add more cluster comparision funcs (#6)

README.md

@@ -12,17 +12,21 @@ USAGE:
    esctl [global options] [command [command options]]
 
 VERSION:
-   v0.0.1
+   v0.0.3
 
 COMMANDS:
-   health     show ES health
-   search, /  search within an index
-   help, h    Shows a list of commands or help for one command
+   search, /       search within an index
+   index, i        manage indicies
+   snapshot, snap  manage snapshots
+   cluster, c      manage cluster[s]
+   help, h         Shows a list of commands or help for one command
 
 GLOBAL OPTIONS:
-   --debug, -d    enable debugging [$ES_DEBUG]
-   --help, -h     show help
-   --version, -v  print the version
+   --debug, -d                  enable debugging [$ES_DEBUG]
+   --config string, -c string   config file [$ES_CONFIG]
+   --cluster string, -C string  cluster alias to work with
+   --help, -h                   show help
+   --version, -v                print the version
 ```
 
 Configure `esctl` with environment variables:
@@ -31,6 +35,23 @@ Configure `esctl` with environment variables:
 - `ES_USER`: username
 - `ES_PASS`: password
 
+Or create a config file such as this:
+
+```yaml
+clusters:
+  default:
+    uri: https://es.foo.bar:9200/
+    user: elastic
+    pass: 123456
+  other:
+    uri: https://myes.foo:9200/
+    user: elastic
+    pass: asdasdasd
+```
+
+If you want to  work on a specific cluster, specify  its name with the
+global `-C` option.
+
 ## Introduction
 
 FIXME

cmd/cluster.go

@@ -0,0 +1,121 @@
+/*
+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),
+			Status(conf),
+			List(conf),
+		},
+	}
+}
+
+func List(conf *cfg.Config) *cli.Command {
+	return &cli.Command{
+		Name:    "list",
+		Usage:   "list configured clusters",
+		Aliases: []string{"ls"},
+
+		Action: func(ctx context.Context, cmd *cli.Command) error {
+			if err := es.List(conf); err != nil {
+				return err
+			}
+
+			return nil
+		},
+	}
+}
+
+func Status(conf *cfg.Config) *cli.Command {
+	return &cli.Command{
+		Name:    "status",
+		Usage:   "show cluster status",
+		Aliases: []string{"s"},
+
+		Flags: []cli.Flag{
+			&cli.BoolFlag{
+				Name:        "all",
+				Usage:       "show status of all clusters",
+				Destination: &conf.All,
+				Aliases:     []string{"a"},
+			},
+		},
+
+		Action: func(ctx context.Context, cmd *cli.Command) error {
+			if err := es.Status(conf); err != nil {
+				return err
+			}
+
+			return nil
+		},
+	}
+}
+
+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/health.go

@@ -1,42 +0,0 @@
-/*
-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"
-
-	"codeberg.org/scip/esctl/pkg/cfg"
-	"codeberg.org/scip/esctl/pkg/es"
-
-	"github.com/urfave/cli/v3"
-)
-
-func Status(conf *cfg.Config) *cli.Command {
-	return &cli.Command{
-		Name:    "status",
-		Usage:   "show ES status",
-		Aliases: []string{"s"},
-		Action: func(ctx context.Context, cmd *cli.Command) error {
-			if err := es.Health(conf); err != nil {
-				return err
-			}
-
-			return nil
-		},
-	}
-}

cmd/root.go

@@ -72,15 +72,20 @@ func Main() int {
 		},
 
 		Commands: []*cli.Command{
-			Status(conf),
 			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)
+				if len(os.Args) > 1 {
+					return nil, err
+				} else {
+					fmt.Println(cmd.UsageText)
+					return nil, nil
+				}
 			}
 
 			log.Init(conf)

go.mod

@@ -40,6 +40,7 @@ require (
 	go.opentelemetry.io/otel v1.35.0 // indirect
 	go.opentelemetry.io/otel/metric v1.35.0 // indirect
 	go.opentelemetry.io/otel/trace v1.35.0 // indirect
+	golang.org/x/exp v0.0.0-20260410095643-746e56fc9e2f // indirect
 	golang.org/x/sys v0.42.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -54,6 +54,8 @@ go.opentelemetry.io/otel/metric v1.35.0 h1:0znxYu2SNyuMSQT4Y9WDWej0VpcsxkuklLa4/
 go.opentelemetry.io/otel/metric v1.35.0/go.mod h1:nKVFgxBZ2fReX6IlyW28MgZojkoAkJGaE8CpgeAU3oE=
 go.opentelemetry.io/otel/trace v1.35.0 h1:dPpEfJu1sDIqruz7BHFG3c7528f6ddfSWfFDVt/xgMs=
 go.opentelemetry.io/otel/trace v1.35.0/go.mod h1:WUk7DtFp1Aw2MkvqGdwiXYDZZNvA/1J8o6xRXLrIkyc=
+golang.org/x/exp v0.0.0-20260410095643-746e56fc9e2f h1:W3F4c+6OLc6H2lb//N1q4WpJkhzJCK5J6kUi1NTVXfM=
+golang.org/x/exp v0.0.0-20260410095643-746e56fc9e2f/go.mod h1:J1xhfL/vlindoeF/aINzNzt2Bket5bjo9sdOYzOsU80=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
 golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

pkg/cfg/config.go

@@ -30,7 +30,7 @@ import (
 )
 
 const (
-	Version string = `v0.0.2`
+	Version string = `v0.0.3`
 )
 
 type Cluster struct {
@@ -44,10 +44,12 @@ 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)
+	All                bool     // cluster status: -a
 }
 
 func NewConfig() *Config {

pkg/es/aux.go

@@ -1,50 +0,0 @@
-/*
-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"
-	"log"
-	"log/slog"
-
-	"codeberg.org/scip/esctl/pkg/cfg"
-)
-
-func Health(conf *cfg.Config) error {
-	res, err := conf.DefaultCluster.ES.Cluster.Health().Do(context.Background())
-	if err != nil {
-		log.Fatalf("Error getting health: %s", err)
-	}
-
-	slog.Debug("ES result", "cluster health", res)
-
-	table := NewTable(2, 5)
-
-	table.headers = []string{bold("SETTING"), bold("STATUS")}
-
-	table.entries = [][]string{
-		{"Cluster Name", Colorize(*&res.Status.Name, res.ClusterName)},
-		{"Active Shards", fmt.Sprintf("%d", res.ActiveShards)},
-		{"Active Primary Shards", fmt.Sprintf("%d", res.ActivePrimaryShards)},
-		{"Indicies", fmt.Sprintf("%d", len(res.Indices))},
-		{"Nodes", fmt.Sprintf("%d", res.NumberOfNodes)},
-	}
-
-	table.PrintMarkdown()
-	return nil
-}

pkg/es/cluster.go

@@ -0,0 +1,473 @@
+/*
+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"
+	"errors"
+	"fmt"
+	"log"
+	"log/slog"
+	"regexp"
+
+	"codeberg.org/scip/esctl/pkg/cfg"
+	"github.com/elastic/go-elasticsearch/v9/typedapi/cluster/health"
+	"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 {
+	if !checkClusterFollower(conf, leader) {
+		return errors.New("leader/follower attribution is invalid, reverse cluster attribution and retry")
+	}
+
+	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("failed to get indicies on %s: %s", alias, err)
+		}
+
+		indices[alias] = make(map[string]*types.IndicesRecord, len(res))
+
+		for _, index := range res {
+			indices[alias][*index.Index] = &index
+		}
+	}
+
+	if !checkClusterStatus(conf, leader, follower) {
+		return errors.New("One of the two clusters is in a failed state")
+	}
+
+	findIlmErrors(conf, leader, follower)
+
+	if findIndicesOnlyOnLeader(conf, indices, leader, follower) &&
+		findOrphanedIndices(conf, indices, leader, follower) &&
+		findFailedFollowerIndices(conf, indices, follower) {
+		fmt.Println("everything's hunky-dory.")
+	}
+
+	return nil
+}
+
+func List(conf *cfg.Config) error {
+	table := NewTable(2, len(conf.Clusters))
+	table.Addheaders("cluster", "uri")
+
+	idx := 0
+	for name, cluster := range conf.Clusters {
+		table.entries[idx] = []string{name, cluster.Uri}
+		idx++
+	}
+
+	table.PrintMarkdown()
+
+	return nil
+}
+
+func Status(conf *cfg.Config) error {
+	clusters := []string{}
+
+	if conf.All {
+		for key, _ := range conf.Clusters {
+			clusters = append(clusters, key)
+		}
+	} else {
+		clusters = []string{"default"}
+	}
+
+	for _, cluster := range clusters {
+		es := conf.DefaultCluster.ES
+		if cluster != "default" {
+			es = conf.Clusters[cluster].ES
+		}
+
+		res, err := es.Cluster.Health().
+			Header("content-type", "application/json").
+			Header("accept", "application/json").
+			Do(context.Background())
+		if err != nil {
+			log.Fatalf("Error getting health: %s", err)
+		}
+
+		slog.Debug("ES result", "cluster health", res)
+
+		table := NewTable(2, 5)
+		table.Addheaders(cluster, "status")
+
+		table.entries = [][]string{
+			{"Cluster Name", Colorize(*&res.Status.Name, res.ClusterName)},
+			{"Active Shards", fmt.Sprintf("%d", res.ActiveShards)},
+			{"Active Primary Shards", fmt.Sprintf("%d", res.ActivePrimaryShards)},
+			{"Indicies", fmt.Sprintf("%d", len(res.Indices))},
+			{"Nodes", fmt.Sprintf("%d", res.NumberOfNodes)},
+		}
+
+		table.PrintMarkdown()
+	}
+
+	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()
+}
+
+func checkClusterFollower(conf *cfg.Config, leader string) bool {
+	stats, err := conf.Clusters[leader].ES.Ccr.Stats().
+		Header("content-type", "application/json").
+		Header("accept", "application/json").
+		Do(context.Background())
+	if err != nil {
+		fmt.Printf("failed to get ccr stats from %s: %s", leader, err)
+		return false
+	}
+
+	if len(stats.AutoFollowStats.AutoFollowedClusters) == 0 {
+		// is not following anyone
+		return true
+	}
+
+	if stats.AutoFollowStats.AutoFollowedClusters[0].ClusterName != "" {
+		fmt.Println("leader/follower attribution is invalid, reverse cluster attribution and retry")
+		return false
+	}
+
+	return true
+}
+
+// checks if both clusters are green
+func checkClusterStatus(conf *cfg.Config, leader, follower string) bool {
+	status := map[string]*health.Response{}
+
+	for _, cluster := range []string{leader, follower} {
+		st, err := conf.Clusters[leader].ES.Cluster.Health().
+			Header("content-type", "application/json").
+			Header("accept", "application/json").
+			Do(context.Background())
+		if err != nil {
+			fmt.Printf("failed to get health from %s: %s", cluster, err)
+			return false
+		}
+
+		status[cluster] = st
+	}
+
+	table := NewTable(3, 5)
+
+	table.Addheaders("setting", "leader:"+leader, "follower:"+follower)
+
+	table.entries = [][]string{
+		{"Cluster Name",
+			Colorize(*&status[leader].Status.Name, status[leader].ClusterName),
+			Colorize(*&status[follower].Status.Name, status[follower].ClusterName),
+		},
+		{"Active Shards",
+			fmt.Sprintf("%d", status[leader].ActiveShards),
+			fmt.Sprintf("%d", status[follower].ActiveShards),
+		},
+		{"Active Primary Shards",
+			fmt.Sprintf("%d", status[leader].ActivePrimaryShards),
+			fmt.Sprintf("%d", status[follower].ActivePrimaryShards),
+		},
+		{"Indicies",
+			fmt.Sprintf("%d", len(status[leader].Indices)),
+			fmt.Sprintf("%d", len(status[follower].Indices)),
+		},
+		{"Nodes",
+			fmt.Sprintf("%d", status[leader].NumberOfNodes),
+			fmt.Sprintf("%d", status[follower].NumberOfNodes),
+		},
+	}
+
+	table.PrintMarkdown()
+
+	if status[leader].Status.Name == "green" && status[follower].Status.Name == "green" {
+		return true
+	}
+
+	return false
+}
+
+// finds indices on both clusters which have ilm errors
+func findIlmErrors(conf *cfg.Config, leader, follower string) bool {
+	failed := map[string]map[string]string{}
+
+	for _, cluster := range []string{leader, follower} {
+		ilm, err := conf.Clusters[cluster].ES.Ilm.ExplainLifecycle("_all").
+			OnlyManaged(true).
+			Header("content-type", "application/json").
+			Header("accept", "application/json").
+			Do(context.Background())
+		if err != nil {
+			fmt.Printf("failed to get ilm status from %s: %s", cluster, err)
+			return false
+		}
+
+		failed[cluster] = map[string]string{}
+
+		for name, ilmstate := range ilm.Indices {
+			count := ilmstate.(*types.LifecycleExplainManaged).FailedStepRetryCount
+
+			if count != nil && *count > 0 {
+				failed[cluster][name] = fmt.Sprintf("%d", *count)
+			}
+		}
+	}
+
+	if len(failed[leader]) == 0 && len(failed[follower]) == 0 {
+		return true
+	}
+
+	for idx, cluster := range []string{leader, follower} {
+		which := "leader"
+		if idx > 0 {
+			which = "follower"
+		}
+
+		if len(failed[cluster]) > 0 {
+			idx := 0
+			table := NewTable(2, len(failed[cluster]))
+			table.Addheaders("ilm errors on "+which, "errors")
+
+			for name, count := range failed[cluster] {
+				table.entries[idx] = []string{name, count}
+				idx++
+			}
+
+			table.Sort()
+			table.PrintMarkdown()
+		}
+	}
+
+	return false
+}
+
+// find unsynchronized indicies only present on leader
+func findIndicesOnlyOnLeader(conf *cfg.Config, indices ClusterIndices, leader, follower string) bool {
+	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
+		}
+	}
+
+	if len(indexOnlyOnLeader) == 0 {
+		return true
+	}
+
+	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()
+
+	return false
+}
+
+// find indices only present on follower
+func findOrphanedIndices(conf *cfg.Config, indices ClusterIndices, leader, follower string) bool {
+	orphaned := map[string]*types.IndicesRecord{}
+
+	for name, index := range indices[follower] {
+		_, leaderHasIt := indices[leader][name]
+		if !leaderHasIt {
+			// fetch index details
+			res, err := conf.Clusters[follower].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
+			}
+
+			orphaned[name] = index
+		}
+	}
+
+	if len(orphaned) == 0 {
+		return true
+	}
+
+	idx := 0
+	table := NewTable(3, len(orphaned))
+	table.Addheaders("orphaned index on follower", "size", "docscount")
+
+	for name, index := range orphaned {
+		name := Colorize("red", name)
+
+		table.entries[idx] = []string{name, *index.DatasetSize, *index.DocsCount}
+		idx++
+	}
+
+	table.Sort()
+	table.PrintMarkdown()
+
+	return false
+}
+
+// find red indices on follower
+func findFailedFollowerIndices(conf *cfg.Config, indices ClusterIndices, follower string) bool {
+	red := map[string]*types.IndicesRecord{}
+
+	for name, index := range indices[follower] {
+		if *index.Health == "red" {
+			red[name] = index
+		}
+	}
+
+	if len(red) == 0 {
+		return true
+	}
+
+	idx := 0
+	table := NewTable(3, len(red))
+	table.Addheaders("red index on follower", "size", "docscount")
+
+	for name, index := range red {
+		name := Colorize("red", name)
+
+		table.entries[idx] = []string{name, *index.DatasetSize, *index.DocsCount}
+		idx++
+	}
+
+	table.Sort()
+	table.PrintMarkdown()
+
+	return false
+}

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)
 	}