feat(plugin): add support to fetch ns from kubeconfig context

If '--namespace-from-context' flag is set then we fetch ns from the kubeconfig
context. Its hidden to users now. Incase user has not given -n flag and
--namespace-from-context we default to "mayastor". If they have used
--namespace-from-context flag then we get ns from kubeconfig. If
kubeconfig path is specified then we use client of that kubeconfig or
else we get default kubeconfig client.

Signed-off-by: Abhilash Shetty <[email protected]>

k8s/plugin/Cargo.toml

@@ -24,6 +24,7 @@ rest-plugin = { path = "../../dependencies/control-plane/control-plane/plugin",
 console-logger = { path = "../../console-logger" }
 supportability = { path = "../supportability" }
 upgrade = { path = "../upgrade" }
+kube = { version = "0.94.2", features = ["derive", "runtime"] }
 kube-proxy = { path = "../../dependencies/control-plane/k8s/proxy" }
 kube-forward = { path = "../../dependencies/control-plane/k8s/forward" }
 tokio = { version = "1.41.0" }

k8s/plugin/src/main.rs

@@ -1,11 +1,11 @@
 use clap::Parser;
 use plugin::ExecuteOperation;
 use resources::{init_rest, Error, Operations};
+pub mod resources;
 
+use kube::Client;
 use std::{env, ops::Deref};
 
-pub mod resources;
-
 #[derive(Parser, Debug)]
 #[clap(name = utils::package_description!(), version = utils::version_info_str!())]
 #[group(skip)]
@@ -15,17 +15,36 @@ struct CliArgs {
     operations: Operations,
 
     /// Kubernetes namespace of mayastor service
-    #[clap(global = true, long, short = 'n', default_value = "mayastor")]
-    namespace: String,
+    #[clap(global = true, long, short = 'n')]
+    namespace: Option<String>,
 
     #[clap(flatten)]
     args: resources::CliArgs,
+
+    /// Use namespace from the current `kubeconfig` context.
+    #[clap(global = true, long, hide = true, default_value = "false")]
+    namespace_from_context: bool,
 }
 
 impl CliArgs {
-    fn args() -> Self {
+    async fn args() -> Self {
         let mut args = CliArgs::parse();
-        args.args.namespace = args.namespace.clone();
+        args.args.namespace = if let Some(namespace) = &args.namespace {
+            namespace.to_string()
+        } else if args.namespace_from_context {
+            let client = if let Some(path) = &args.args.kube_config_path {
+                kube_proxy::client_from_kubeconfig(Some(path.clone()))
+                    .await
+                    .expect("Couldnt create client from supplied kubeconfig")
+            } else {
+                Client::try_default()
+                    .await
+                    .expect("Couldnt create client from default kubeconfig")
+            };
+            client.default_namespace().to_string()
+        } else {
+            "mayastor".to_string()
+        };
         args
     }
 }
@@ -40,7 +59,7 @@ impl Deref for CliArgs {
 
 #[tokio::main]
 async fn main() {
-    let cli_args = CliArgs::args();
+    let cli_args = CliArgs::args().await;
     let _tracer_flusher = cli_args.init_tracing();
 
     if let Err(error) = cli_args.execute().await {