try using cluster dns to reach apiserver - for #587

kube/src/config/incluster_config.rs

@@ -4,19 +4,19 @@ use crate::{config::utils, Result};
 
 pub const SERVICE_HOSTENV: &str = "KUBERNETES_SERVICE_HOST";
 pub const SERVICE_PORTENV: &str = "KUBERNETES_SERVICE_PORT";
+pub const SERVICE_DNS: &str = "kubernetes.default.svc";
 const SERVICE_TOKENFILE: &str = "/var/run/secrets/kubernetes.io/serviceaccount/token";
 const SERVICE_CERTFILE: &str = "/var/run/secrets/kubernetes.io/serviceaccount/ca.crt";
 const SERVICE_DEFAULT_NS: &str = "/var/run/secrets/kubernetes.io/serviceaccount/namespace";
 
 /// Returns Kubernetes address from specified environment variables.
 pub fn kube_server() -> Option<String> {
     let host = kube_host()?;
-    let port = kube_port()?;
-    Some(format!("https://{}:{}", host, port))
+    Some(format!("https://{}", host))
 }
 
 fn kube_host() -> Option<String> {
-    env::var(SERVICE_HOSTENV).ok()
+    env::var(SERVICE_DNS).ok()
 }
 
 fn kube_port() -> Option<String> {