add "cluster compare" command and add 1st check (unsync indices) (#2)

cmd/cluster.go

@@ -0,0 +1,78 @@
+/*
+Copyright © 2026 Thomas von Dein
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+package cmd
+
+import (
+	"context"
+	"errors"
+
+	"codeberg.org/scip/esctl/pkg/cfg"
+	"codeberg.org/scip/esctl/pkg/es"
+
+	"github.com/urfave/cli/v3"
+)
+
+func Cluster(conf *cfg.Config) *cli.Command {
+	return &cli.Command{
+		Name:    "cluster",
+		Aliases: []string{"c"},
+		Usage:   "manage cluster[s]",
+
+		Commands: []*cli.Command{
+			Compare(conf),
+		},
+	}
+}
+
+func Compare(conf *cfg.Config) *cli.Command {
+	return &cli.Command{
+		Name:    "compare",
+		Aliases: []string{"c"},
+		Usage:   "compare cluster[s] (yaml config with 2 clusters required)",
+
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name:        "exclude",
+				Usage:       "regexp of indicies to exclude",
+				Destination: &conf.Exclude,
+				Aliases:     []string{"e"},
+			},
+		},
+
+		Action: func(ctx context.Context, cmd *cli.Command) error {
+			leader := cmd.Args().Get(0)
+			follower := cmd.Args().Get(1)
+
+			if leader == "" || follower == "" {
+				return errors.New("no leader and follower aliases specified")
+			}
+
+			_, hasLeader := conf.Clusters[leader]
+			_, hasFollower := conf.Clusters[follower]
+
+			if !hasLeader || !hasFollower {
+				return errors.New("either leader or follower alias not configured")
+			}
+
+			if err := es.ClusterCompare(conf, leader, follower); err != nil {
+				return err
+			}
+
+			return nil
+		},
+	}
+}

cmd/root.go

@@ -76,11 +76,12 @@ func Main() int {
 			Search(conf),
 			Index(conf),
 			Snapshot(conf),
+			Cluster(conf),
 		},
 
 		Before: func(ctx context.Context, cmd *cli.Command) (context.Context, error) {
 			if err := conf.Init(); err != nil {
-				Finish(err)
+				return nil, err
 			}
 
 			log.Init(conf)

pkg/cfg/config.go

@@ -44,10 +44,11 @@ type Config struct {
 	Debug              bool   // -d
 	Clusters           map[string]*Cluster
 	DefaultCluster     *Cluster
-	From, To, MaxItems int
-	Index              string
-	Filter             []string
-	Failed, Partials   bool
+	Index              string   // index: -i
+	Failed, Partials   bool     // index: flags
+	From, To, MaxItems int      // search: flags
+	Filter             []string // search: -F
+	Exclude            string   // cluster compare: -e (regexp)
 }
 
 func NewConfig() *Config {

pkg/es/cluster.go

@@ -0,0 +1,120 @@
+/*
+Copyright © 2026 Thomas von Dein
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+package es
+
+import (
+	"context"
+	"fmt"
+	"regexp"
+
+	"codeberg.org/scip/esctl/pkg/cfg"
+	"github.com/elastic/go-elasticsearch/v9/typedapi/types"
+)
+
+const (
+	DefaultExclude = `(part|monitoring|.internal|metrics-endpoint)`
+)
+
+type ClusterIndices map[string]map[string]*types.IndicesRecord
+
+func ClusterCompare(conf *cfg.Config, leader, follower string) error {
+	indices := ClusterIndices{}
+
+	for _, alias := range []string{leader, follower} {
+		cat := conf.Clusters[alias].ES.Cat.Indices().
+			// we need to add custom request headers, required for older ES instances
+			Header("content-type", "application/json").
+			Header("accept", "application/json")
+
+		res, err := cat.Do(context.Background())
+		if err != nil {
+			return fmt.Errorf("Error getting indicies on %s: %s", alias, err)
+		}
+
+		indices[alias] = make(map[string]*types.IndicesRecord, len(res))
+
+		for _, index := range res {
+			indices[alias][*index.Index] = &index
+		}
+	}
+
+	findIndicesOnlyOnMaster(conf, indices, leader, follower)
+
+	return nil
+}
+
+// look for indicies only on leader
+func findIndicesOnlyOnMaster(conf *cfg.Config, indices ClusterIndices, leader, follower string) {
+	exclude := regexp.MustCompile(DefaultExclude)
+	if conf.Exclude != "" {
+		exclude = regexp.MustCompile(conf.Exclude)
+	}
+
+	indexOnlyOnLeader := map[string]*types.IndicesRecord{}
+	for name, index := range indices[leader] {
+		if exclude.MatchString(name) {
+			continue
+		}
+
+		_, followerHasIt := indices[follower][name]
+		if !followerHasIt {
+			// fetch index details
+			res, err := conf.Clusters[leader].ES.Indices.Get(name).
+				Header("content-type", "application/json").
+				Header("accept", "application/json").
+				Do(context.Background())
+			if err != nil {
+				continue // ignore it then
+			}
+
+			_, defined := res[name]
+			if !defined {
+				// json response map didn't contain the index
+				continue
+			}
+
+			isWritable := false
+			for _, alias := range res[name].Aliases {
+				if *alias.IsWriteIndex {
+					isWritable = true
+					break
+				}
+			}
+
+			if isWritable {
+				// ignore index if associated alias index is writing
+				continue
+			}
+
+			indexOnlyOnLeader[name] = index
+		}
+	}
+
+	idx := 0
+	table := NewTable(3, len(indexOnlyOnLeader))
+	table.Addheaders("index only on leader", "size", "docscount")
+
+	for name, index := range indexOnlyOnLeader {
+		name := Colorize("red", name)
+
+		table.entries[idx] = []string{name, *index.DatasetSize, *index.DocsCount}
+		idx++
+	}
+
+	table.Sort()
+	table.PrintMarkdown()
+}

pkg/es/index.go

@@ -26,7 +26,10 @@ import (
 )
 
 func IndexList(conf *cfg.Config) error {
-	cat := conf.DefaultCluster.ES.Cat.Indices()
+	cat := conf.DefaultCluster.ES.Cat.Indices().
+		// we need to add custom request headers, required for older ES instances
+		Header("content-type", "application/json").
+		Header("accept", "application/json")
 
 	if conf.Failed {
 		cat = cat.Health(healthstatus.Red)
@@ -67,7 +70,11 @@ func IndexList(conf *cfg.Config) error {
 }
 
 func IndexShow(conf *cfg.Config, index string) error {
-	res, err := conf.DefaultCluster.ES.Indices.Get(index).Do(context.Background())
+	res, err := conf.DefaultCluster.ES.Indices.Get(index).
+		// we need to add custom request headers, required for older ES instances
+		Header("content-type", "application/json").
+		Header("accept", "application/json").
+		Do(context.Background())
 	if err != nil {
 		return fmt.Errorf("failed to get index: %s", err)
 	}