Add support for adding aliases to index and shard stats

Optionally will include aliases in a label to index and shard stats
prometheus-community · May 6, 2022 · 33e11fd · 33e11fd
1 parent e5fb0a3
commit 33e11fd
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Showing 5 changed files with 175 additions and 15 deletions.
diff --git a/README.md b/README.md
@@ -54,6 +54,7 @@ elasticsearch_exporter --help
 | es.indices              | 1.0.2                 | If true, query stats for all indices in the cluster. | false |
 | es.indices_settings     | 1.0.4rc1              | If true, query settings stats for all indices in the cluster. | false |
 | es.indices_mappings     | 1.2.0                 | If true, query stats for mappings of all indices of the cluster. | false |
+| es.aliases              | 1.0.4rc1              | If true, include aliases in label for all index and shard stats. | false |
 | es.shards               | 1.0.3rc1              | If true, query stats for all indices in the cluster, including shard-level stats (implies `es.indices=true`). | false |
 | es.snapshots            | 1.0.4rc1              | If true, query stats for the cluster snapshots. | false |
 | es.timeout              | 1.0.2                 | Timeout for trying to get stats from Elasticsearch. (ex: 20s) | 5s |

diff --git a/collector/indices.go b/collector/indices.go
@@ -20,7 +20,9 @@ import (
 	"net/http"
 	"net/url"
 	"path"
+	"sort"
 	"strconv"
+	"strings"
 
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
@@ -53,6 +55,7 @@ type Indices struct {
 	client          *http.Client
 	url             *url.URL
 	shards          bool
+	aliases         bool
 	clusterInfoCh   chan *clusterinfo.Response
 	lastClusterInfo *clusterinfo.Response
 
@@ -65,10 +68,13 @@ type Indices struct {
 }
 
 // NewIndices defines Indices Prometheus metrics
-func NewIndices(logger log.Logger, client *http.Client, url *url.URL, shards bool) *Indices {
+func NewIndices(logger log.Logger, client *http.Client, url *url.URL, shards bool, aliases bool) *Indices {
 
 	indexLabels := labels{
 		keys: func(...string) []string {
+			if aliases {
+				return []string{"index", "aliases", "cluster"}
+			}
 			return []string{"index", "cluster"}
 		},
 		values: func(lastClusterinfo *clusterinfo.Response, s ...string) []string {
@@ -83,6 +89,9 @@ func NewIndices(logger log.Logger, client *http.Client, url *url.URL, shards boo
 
 	shardLabels := labels{
 		keys: func(...string) []string {
+			if aliases {
+				return []string{"index", "shard", "node", "primary", "aliases", "cluster"}
+			}
 			return []string{"index", "shard", "node", "primary", "cluster"}
 		},
 		values: func(lastClusterinfo *clusterinfo.Response, s ...string) []string {
@@ -100,6 +109,7 @@ func NewIndices(logger log.Logger, client *http.Client, url *url.URL, shards boo
 		client:        client,
 		url:           url,
 		shards:        shards,
+		aliases:       aliases,
 		clusterInfoCh: make(chan *clusterinfo.Response),
 		lastClusterInfo: &clusterinfo.Response{
 			ClusterName: "unknown_cluster",
@@ -1070,9 +1080,63 @@ func (i *Indices) fetchAndDecodeIndexStats() (indexStatsResponse, error) {
 		u.RawQuery = "ignore_unavailable=true"
 	}
 
+	bts, err := i.queryUrl(&u)
+	if err != nil {
+		return isr, err
+	}
+
+	if err := json.Unmarshal(bts, &isr); err != nil {
+		i.jsonParseFailures.Inc()
+		return isr, err
+	}
+
+	if i.aliases {
+		isr.Aliases = map[string][]string{}
+		asr, err := i.fetchAndDecodeAliases()
+		if err != nil {
+			_ = level.Error(i.logger).Log("err", err.Error())
+			return isr, err
+		}
+
+		for indexName, aliases := range asr {
+			var aliasList []string
+			for aliasName, _ := range aliases.Aliases {
+				aliasList = append(aliasList, aliasName)
+			}
+
+			if len(aliasList) > 0 {
+				sort.Strings(aliasList)
+				isr.Aliases[indexName] = aliasList
+			}
+		}
+	}
+
+	return isr, nil
+}
+
+func (i *Indices) fetchAndDecodeAliases() (aliasesResponse, error) {
+	var asr aliasesResponse
+
+	u := *i.url
+	u.Path = path.Join(u.Path, "/_alias")
+
+	bts, err := i.queryUrl(&u)
+	if err != nil {
+		return asr, err
+	}
+
+	if err := json.Unmarshal(bts, &asr); err != nil {
+		i.jsonParseFailures.Inc()
+		return asr, err
+	}
+
+	return asr, nil
+}
+
+func (i *Indices) queryUrl(u *url.URL) ([]byte, error) {
 	res, err := i.client.Get(u.String())
 	if err != nil {
-		return isr, fmt.Errorf("failed to get index stats from %s://%s:%s%s: %s",
+		return []byte{}, fmt.Errorf("failed to get resource from %s://%s:%s%s: %s",
 			u.Scheme, u.Hostname(), u.Port(), u.Path, err)
 	}
 
@@ -1087,21 +1151,15 @@ func (i *Indices) fetchAndDecodeIndexStats() (indexStatsResponse, error) {
 	}()
 
 	if res.StatusCode != http.StatusOK {
-		return isr, fmt.Errorf("HTTP Request failed with code %d", res.StatusCode)
+		return []byte{}, fmt.Errorf("HTTP Request failed with code %d", res.StatusCode)
 	}
 
 	bts, err := ioutil.ReadAll(res.Body)
 	if err != nil {
-		i.jsonParseFailures.Inc()
-		return isr, err
+		return []byte{}, err
 	}
 
-	if err := json.Unmarshal(bts, &isr); err != nil {
-		i.jsonParseFailures.Inc()
-		return isr, err
-	}
-
-	return isr, nil
+	return bts, nil
 }
 
 // Collect gets Indices metric values
@@ -1127,12 +1185,26 @@ func (i *Indices) Collect(ch chan<- prometheus.Metric) {
 
 	// Index stats
 	for indexName, indexStats := range indexStatsResp.Indices {
+		var labelValues []string
+		var aliasesString string
+		if i.aliases {
+			if aliasNames, ok := indexStatsResp.Aliases[indexName]; ok {
+				aliasesString = strings.Join(aliasNames, ",")
+			}
+		}
+
 		for _, metric := range i.indexMetrics {
+			if i.aliases {
+				labelValues = metric.Labels.values(i.lastClusterInfo, indexName, aliasesString)
+			} else {
+				labelValues = metric.Labels.values(i.lastClusterInfo, indexName)
+			}
+
 			ch <- prometheus.MustNewConstMetric(
 				metric.Desc,
 				metric.Type,
 				metric.Value(indexStats),
-				metric.Labels.values(i.lastClusterInfo, indexName)...,
+				labelValues...,
 			)
 
 		}
@@ -1141,11 +1213,17 @@ func (i *Indices) Collect(ch chan<- prometheus.Metric) {
 				// gaugeVec := prometheus.NewGaugeVec(metric.Opts, metric.Labels)
 				for shardNumber, shards := range indexStats.Shards {
 					for _, shard := range shards {
+						if i.aliases {
+							labelValues = metric.Labels.values(i.lastClusterInfo, indexName, shardNumber, shard.Routing.Node, strconv.FormatBool(shard.Routing.Primary), aliasesString)
+						} else {
+							labelValues = metric.Labels.values(i.lastClusterInfo, indexName, shardNumber, shard.Routing.Node, strconv.FormatBool(shard.Routing.Primary))
+						}
+
 						ch <- prometheus.MustNewConstMetric(
 							metric.Desc,
 							metric.Type,
 							metric.Value(shard),
-							metric.Labels.values(i.lastClusterInfo, indexName, shardNumber, shard.Routing.Node, strconv.FormatBool(shard.Routing.Primary))...,
+							labelValues...,
 						)
 					}
 				}

diff --git a/collector/indices_response.go b/collector/indices_response.go
@@ -18,6 +18,15 @@ type indexStatsResponse struct {
 	Shards  IndexStatsShardsResponse           `json:"_shards"`
 	All     IndexStatsIndexResponse            `json:"_all"`
 	Indices map[string]IndexStatsIndexResponse `json:"indices"`
+	Aliases map[string][]string
+}
+
+// aliasesResponse is a representation of a Elasticsearch Alias Query
+type aliasesResponse map[string]aliasMapping
+
+// aliasMapping is a mapping of index names to a map of associated alias names where the alias names are keys
+type aliasMapping struct {
+	Aliases map[string]map[string]interface{} `json:"aliases"`
 }
 
 // IndexStatsShardsResponse defines index stats shards information structure