add support for config file and multiple clusters config (#1)

cmd/root.go

@@ -37,10 +37,7 @@ func Finish(err error) int {
 }
 
 func Main() int {
-	conf, err := cfg.Init()
-	if err != nil {
-		return Finish(err)
-	}
+	conf := cfg.NewConfig()
 
 	cmd := &cli.Command{
 		Name:                  "esctl",
@@ -57,6 +54,21 @@ func Main() int {
 				Sources:     cli.EnvVars("ES_DEBUG"),
 				Destination: &conf.Debug,
 			},
+			&cli.StringFlag{
+				Name:        "config",
+				Aliases:     []string{"c"},
+				Value:       "",
+				Usage:       "config file",
+				Sources:     cli.EnvVars("ES_CONFIG"),
+				Destination: &conf.ConfigFile,
+			},
+			&cli.StringFlag{
+				Name:        "cluster",
+				Aliases:     []string{"C"},
+				Value:       "",
+				Usage:       "cluster alias to work with",
+				Destination: &conf.CurrentCluster,
+			},
 		},
 
 		Commands: []*cli.Command{
@@ -67,7 +79,12 @@ func Main() int {
 		},
 
 		Before: func(ctx context.Context, cmd *cli.Command) (context.Context, error) {
+			if err := conf.Init(); err != nil {
+				Finish(err)
+			}
+
 			log.Init(conf)
+
 			return nil, nil
 		},
 	}

pkg/cfg/config.go

@@ -19,56 +19,147 @@ package cfg
 import (
 	"crypto/tls"
 	"errors"
+	"fmt"
 	"net/http"
 	"os"
 
+	"github.com/alecthomas/repr"
 	"github.com/elastic/elastic-transport-go/v8/elastictransport"
 	"github.com/elastic/go-elasticsearch/v9"
+	"gopkg.in/yaml.v3"
 )
 
 const (
-	Version string = `v0.0.1`
+	Version string = `v0.0.2`
 )
 
+type Cluster struct {
+	Uri, User, Pass string
+	ES              *elasticsearch.TypedClient
+}
+
 type Config struct {
-	Uri, User, Pass    string
-	ES                 *elasticsearch.TypedClient
-	Debug              bool
+	ConfigFile         string // -c
+	CurrentCluster     string // -C
+	Debug              bool   // -d
+	Clusters           map[string]*Cluster
+	DefaultCluster     *Cluster
 	From, To, MaxItems int
 	Index              string
 	Filter             []string
 	Failed, Partials   bool
 }
 
-func Init() (*Config, error) {
-	cfg := Config{
+func NewConfig() *Config {
+	return &Config{Clusters: map[string]*Cluster{}}
+}
+
+func (conf *Config) Init() error {
+	if conf.ConfigFile != "" {
+		if err := conf.LoadConfig(); err != nil {
+			return err
+		}
+	} else {
+		if err := conf.LoadEnv(); err != nil {
+			return err
+		}
+	}
+
+	if conf.CurrentCluster != "" {
+		current, exists := conf.Clusters[conf.CurrentCluster]
+		if !exists {
+			return fmt.Errorf("no cluster with alias %s configured", conf.CurrentCluster)
+		} else {
+			conf.DefaultCluster = current
+		}
+	}
+
+	if conf.Debug {
+		repr.Println(conf)
+	}
+
+	conf.SetupES()
+
+	return nil
+}
+
+func (conf *Config) LoadEnv() error {
+	cluster := Cluster{
 		Uri:  os.Getenv("ES_URI"),
 		User: os.Getenv("ES_USER"),
 		Pass: os.Getenv("ES_PASS"),
 	}
 
 	switch {
-	case cfg.Uri == "":
-		return nil, errors.New("ES_URI unset")
-	case cfg.User == "":
-		return nil, errors.New("ES_USER unset")
-	case cfg.Pass == "":
-		return nil, errors.New("ES_PASS unset")
+	case cluster.Uri == "":
+		return errors.New("ES_URI unset")
+	case cluster.User == "":
+		return errors.New("ES_USER unset")
+	case cluster.Pass == "":
+		return errors.New("ES_PASS unset")
 	}
 
-	es, _ := elasticsearch.NewTyped(
-		elasticsearch.WithAddresses(cfg.Uri),
-		elasticsearch.WithBasicAuth(cfg.User, cfg.Pass),
-		elasticsearch.WithTransportOptions(
-			elastictransport.WithTransport(
-				&http.Transport{
-					TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
-				},
-			),
-		),
-	)
+	conf.Clusters["default"] = &cluster
+	conf.DefaultCluster = &cluster
 
-	cfg.ES = es
-
-	return &cfg, nil
+	return nil
+}
+
+func (conf *Config) LoadConfig() error {
+	if conf.ConfigFile == "" {
+		return nil
+	}
+
+	data, err := os.ReadFile(conf.ConfigFile)
+	if err != nil {
+		return fmt.Errorf("failed to read config file: %w", err)
+	}
+
+	newconf := &Config{}
+
+	err = yaml.Unmarshal(data, newconf)
+	if err != nil {
+		return fmt.Errorf("failed to unmarshal config file: %w", err)
+	}
+
+	if len(newconf.Clusters) > 0 {
+		conf.Clusters = newconf.Clusters
+
+		_, exists := conf.Clusters["default"]
+		if !exists {
+			// no "default", just use the first we stumble upon
+			for _, cluster := range conf.Clusters {
+				conf.DefaultCluster = cluster
+				break
+			}
+		} else {
+			conf.DefaultCluster = newconf.Clusters["default"]
+		}
+	}
+
+	return nil
+}
+
+func (conf *Config) SetupES() error {
+	for _, cluster := range conf.Clusters {
+		es, err := elasticsearch.NewTyped(
+			elasticsearch.WithAddresses(cluster.Uri),
+			elasticsearch.WithBasicAuth(cluster.User, cluster.Pass),
+			elasticsearch.WithTransportOptions(
+				elastictransport.WithTransport(
+					&http.Transport{
+						TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
+					},
+				),
+			),
+		)
+
+		if err != nil {
+			return fmt.Errorf("failed to setup elasticsearch connection: %w", err)
+		}
+
+		cluster.ES = es
+	}
+
+	return nil
 }

pkg/es/aux.go

@@ -26,7 +26,7 @@ import (
 )
 
 func Health(conf *cfg.Config) error {
-	res, err := conf.ES.Cluster.Health().Do(context.Background())
+	res, err := conf.DefaultCluster.ES.Cluster.Health().Do(context.Background())
 	if err != nil {
 		log.Fatalf("Error getting health: %s", err)
 	}

pkg/es/index.go

@@ -26,7 +26,7 @@ import (
 )
 
 func IndexList(conf *cfg.Config) error {
-	cat := conf.ES.Cat.Indices()
+	cat := conf.DefaultCluster.ES.Cat.Indices()
 
 	if conf.Failed {
 		cat = cat.Health(healthstatus.Red)
@@ -67,7 +67,7 @@ func IndexList(conf *cfg.Config) error {
 }
 
 func IndexShow(conf *cfg.Config, index string) error {
-	res, err := conf.ES.Indices.Get(index).Do(context.Background())
+	res, err := conf.DefaultCluster.ES.Indices.Get(index).Do(context.Background())
 	if err != nil {
 		return fmt.Errorf("failed to get index: %s", err)
 	}

pkg/es/search.go

@@ -53,7 +53,7 @@ func Search(conf *cfg.Config, q string) error {
 		query.Filter(filters...)
 	}
 
-	res, err := conf.ES.Search().
+	res, err := conf.DefaultCluster.ES.Search().
 		Index(conf.Index).
 		Request(&search.Request{
 			Query: query.QueryCaster(),

pkg/es/snapshot.go

@@ -42,7 +42,7 @@ type Snapshot struct {
 
 func SnapshotList(conf *cfg.Config) error {
 	// get partial indicies
-	ires, err := conf.ES.Cat.Indices().Do(context.Background())
+	ires, err := conf.DefaultCluster.ES.Cat.Indices().Do(context.Background())
 	if err != nil {
 		return fmt.Errorf("Error getting indicies: %s", err)
 	}
@@ -55,7 +55,7 @@ func SnapshotList(conf *cfg.Config) error {
 	}
 
 	// get snapshots
-	sres, err := conf.ES.Cat.Snapshots().Do(context.Background())
+	sres, err := conf.DefaultCluster.ES.Cat.Snapshots().Do(context.Background())
 	if err != nil {
 		return fmt.Errorf("Error getting snapshots: %s", err)
 	}
@@ -103,7 +103,7 @@ func SnapshotList(conf *cfg.Config) error {
 }
 
 func SnapshotShow(conf *cfg.Config, snapshot string) error {
-	res, err := conf.ES.Snapshot.Get("*", snapshot).Do(context.Background())
+	res, err := conf.DefaultCluster.ES.Snapshot.Get("*", snapshot).Do(context.Background())
 	if err != nil {
 		return fmt.Errorf("failed to get snapshot: %s", err)
 	}

sample-2-clusters.yaml

@@ -0,0 +1,9 @@
+clusters:
+  default:
+    uri: https://es.foo.bar:9200/
+    user: elastic
+    pass: 123456
+  other:
+    uri: https://myes.foo:9200/
+    user: elastic
+    pass: asdasdasd