logcli: add support for bearer token authentication

cmd/logcli/main.go

@@ -209,6 +209,8 @@ func newQueryClient(app *kingpin.Application) client.Client {
 	app.Flag("cert", "Path to the client certificate. Can also be set using LOKI_CLIENT_CERT_PATH env var.").Default("").Envar("LOKI_CLIENT_CERT_PATH").StringVar(&client.TLSConfig.CertFile)
 	app.Flag("key", "Path to the client certificate key. Can also be set using LOKI_CLIENT_KEY_PATH env var.").Default("").Envar("LOKI_CLIENT_KEY_PATH").StringVar(&client.TLSConfig.KeyFile)
 	app.Flag("org-id", "adds X-Scope-OrgID to API requests for representing tenant ID. Useful for requesting tenant data when bypassing an auth gateway.").Default("").Envar("LOKI_ORG_ID").StringVar(&client.OrgID)
+	app.Flag("bearer-token", "adds the Authorization header to API requests for authentication purposes. Can also be set using LOKI_BEARER_TOKEN env var.").Default("").Envar("LOKI_BEARER_TOKEN").StringVar(&client.BearerToken)
+	app.Flag("bearer-token-file", "adds the Authorization header to API requests for authentication purposes. Can also be set using LOKI_BEARER_TOKEN_FILE env var.").Default("").Envar("LOKI_BEARER_TOKEN_FILE").StringVar(&client.BearerTokenFile)
 
 	return client
 }

docs/sources/getting-started/logcli.md

@@ -42,7 +42,7 @@ $ export LOKI_ADDR=http://localhost:3100
 
 > Note: If you are running Loki behind a proxy server and you have
 > authentication configured, you will also have to pass in LOKI_USERNAME
-> and LOKI_PASSWORD accordingly.
+> and LOKI_PASSWORD, LOKI_BEARER_TOKEN or LOKI_BEARER_TOKEN_FILE accordingly.
 
 ```bash
 $ logcli labels job

pkg/logcli/client/client.go

@@ -48,12 +48,14 @@ type Tripperware func(http.RoundTripper) http.RoundTripper
 
 // Client contains fields necessary to query a Loki instance
 type DefaultClient struct {
-	TLSConfig   config.TLSConfig
-	Username    string
-	Password    string
-	Address     string
-	OrgID       string
-	Tripperware Tripperware
+	TLSConfig       config.TLSConfig
+	Username        string
+	Password        string
+	Address         string
+	OrgID           string
+	Tripperware     Tripperware
+	BearerToken     string
+	BearerTokenFile string
 }
 
 // Query uses the /api/v1/query endpoint to execute an instant query
@@ -181,6 +183,27 @@ func (c *DefaultClient) doRequest(path, query string, quiet bool, out interface{
 		req.Header.Set("X-Scope-OrgID", c.OrgID)
 	}
 
+	if (c.Username != "" || c.Password != "") && (len(c.BearerToken) > 0 || len(c.BearerTokenFile) > 0) {
+		return fmt.Errorf("at most one of HTTP basic auth (username/password), bearer-token & bearer-token-file is allowed to be configured")
+	}
+
+	if len(c.BearerToken) > 0 && len(c.BearerTokenFile) > 0 {
+		return fmt.Errorf("at most one of the options bearer-token & bearer-token-file is allowed to be configured")
+	}
+
+	if c.BearerToken != "" {
+		req.Header.Set("Authorization", "Bearer "+c.BearerToken)
+	}
+
+	if c.BearerTokenFile != "" {
+		b, err := ioutil.ReadFile(c.BearerTokenFile)
+		if err != nil {
+			return fmt.Errorf("unable to read authorization credentials file %s: %s", c.BearerTokenFile, err)
+		}
+		bearerToken := strings.TrimSpace(string(b))
+		req.Header.Set("Authorization", "Bearer "+bearerToken)
+	}
+
 	// Parse the URL to extract the host
 	clientConfig := config.HTTPClientConfig{
 		TLSConfig: c.TLSConfig,
@@ -237,6 +260,27 @@ func (c *DefaultClient) wsConnect(path, query string, quiet bool) (*websocket.Co
 		h.Set("X-Scope-OrgID", c.OrgID)
 	}
 
+	if (c.Username != "" || c.Password != "") && (len(c.BearerToken) > 0 || len(c.BearerTokenFile) > 0) {
+		return nil, fmt.Errorf("at most one of HTTP basic auth (username/password), bearer-token & bearer-token-file is allowed to be configured")
+	}
+
+	if len(c.BearerToken) > 0 && len(c.BearerTokenFile) > 0 {
+		return nil, fmt.Errorf("at most one of the options bearer-token & bearer-token-file is allowed to be configured")
+	}
+
+	if c.BearerToken != "" {
+		h.Set("Authorization", "Bearer "+c.BearerToken)
+	}
+
+	if c.BearerTokenFile != "" {
+		b, err := ioutil.ReadFile(c.BearerTokenFile)
+		if err != nil {
+			return nil, fmt.Errorf("unable to read authorization credentials file %s: %s", c.BearerTokenFile, err)
+		}
+		bearerToken := strings.TrimSpace(string(b))
+		h.Set("Authorization", "Bearer "+bearerToken)
+	}
+
 	ws := websocket.Dialer{
 		TLSClientConfig: tlsConfig,
 	}