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_status.go

@@ -0,0 +1,166 @@
+// 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"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"path"
+
+	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	ilm_statuses = []string{"STOPPED", "RUNNING", "STOPPING"}
+)
+
+type ilmStatusMetric struct {
+	Type   prometheus.ValueType
+	Desc   *prometheus.Desc
+	Value  func(ilm *IlmStatusResponse, status string) float64
+	Labels func(status string) []string
+}
+
+// IlmStatusCollector information struct
+type IlmStatusCollector struct {
+	logger log.Logger
+	client *http.Client
+	url    *url.URL
+
+	up                              prometheus.Gauge
+	totalScrapes, jsonParseFailures prometheus.Counter
+
+	metric ilmStatusMetric
+}
+
+// NewIlmStatus defines Indices IndexIlms Prometheus metrics
+func NewIlmStatus(logger log.Logger, client *http.Client, url *url.URL) *IlmStatusCollector {
+	subsystem := "ilm"
+
+	return &IlmStatusCollector{
+		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 Indices Ilms endpoint successful.",
+		}),
+		totalScrapes: prometheus.NewCounter(prometheus.CounterOpts{
+			Name: prometheus.BuildFQName(namespace, subsystem, "scrapes_total"),
+			Help: "Current total ElasticSearch Indices Ilms scrapes.",
+		}),
+		jsonParseFailures: prometheus.NewCounter(prometheus.CounterOpts{
+			Name: prometheus.BuildFQName(namespace, subsystem, "json_parse_failures_total"),
+			Help: "Number of errors while parsing JSON.",
+		}),
+		metric: ilmStatusMetric{
+			Type: prometheus.GaugeValue,
+			Desc: prometheus.NewDesc(
+				prometheus.BuildFQName(namespace, subsystem, "status"),
+				"Current status of ilm. Status can be STOPPED, RUNNING, STOPPING.",
+				ilm_statuses, nil,
+			),
+			Value: func(ilm *IlmStatusResponse, status string) float64 {
+				if ilm.OperationMode == status {
+					return 1
+				}
+				return 0
+			},
+		},
+	}
+}
+
+// Describe add Snapshots metrics descriptions
+func (im *IlmStatusCollector) Describe(ch chan<- *prometheus.Desc) {
+	ch <- im.metric.Desc
+	ch <- im.up.Desc()
+	ch <- im.totalScrapes.Desc()
+	ch <- im.jsonParseFailures.Desc()
+}
+
+func (im *IlmStatusCollector) getAndParseURL(u *url.URL) (*IlmStatusResponse, error) {
+	res, err := im.client.Get(u.String())
+	if err != nil {
+		return nil, fmt.Errorf("failed to get from %s://%s:%s%s: %s",
+			u.Scheme, u.Hostname(), u.Port(), u.Path, err)
+	}
+
+	if res.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("HTTP Request failed with code %d", res.StatusCode)
+	}
+
+	body, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		_ = level.Warn(im.logger).Log("msg", "failed to read response body", "err", err)
+		return nil, err
+	}
+
+	err = res.Body.Close()
+	if err != nil {
+		_ = level.Warn(im.logger).Log("msg", "failed to close response body", "err", err)
+		return nil, err
+	}
+
+	var imr IlmStatusResponse
+	if err := json.Unmarshal(body, &imr); err != nil {
+		im.jsonParseFailures.Inc()
+		return nil, err
+	}
+
+	return &imr, nil
+}
+
+func (im *IlmStatusCollector) fetchAndDecodeIlm() (*IlmStatusResponse, error) {
+	u := *im.url
+	u.Path = path.Join(u.Path, "/_ilm/status")
+	return im.getAndParseURL(&u)
+}
+
+// Collect gets all indices Ilms metric values
+func (im *IlmStatusCollector) Collect(ch chan<- prometheus.Metric) {
+
+	im.totalScrapes.Inc()
+	defer func() {
+		ch <- im.up
+		ch <- im.totalScrapes
+		ch <- im.jsonParseFailures
+	}()
+
+	indicesIlmsResponse, err := im.fetchAndDecodeIlm()
+	if err != nil {
+		im.up.Set(0)
+		_ = level.Warn(im.logger).Log(
+			"msg", "failed to fetch and decode cluster ilm status",
+			"err", err,
+		)
+		return
+	}
+	im.up.Set(1)
+
+	for _, status := range ilm_statuses {
+		ch <- prometheus.MustNewConstMetric(
+			im.metric.Desc,
+			im.metric.Type,
+			im.metric.Value(indicesIlmsResponse, status),
+			status,
+		)
+	}
+
+}

collector/ilm_status_response.go

@@ -0,0 +1,19 @@
+// 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
+
+// IlmStatusResponse is a representation of elasticsearch ilm status
+type IlmStatusResponse struct {
+	OperationMode string `json:"operation_mode"`
+}