Refactor ILM collector (#999)

* Refactor ILM collector

Consolidate the ILM collector logic into a single collector using the new Collector interface

Signed-off-by: Joe Adams <[email protected]>

Author: sysadmind

CHANGELOG.md

@@ -3,8 +3,10 @@
 BREAKING CHANGES:
 
 The flag `--es.data_stream` has been renamed to `--collector.data-stream`.
+The flag `--es.ilm` has been renamed to `--collector.ilm`.
 
 * [CHANGE] Rename --es.data_stream to --collector.data-stream #983
+* [CHANGE] Rename --es.ilm to --collector.ilm #999
 
 ## 1.9.0 / 2025-02-27
 

collector/ilm.go

@@ -0,0 +1,129 @@
+// Copyright 2025 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 (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"net/url"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	ilmStatusOptions = []string{"STOPPED", "RUNNING", "STOPPING"}
+
+	ilmIndexStatus = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "ilm_index", "status"),
+		"Status of ILM policy for index",
+		[]string{"index", "phase", "action", "step"}, nil)
+
+	ilmStatus = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "ilm", "status"),
+		"Current status of ILM. Status can be STOPPED, RUNNING, STOPPING.",
+		[]string{"operation_mode"}, nil,
+	)
+)
+
+func init() {
+	registerCollector("ilm", defaultDisabled, NewILM)
+}
+
+type ILM struct {
+	logger *slog.Logger
+	hc     *http.Client
+	u      *url.URL
+}
+
+func NewILM(logger *slog.Logger, u *url.URL, hc *http.Client) (Collector, error) {
+	return &ILM{
+		logger: logger,
+		hc:     hc,
+		u:      u,
+	}, nil
+}
+
+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"`
+}
+
+type IlmStatusResponse struct {
+	OperationMode string `json:"operation_mode"`
+}
+
+func (i *ILM) Update(ctx context.Context, ch chan<- prometheus.Metric) error {
+	var ir IlmResponse
+
+	indexURL := i.u.ResolveReference(&url.URL{Path: "/_all/_ilm/explain"})
+
+	indexResp, err := getURL(ctx, i.hc, i.logger, indexURL.String())
+	if err != nil {
+		return fmt.Errorf("failed to load ILM url: %w", err)
+	}
+
+	if err := json.Unmarshal(indexResp, &ir); err != nil {
+		return fmt.Errorf("failed to decode JSON body: %w", err)
+	}
+
+	var isr IlmStatusResponse
+
+	indexStatusURL := i.u.ResolveReference(&url.URL{Path: "/_ilm/status"})
+
+	indexStatusResp, err := getURL(ctx, i.hc, i.logger, indexStatusURL.String())
+	if err != nil {
+		return fmt.Errorf("failed to load ILM url: %w", err)
+	}
+
+	if err := json.Unmarshal(indexStatusResp, &isr); err != nil {
+		return fmt.Errorf("failed to decode JSON body: %w", err)
+	}
+
+	for name, ilm := range ir.Indices {
+		ch <- prometheus.MustNewConstMetric(
+			ilmIndexStatus,
+			prometheus.GaugeValue,
+			bool2Float(ilm.Managed),
+			name, ilm.Phase, ilm.Action, ilm.Step,
+		)
+	}
+
+	for _, status := range ilmStatusOptions {
+		statusActive := false
+		if isr.OperationMode == status {
+			statusActive = true
+		}
+
+		ch <- prometheus.MustNewConstMetric(
+			ilmStatus,
+			prometheus.GaugeValue,
+			bool2Float(statusActive),
+			status,
+		)
+
+	}
+
+	return nil
+}