feat(kubernetes): add support for previousPod container logs (#256)

Add 'previous' parameter to pods_log tool to retrieve logs from terminated containers, equivalent to kubectl logs --previous functionality.
This enables debugging of containers that have restarted due to crashes or updates.

Signed-off-by: Samuel Masuy <[email protected]>
Co-authored-by: opencode <[email protected]>

Author: samuelmasuy

README.md

@@ -317,6 +317,8 @@ Get the logs of a Kubernetes Pod in the current or provided namespace with the p
   - Namespace to get the Pod logs from
 - `container` (`string`, optional)
   - Name of the Pod container to get logs from
+- `previous` (`boolean`, optional)
+  - Return previous terminated container logs
 
 ### `pods_run`
 

pkg/kubernetes/pods.go

@@ -92,7 +92,7 @@ func (k *Kubernetes) PodsDelete(ctx context.Context, namespace, name string) (st
 		k.ResourcesDelete(ctx, &schema.GroupVersionKind{Group: "", Version: "v1", Kind: "Pod"}, namespace, name)
 }
 
-func (k *Kubernetes) PodsLog(ctx context.Context, namespace, name, container string) (string, error) {
+func (k *Kubernetes) PodsLog(ctx context.Context, namespace, name, container string, previous bool) (string, error) {
 	tailLines := int64(256)
 	pods, err := k.manager.accessControlClientSet.Pods(k.NamespaceOrDefault(namespace))
 	if err != nil {
@@ -101,6 +101,7 @@ func (k *Kubernetes) PodsLog(ctx context.Context, namespace, name, container str
 	req := pods.GetLogs(name, &v1.PodLogOptions{
 		TailLines: &tailLines,
 		Container: container,
+		Previous:  previous,
 	})
 	res := req.Do(ctx)
 	if res.Error() != nil {

pkg/mcp/pods.go

@@ -99,6 +99,7 @@ func (s *Server) initPods() []server.ServerTool {
 			mcp.WithString("namespace", mcp.Description("Namespace to get the Pod logs from")),
 			mcp.WithString("name", mcp.Description("Name of the Pod to get the logs from"), mcp.Required()),
 			mcp.WithString("container", mcp.Description("Name of the Pod container to get the logs from (Optional)")),
+			mcp.WithBoolean("previous", mcp.Description("Return previous terminated container logs (Optional)")),
 			// Tool annotations
 			mcp.WithTitleAnnotation("Pods: Log"),
 			mcp.WithReadOnlyHintAnnotation(true),
@@ -284,11 +285,16 @@ func (s *Server) podsLog(ctx context.Context, ctr mcp.CallToolRequest) (*mcp.Cal
 	if container == nil {
 		container = ""
 	}
+	previous := ctr.GetArguments()["previous"]
+	var previousBool bool
+	if previous != nil {
+		previousBool = previous.(bool)
+	}
 	derived, err := s.k.Derived(ctx)
 	if err != nil {
 		return nil, err
 	}
-	ret, err := derived.PodsLog(ctx, ns.(string), name.(string), container.(string))
+	ret, err := derived.PodsLog(ctx, ns.(string), name.(string), container.(string), previousBool)
 	if err != nil {
 		return NewTextResult("", fmt.Errorf("failed to get pod %s log in namespace %s: %v", name, ns, err)), nil
 	} else if ret == "" {

pkg/mcp/pods_test.go

@@ -719,6 +719,36 @@ func TestPodsLog(t *testing.T) {
 				return
 			}
 		})
+		podsPreviousLogInNamespace, err := c.callTool("pods_log", map[string]interface{}{
+			"namespace": "ns-1",
+			"name":      "a-pod-in-ns-1",
+			"previous":  true,
+		})
+		t.Run("pods_log with previous=true returns previous pod log", func(t *testing.T) {
+			if err != nil {
+				t.Fatalf("call tool failed %v", err)
+				return
+			}
+			if podsPreviousLogInNamespace.IsError {
+				t.Fatalf("call tool failed")
+				return
+			}
+		})
+		podsPreviousLogFalse, err := c.callTool("pods_log", map[string]interface{}{
+			"namespace": "ns-1",
+			"name":      "a-pod-in-ns-1",
+			"previous":  false,
+		})
+		t.Run("pods_log with previous=false returns current pod log", func(t *testing.T) {
+			if err != nil {
+				t.Fatalf("call tool failed %v", err)
+				return
+			}
+			if podsPreviousLogFalse.IsError {
+				t.Fatalf("call tool failed")
+				return
+			}
+		})
 	})
 }