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fix(k8s): support merge/json patch types in k8s_patch_resource (CRDs reject strategic merge) #62

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fix(k8s): support merge/json patch types in k8s_patch_resource (CRDs reject strategic merge) #62

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14 changes: 12 additions & 2 deletions pkg/k8s/k8s.go
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Original file line number Diff line number Diff line change
Expand Up @@ -132,11 +132,20 @@ func (k *K8sTool) handlePatchResource(ctx context.Context, request mcp.CallToolR
resourceName := mcp.ParseString(request, "resource_name", "")
patch := mcp.ParseString(request, "patch", "")
namespace := mcp.ParseString(request, "namespace", "default")
patchType := mcp.ParseString(request, "patch_type", "strategic")

if resourceType == "" || resourceName == "" || patch == "" {
return mcp.NewToolResultError("resource_type, resource_name, and patch parameters are required"), nil
}

// Validate patch type. "strategic" is only implemented for built-in Kubernetes
// types; CustomResources (CRDs) reject it and require "merge" or "json".
switch patchType {
case "strategic", "merge", "json":
default:
return mcp.NewToolResultError(fmt.Sprintf("Invalid patch_type %q: must be one of strategic, merge, json", patchType)), nil
}

// Validate resource name for security
if err := security.ValidateK8sResourceName(resourceName); err != nil {
return mcp.NewToolResultError(fmt.Sprintf("Invalid resource name: %v", err)), nil
Expand All @@ -152,7 +161,7 @@ func (k *K8sTool) handlePatchResource(ctx context.Context, request mcp.CallToolR
return mcp.NewToolResultError(fmt.Sprintf("Invalid patch content: %v", err)), nil
}

args := []string{"patch", resourceType, resourceName, "-p", patch, "-n", namespace}
args := []string{"patch", resourceType, resourceName, "--type=" + patchType, "-p", patch, "-n", namespace}

return k.runKubectlCommandWithCacheInvalidation(ctx, request.Header, args...)
}
Expand Down Expand Up @@ -717,10 +726,11 @@ func RegisterTools(s *server.MCPServer, llm llms.Model, kubeconfig string, readO
), telemetry.AdaptToolHandler(telemetry.WithTracing("k8s_scale", k8sTool.handleScaleDeployment)))

s.AddTool(mcp.NewTool("k8s_patch_resource",
mcp.WithDescription("Patch a Kubernetes resource using strategic merge patch"),
mcp.WithDescription("Patch a Kubernetes resource. Defaults to a strategic merge patch, which is only supported for built-in types; set patch_type to \"merge\" (or \"json\") to patch a CustomResource/CRD."),
mcp.WithString("resource_type", mcp.Description("Type of resource (deployment, service, etc.)"), mcp.Required()),
mcp.WithString("resource_name", mcp.Description("Name of the resource"), mcp.Required()),
mcp.WithString("patch", mcp.Description("JSON patch to apply"), mcp.Required()),
mcp.WithString("patch_type", mcp.Description("Patch strategy: \"strategic\" (default; built-in Kubernetes types only), \"merge\" (RFC 7386 JSON merge patch; required for CustomResources/CRDs), or \"json\" (RFC 6902 JSON patch).")),
mcp.WithString("namespace", mcp.Description("Namespace of the resource (default: default)")),
), telemetry.AdaptToolHandler(telemetry.WithTracing("k8s_patch_resource", k8sTool.handlePatchResource)))

Expand Down
53 changes: 51 additions & 2 deletions pkg/k8s/k8s_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -242,7 +242,7 @@ func TestHandlePatchResource(t *testing.T) {
t.Run("valid parameters", func(t *testing.T) {
mock := cmd.NewMockShellExecutor()
expectedOutput := `deployment.apps/test-deployment patched`
mock.AddCommandString("kubectl", []string{"patch", "deployment", "test-deployment", "-p", `{"spec":{"replicas":5}}`, "-n", "default"}, expectedOutput, nil)
mock.AddCommandString("kubectl", []string{"patch", "deployment", "test-deployment", "--type=strategic", "-p", `{"spec":{"replicas":5}}`, "-n", "default"}, expectedOutput, nil)
ctx := cmd.WithShellExecutor(ctx, mock)

k8sTool := newTestK8sTool()
Expand All @@ -262,6 +262,55 @@ func TestHandlePatchResource(t *testing.T) {
resultText := getResultText(result)
assert.Contains(t, resultText, "patched")
})

t.Run("merge patch type for CustomResource", func(t *testing.T) {
mock := cmd.NewMockShellExecutor()
expectedOutput := `installer.composition.krateo.io/installer patched`
mock.AddCommandString("kubectl", []string{"patch", "installers.composition.krateo.io", "installer", "--type=merge", "-p", `{"spec":{"features":{"composableportal":true}}}`, "-n", "krateo-system"}, expectedOutput, nil)
ctx := cmd.WithShellExecutor(ctx, mock)

k8sTool := newTestK8sTool()

req := mcp.CallToolRequest{}
req.Params.Arguments = map[string]interface{}{
"resource_type": "installers.composition.krateo.io",
"resource_name": "installer",
"patch": `{"spec":{"features":{"composableportal":true}}}`,
"patch_type": "merge",
"namespace": "krateo-system",
}

result, err := k8sTool.handlePatchResource(ctx, req)
assert.NoError(t, err)
assert.NotNil(t, result)
assert.False(t, result.IsError)

resultText := getResultText(result)
assert.Contains(t, resultText, "patched")
})

t.Run("invalid patch type", func(t *testing.T) {
mock := cmd.NewMockShellExecutor()
ctx := cmd.WithShellExecutor(context.Background(), mock)

k8sTool := newTestK8sTool()

req := mcp.CallToolRequest{}
req.Params.Arguments = map[string]interface{}{
"resource_type": "deployment",
"resource_name": "test-deployment",
"patch": `{"spec":{"replicas":5}}`,
"patch_type": "bogus",
}

result, err := k8sTool.handlePatchResource(ctx, req)
assert.NoError(t, err)
assert.NotNil(t, result)
assert.True(t, result.IsError)

// No command should run for an invalid patch type.
assert.Len(t, mock.GetCallLog(), 0)
})
}

func TestHandlePatchStatus(t *testing.T) {
Expand Down Expand Up @@ -1232,7 +1281,7 @@ log line 2`
t.Run("patch resource with bearer token", func(t *testing.T) {
mock := cmd.NewMockShellExecutor()
expectedOutput := `deployment.apps/test-deployment patched`
mock.AddCommandString("kubectl", []string{"patch", "deployment", "test-deployment", "-p", `{"spec":{"replicas":5}}`, "-n", "default", "--token", "patch-token"}, expectedOutput, nil)
mock.AddCommandString("kubectl", []string{"patch", "deployment", "test-deployment", "--type=strategic", "-p", `{"spec":{"replicas":5}}`, "-n", "default", "--token", "patch-token"}, expectedOutput, nil)
ctx := cmd.WithShellExecutor(ctx, mock)

k8sTool := newTestK8sToolWithPassthrough(true)
Expand Down