feat(kubernetes): pods_log for explicit or nil namespace

Author: manusa

pkg/kubernetes/kubernetes.go

@@ -63,3 +63,12 @@ func resolveClientConfig() (*rest.Config, error) {
 	}
 	return resolveConfig().ClientConfig()
 }
+
+func namespaceOrDefault(namespace string) string {
+	if namespace == "" {
+		if ns, _, nsErr := resolveConfig().Namespace(); nsErr == nil {
+			namespace = ns
+		}
+	}
+	return namespace
+}

pkg/kubernetes/pods.go

@@ -2,7 +2,9 @@ package kubernetes
 
 import (
 	"context"
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/kubernetes"
 )
 
 func (k *Kubernetes) PodsListInAllNamespaces(ctx context.Context) (string, error) {
@@ -18,12 +20,27 @@ func (k *Kubernetes) PodsListInNamespace(ctx context.Context, namespace string)
 }
 
 func (k *Kubernetes) PodsGet(ctx context.Context, namespace, name string) (string, error) {
-	if namespace == "" {
-		if ns, _, nsErr := resolveConfig().Namespace(); nsErr == nil {
-			namespace = ns
-		}
-	}
 	return k.ResourcesGet(ctx, &schema.GroupVersionKind{
 		Group: "", Version: "v1", Kind: "Pod",
-	}, namespace, name)
+	}, namespaceOrDefault(namespace), name)
+}
+
+func (k *Kubernetes) PodsLog(ctx context.Context, namespace, name string) (string, error) {
+	cs, err := kubernetes.NewForConfig(k.cfg)
+	if err != nil {
+		return "", err
+	}
+	tailLines := int64(256)
+	req := cs.CoreV1().Pods(namespaceOrDefault(namespace)).GetLogs(name, &v1.PodLogOptions{
+		TailLines: &tailLines,
+	})
+	res := req.Do(ctx)
+	if res.Error() != nil {
+		return "", res.Error()
+	}
+	rawData, err := res.Raw()
+	if err != nil {
+		return "", err
+	}
+	return string(rawData), nil
 }

pkg/mcp/pods.go

@@ -23,7 +23,7 @@ func (s *Sever) initPods() {
 	), podsListInNamespace)
 	s.server.AddTool(mcp.NewTool(
 		"pods_get",
-		mcp.WithDescription("Get a Kubernetes Pod in the current namespace with the provided name"),
+		mcp.WithDescription("Get a Kubernetes Pod in the current or provided namespace with the provided name"),
 		mcp.WithString("namespace",
 			mcp.Description("Namespace to get the Pod from"),
 		),
@@ -32,6 +32,17 @@ func (s *Sever) initPods() {
 			mcp.Required(),
 		),
 	), podsGet)
+	s.server.AddTool(mcp.NewTool(
+		"pods_log",
+		mcp.WithDescription("Get the logs of a Kubernetes Pod in the current or provided namespace with the provided name"),
+		mcp.WithString("namespace",
+			mcp.Description("Namespace to get the Pod logs from"),
+		),
+		mcp.WithString("name",
+			mcp.Description("Name of the Pod"),
+			mcp.Required(),
+		),
+	), podsLog)
 }
 
 func podsListInAllNamespaces(ctx context.Context, _ mcp.CallToolRequest) (*mcp.CallToolResult, error) {
@@ -81,3 +92,23 @@ func podsGet(ctx context.Context, ctr mcp.CallToolRequest) (*mcp.CallToolResult,
 	}
 	return NewTextResult(ret, err), nil
 }
+
+func podsLog(ctx context.Context, ctr mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+	k, err := kubernetes.NewKubernetes()
+	if err != nil {
+		return NewTextResult("", fmt.Errorf("failed to get pod log: %v", err)), nil
+	}
+	ns := ctr.Params.Arguments["namespace"]
+	if ns == nil {
+		ns = ""
+	}
+	name := ctr.Params.Arguments["name"]
+	if name == nil {
+		return NewTextResult("", errors.New("failed to get pod log, missing argument name")), nil
+	}
+	ret, err := k.PodsLog(ctx, ns.(string), name.(string))
+	if err != nil {
+		return NewTextResult("", fmt.Errorf("failed to get pod %s log in namespace %s: %v", name, ns, err)), nil
+	}
+	return NewTextResult(ret, err), nil
+}

pkg/mcp/pods_test.go

@@ -198,3 +198,47 @@ func TestPodsGet(t *testing.T) {
 		})
 	})
 }
+
+func TestPodsLog(t *testing.T) {
+	testCase(t, func(c *mcpContext) {
+		c.withEnvTest()
+		t.Run("pods_log with nil name returns error", func(t *testing.T) {
+			toolResult, _ := c.callTool("pods_log", map[string]interface{}{})
+			if toolResult.IsError != true {
+				t.Fatalf("call tool should fail")
+				return
+			}
+			if toolResult.Content[0].(map[string]interface{})["text"].(string) != "failed to get pod log, missing argument name" {
+				t.Fatalf("invalid error message, got %v", toolResult.Content[0].(map[string]interface{})["text"].(string))
+				return
+			}
+		})
+		podsLogNilNamespace, err := c.callTool("pods_log", map[string]interface{}{
+			"name": "a-pod-in-default",
+		})
+		t.Run("pods_log with name and nil namespace returns pod log", func(t *testing.T) {
+			if err != nil {
+				t.Fatalf("call tool failed %v", err)
+				return
+			}
+			if podsLogNilNamespace.IsError {
+				t.Fatalf("call tool failed")
+				return
+			}
+		})
+		podsLogInNamespace, err := c.callTool("pods_log", map[string]interface{}{
+			"namespace": "ns-1",
+			"name":      "a-pod-in-ns-1",
+		})
+		t.Run("pods_log with name and namespace returns pod log", func(t *testing.T) {
+			if err != nil {
+				t.Fatalf("call tool failed %v", err)
+				return
+			}
+			if podsLogInNamespace.IsError {
+				t.Fatalf("call tool failed")
+				return
+			}
+		})
+	})
+}