace, subsystem, "json_parse_failures"),
+			Help: "Number of errors while parsing JSON.",
+		}),
+		ilmMetric: ilmMetric{
+			Type: prometheus.GaugeValue,
+			Desc: prometheus.NewDesc(
+				prometheus.BuildFQName(namespace, subsystem, "status"),
+				"Status of ILM policy for index",
+				defaultIlmIndicesMappingsLabels, nil),
+			Value: func(timeMillis float64) float64 {
+				return timeMillis
+			},
+		},
+	}
+}
+
+// Describe adds metrics description
+func (i *IlmIndiciesCollector) Describe(ch chan<- *prometheus.Desc) {
+	ch <- i.ilmMetric.Desc
+	ch <- i.up.Desc()
+	ch <- i.totalScrapes.Desc()
+	ch <- i.jsonParseFailures.Desc()
+}
+
+func (i *IlmIndiciesCollector) fetchAndDecodeIlm() (IlmResponse, error) {
+	var ir IlmResponse
+
+	u := *i.url
+	u.Path = path.Join(u.Path, "/_all/_ilm/explain")
+
+	res, err := i.client.Get(u.String())
+	if err != nil {
+		return ir, fmt.Errorf("failed to get index stats from %s://%s:%s%s: %s",
+			u.Scheme, u.Hostname(), u.Port(), u.Path, err)
+	}
+
+	defer func() {
+		err = res.Body.Close()
+		if err != nil {
+			_ = level.Warn(i.logger).Log(
+				"msg", "failed to close http.Client",
+				"err", err,
+			)
+		}
+	}()
+
+	if res.StatusCode != http.StatusOK {
+		return ir, fmt.Errorf("HTTP Request failed with code %d", res.StatusCode)
+	}
+
+	if err := json.NewDecoder(res.Body).Decode(&ir); err != nil {
+		i.jsonParseFailures.Inc()
+		return ir, err
+	}
+
+	return ir, nil
+}
+
+func bool2int(managed bool) float64 {
+	if managed {
+		return 1
+	}
+	return 0
+}
+
+// Collect pulls metric values from Elasticsearch
+func (i *IlmIndiciesCollector) Collect(ch chan<- prometheus.Metric) {
+	defer func() {
+		ch <- i.up
+		ch <- i.totalScrapes
+		ch <- i.jsonParseFailures
+	}()
+
+	// indices
+	ilmResp, err := i.fetchAndDecodeIlm()
+	if err != nil {
+		i.up.Set(0)
+		_ = level.Warn(i.logger).Log(
+			"msg", "failed to fetch and decode ILM stats",
+			"err", err,
+		)
+		return
+	}
+	i.totalScrapes.Inc()
+	i.up.Set(1)
+
+	for indexName, indexIlm := range ilmResp.Indices {
+		ch <- prometheus.MustNewConstMetric(
+			i.ilmMetric.Desc,
+			i.ilmMetric.Type,
+			i.ilmMetric.Value(bool2int(indexIlm.Managed)),
+			indexName, indexIlm.Phase, indexIlm.Action, indexIlm.Step,
+		)
+	}
+}

collector/ilm_indices_response.go

@@ -0,0 +1,27 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package collector
+
+type IlmResponse struct {
+	Indices map[string]IlmIndexResponse `json:"indices"`
+}
+
+type IlmIndexResponse struct {
+	Index          string  `json:"index"`
+	Managed        bool    `json:"managed"`
+	Phase          string  `json:"phase"`
+	Action         string  `json:"action"`
+	Step           string  `json:"step"`
+	StepTimeMillis float64 `json:"step_time_millis"`
+}

collector/ilm_indices_test.go

@@ -0,0 +1,117 @@
+// Copyright 2021 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package collector
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	"github.com/go-kit/log"
+)
+
+func TestILMMetrics(t *testing.T) {
+	// Testcases created using:
+	//  docker run -d -p 9200:9200 elasticsearch:VERSION
+	//  curl -XPUT http://localhost:9200/twitter
+	// 	curl -X PUT "localhost:9200/_ilm/policy/my_policy?pretty" -H 'Content-Type: application/json' -d'
+	// 	{
+	// 	  "policy": {
+	// 		"phases": {
+	// 		  "warm": {
+	// 			"min_age": "10d",
+	// 			"actions": {
+	// 			  "forcemerge": {
+	// 				"max_num_segments": 1
+	// 			  }
+	// 			}
+	// 		  },
+	// 		  "delete": {
+	// 			"min_age": "30d",
+	// 			"actions": {
+	// 			  "delete": {}
+	// 			}
+	// 		  }
+	// 		}
+	// 	  }
+	// 	}
+	// 	'
+	// 	curl -X PUT "localhost:9200/facebook?pretty" -H 'Content-Type: application/json' -d'
+	// 	{
+	// 	"settings": {
+	// 		"index": {
+	// 		"lifecycle": {
+	// 			"name": "my_policy"
+	// 		}
+	// 		}
+	// 	}
+	// 	}
+	// 	'
+	//  curl http://localhost:9200/_all/_ilm/explain
+	tcs := map[string]string{
+		"6.6.0": `{
+			"indices": {
+			  "twitter": { "index": "twitter", "managed": false },
+			  "facebook": {
+				"index": "facebook",
+				"managed": true,
+				"policy": "my_policy",
+				"lifecycle_date_millis": 1660799138565,
+				"phase": "new",
+				"phase_time_millis": 1660799138651,
+				"action": "complete",
+				"action_time_millis": 1660799138651,
+				"step": "complete",
+				"step_time_millis": 1660799138651
+			  }
+			}
+		  }`,
+	}
+	for ver, out := range tcs {
+		ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			fmt.Fprintln(w, out)
+		}))
+		defer ts.Close()
+
+		u, err := url.Parse(ts.URL)
+		if err != nil {
+			t.Fatalf("Failed to parse URL: %s", err)
+		}
+		c := NewIlmIndicies(log.NewNopLogger(), http.DefaultClient, u)
+		chr, err := c.fetchAndDecodeIlm()
+		if err != nil {
+			t.Fatalf("Failed to fetch or decode indices ilm metrics: %s", err)
+		}
+		t.Logf("[%s] indices ilm metrics Response: %+v", ver, chr)
+
+		if chr.Indices["twitter"].Managed != false {
+			t.Errorf("Invalid ilm metrics at twitter.managed")
+		}
+		if chr.Indices["facebook"].Managed != true {
+			t.Errorf("Invalid ilm metrics at facebook.managed")
+		}
+		if chr.Indices["facebook"].Phase != "new" {
+			t.Errorf("Invalid ilm metrics at facebook.phase")
+		}
+		if chr.Indices["facebook"].Action != "complete" {
+			t.Errorf("Invalid ilm metrics at facebook.action")
+		}
+		if chr.Indices["facebook"].Step != "complete" {
+			t.Errorf("Invalid ilm metrics at facebook.step")
+		}
+
+	}
+}