Support alternative auth mechanisms (#15)

With this commit we add support for two alternatives to user/password
based authentication:

* API keys
* Service account tokens

Closes #12

README.md

@@ -28,15 +28,34 @@ This [Dockerfile](./Dockerfile) builds a docker image with the k6 binary.
 
 ## Configuration
 
-### Running on Elastic Cloud
+### Running in Production
+
+> [!NOTE]
+> The examples below use Elastic Cloud, which allows to connect via `K6_ELASTICSEARCH_CLOUD_ID`. Alternatively you can also specify the connection URL with `K6_ELASTICSEARCH_URL`.
 
 You can run the new k6 binary against a Cloud cluster with:
 ```shell
 export K6_ELASTICSEARCH_CLOUD_ID=your-cloud-id-here
 export K6_ELASTICSEARCH_USER=elastic
 export K6_ELASTICSEARCH_PASSWORD=your-password-here
 
-./k6 run script.js -o output-elasticsearch
+./k6 run ./examples/script.js -o output-elasticsearch
+```
+
+or alternatively via an [API key](https://www.elastic.co/guide/en/elasticsearch/reference/current/security-api-create-api-key.html) (see also how to [create an API key in Kibana](https://www.elastic.co/guide/en/kibana/current/api-keys.html)):
+```shell
+export K6_ELASTICSEARCH_CLOUD_ID=your-cloud-id-here
+export K6_ELASTICSEARCH_API_KEY=your-base64-encoded-api-key-here
+
+./k6 run ./examples/script.js -o output-elasticsearch
+```
+
+or a [service account token](https://www.elastic.co/guide/en/elasticsearch/reference/current/service-accounts.html#service-accounts-tokens):
+```shell
+export K6_ELASTICSEARCH_CLOUD_ID=your-cloud-id-here
+export K6_ELASTICSEARCH_SERVICE_ACCOUNT_TOKEN=your-service-account-token-here
+
+./k6 run ./examples/script.js -o output-elasticsearch
 ```
 
 ### Running a local cluster

pkg/esoutput/config.go

@@ -44,21 +44,25 @@ type Config struct {
 	CACert             null.String `json:"caCertFile" envconfig:"K6_ELASTICSEARCH_CA_CERT_FILE"`
 	InsecureSkipVerify null.Bool   `json:"insecureSkipVerify" envconfig:"K6_ELASTICSEARCH_INSECURE_SKIP_VERIFY"`
 
-	User     null.String `json:"user" envconfig:"K6_ELASTICSEARCH_USER"`
-	Password null.String `json:"password" envconfig:"K6_ELASTICSEARCH_PASSWORD"`
+	User                null.String `json:"user" envconfig:"K6_ELASTICSEARCH_USER"`
+	Password            null.String `json:"password" envconfig:"K6_ELASTICSEARCH_PASSWORD"`
+	APIKey              null.String `json:"apiKey" envconfig:"K6_ELASTICSEARCH_API_KEY"`
+	ServiceAccountToken null.String `json:"serviceAccountToken" envconfig:"K6_ELASTICSEARCH_SERVICE_ACCOUNT_TOKEN"`
 
 	FlushPeriod types.NullDuration `json:"flushPeriod" envconfig:"K6_ELASTICSEARCH_FLUSH_PERIOD"`
 }
 
 func NewConfig() Config {
 	return Config{
-		Url:                null.StringFrom("http://localhost:9200"),
-		CloudID:            null.NewString("", false),
-		CACert:             null.NewString("", false),
-		InsecureSkipVerify: null.BoolFrom(false),
-		User:               null.NewString("", false),
-		Password:           null.NewString("", false),
-		FlushPeriod:        types.NullDurationFrom(defaultFlushPeriod),
+		Url:                 null.StringFrom("http://localhost:9200"),
+		CloudID:             null.NewString("", false),
+		APIKey:              null.NewString("", false),
+		CACert:              null.NewString("", false),
+		InsecureSkipVerify:  null.BoolFrom(false),
+		User:                null.NewString("", false),
+		Password:            null.NewString("", false),
+		ServiceAccountToken: null.NewString("", false),
+		FlushPeriod:         types.NullDurationFrom(defaultFlushPeriod),
 	}
 }
 
@@ -71,6 +75,9 @@ func (base Config) Apply(applied Config) Config {
 	if applied.CloudID.Valid {
 		base.CloudID = applied.CloudID
 	}
+	if applied.APIKey.Valid {
+		base.APIKey = applied.APIKey
+	}
 
 	if applied.CACert.Valid {
 		base.CACert = applied.CACert
@@ -87,6 +94,10 @@ func (base Config) Apply(applied Config) Config {
 		base.Password = applied.Password
 	}
 
+	if applied.ServiceAccountToken.Valid {
+		base.ServiceAccountToken = applied.ServiceAccountToken
+	}
+
 	if applied.FlushPeriod.Valid {
 		base.FlushPeriod = applied.FlushPeriod
 	}
@@ -125,6 +136,12 @@ func ParseArg(arg string) (Config, error) {
 	if v, ok := params["password"].(string); ok {
 		c.Password = null.StringFrom(v)
 	}
+	if v, ok := params["apiKey"].(string); ok {
+		c.APIKey = null.StringFrom(v)
+	}
+	if v, ok := params["serviceAccountToken"].(string); ok {
+		c.ServiceAccountToken = null.StringFrom(v)
+	}
 
 	if v, ok := params["flushPeriod"].(string); ok {
 		if err := c.FlushPeriod.UnmarshalText([]byte(v)); err != nil {
@@ -165,15 +182,15 @@ func GetConsolidatedConfig(jsonRawConf json.RawMessage, env map[string]string, a
 		}
 	}
 
-	if url, urlDefined := env["K6_ELASTICSEARCH_URL"]; urlDefined {
+	if url, defined := env["K6_ELASTICSEARCH_URL"]; defined {
 		result.Url = null.StringFrom(url)
 	}
 
-	if cloudId, cloudIdDefined := env["K6_ELASTICSEARCH_CLOUD_ID"]; cloudIdDefined {
+	if cloudId, defined := env["K6_ELASTICSEARCH_CLOUD_ID"]; defined {
 		result.CloudID = null.StringFrom(cloudId)
 	}
 
-	if ca, caDefined := env["K6_ELASTICSEARCH_CA_CERT_FILE"]; caDefined {
+	if ca, defined := env["K6_ELASTICSEARCH_CA_CERT_FILE"]; defined {
 		result.CACert = null.StringFrom(ca)
 	}
 
@@ -185,13 +202,19 @@ func GetConsolidatedConfig(jsonRawConf json.RawMessage, env map[string]string, a
 		}
 	}
 
-	if user, userDefined := env["K6_ELASTICSEARCH_USER"]; userDefined {
+	if user, defined := env["K6_ELASTICSEARCH_USER"]; defined {
 		result.User = null.StringFrom(user)
 	}
 
-	if password, passwordDefined := env["K6_ELASTICSEARCH_PASSWORD"]; passwordDefined {
+	if password, defined := env["K6_ELASTICSEARCH_PASSWORD"]; defined {
 		result.Password = null.StringFrom(password)
 	}
+	if apiKey, defined := env["K6_ELASTICSEARCH_API_KEY"]; defined {
+		result.APIKey = null.StringFrom(apiKey)
+	}
+	if serviceAccountToken, defined := env["K6_ELASTICSEARCH_SERVICE_ACCOUNT_TOKEN"]; defined {
+		result.ServiceAccountToken = null.StringFrom(serviceAccountToken)
+	}
 
 	if arg != "" {
 		argConf, err := ParseArg(arg)

pkg/esoutput/esoutput.go

@@ -31,9 +31,9 @@ import (
 	_ "embed"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"net/http"
+	"os"
 	"strings"
 	"time"
 
@@ -80,7 +80,7 @@ func New(params output.Params) (output.Output, error) {
 
 	var esConfig es.Config
 
-	// Cloud id takes precendence over a URL (which is localhost by default)
+	// Cloud id takes precedence over a URL (which is localhost by default)
 	if config.CloudID.Valid {
 		esConfig.CloudID = config.CloudID.String
 	} else if config.Url.Valid {
@@ -92,8 +92,14 @@ func New(params output.Params) (output.Output, error) {
 	if config.Password.Valid {
 		esConfig.Password = config.Password.String
 	}
+	if config.APIKey.Valid {
+		esConfig.APIKey = config.APIKey.String
+	}
+	if config.ServiceAccountToken.Valid {
+		esConfig.ServiceToken = config.ServiceAccountToken.String
+	}
 	if config.CACert.Valid {
-		cert, err := ioutil.ReadFile(config.CACert.String)
+		cert, err := os.ReadFile(config.CACert.String)
 		if err != nil {
 			return nil, err
 		}