diff --git a/README.md b/README.md
index 81e217b..8dea942 100644
--- a/README.md
+++ b/README.md
@@ -7,20 +7,19 @@ usage: clickhouse-exporter [<flags>]
 
 Flags:
   -h, --help                   Show context-sensitive help (also try --help-long and --help-man).
-      --chi-name="localhost"
-                               Clickhouse cluster name.
-      --namespace="default"    The namespace label for metrics.
+      --chi-name="MacBook-Pro.local"
+                               Clickhouse cluster name or $HOSTNAME.
+      --namespace="default"    The namespace label for metrics or $NAMESPACE.
       --metrics-endpoint=":8888"
                                The Prometheus exporter endpoint.
       --chi-list-endpoint=":8888"
                                The CHI list endpoint.
-      --scheme=http            Clickhouse HTTP scheme.
-      --username="default"     Clickhouse username.
-      --password=""            Clickhouse user password.
-      --port=8123              Clickhouse HTTP port number.
+      --scheme=http            Clickhouse HTTP scheme or $CH_SCHEME
+      --username="default"     Clickhouse username or $CH_USERNAME.
+      --password=""            Clickhouse user password or $CH_PASSWORD.
+      --port=8123              Clickhouse HTTP port number or $CH_PORT.
       --address=127.0.0.1 ...  A list of Clickhouse hosts
-      --log-level=info         Only log messages with the given severity or above. Valid levels: [debug, info, warn,
-                               error, fatal]
+      --log-level=info         Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal]
       --log-format=json        Set the log format. Valid formats: [json, text]
       --version                Show application version.
 ```
diff --git a/main.go b/main.go
index d08608c..d7d9aba 100644
--- a/main.go
+++ b/main.go
@@ -48,21 +48,21 @@ var (
 
 func init() {
 	host, _ := os.Hostname()
-	kingpin.Flag("chi-name", "Clickhouse cluster name.").
-		Default(host).StringVar(&chiName)
-	kingpin.Flag("namespace", "The namespace label for metrics.").
+	kingpin.Flag("chi-name", "Clickhouse cluster name or $HOSTNAME.").
+		Default(host).Envar("HOSTNAME").StringVar(&chiName)
+	kingpin.Flag("namespace", "The namespace label for metrics or $NAMESPACE.").
 		Default(defaultNamespace).Envar("NAMESPACE").StringVar(&namespace)
 	kingpin.Flag("metrics-endpoint", "The Prometheus exporter endpoint.").
 		Default(defaultMetricsEndpoint).StringVar(&metricsEP)
 	kingpin.Flag("chi-list-endpoint", "The CHI list endpoint.").
 		Default(defaultChiListEP).StringVar(&chiListEP)
-	kingpin.Flag("scheme", "Clickhouse HTTP scheme.").
+	kingpin.Flag("scheme", "Clickhouse HTTP scheme or $CH_SCHEME").
 		Default(defaultChScheme).Envar("CH_SCHEME").EnumVar(&scheme, "http", "https")
-	kingpin.Flag("username", "Clickhouse username.").
+	kingpin.Flag("username", "Clickhouse username or $CH_USERNAME.").
 		Default(defaultChUser).Envar("CH_USERNAME").StringVar(&username)
-	kingpin.Flag("password", "Clickhouse user password.").
+	kingpin.Flag("password", "Clickhouse user password or $CH_PASSWORD.").
 		Default(defaultChPass).Envar("CH_PASSWORD").StringVar(&password)
-	kingpin.Flag("port", "Clickhouse HTTP port number.").
+	kingpin.Flag("port", "Clickhouse HTTP port number or $CH_PORT.").
 		Default(defaultChPort).Envar("CH_PORT").IntVar(&port)
 	kingpin.Flag("address", "A list of Clickhouse hosts").
 		Default(defaultChHost).StringsVar(&hostnames)