Support port-forwarding for appropriate resources (#237)

Contributes to #234.

docs/index.md

@@ -16,9 +16,9 @@ With Kele, you can:
 
 - Manage [contexts], e.g. [switching, renaming, changing the default
   namespace](./how-tos/usage.md#contexts);
-- [Fetch and display the manifest of a single
-  resource](./how-tos/usage.md#working-with-resources);
-- [Follow logs for a single resource](./how-tos/usage.md#following-logs)
+- [Display details](./how-tos/usage.md#working-with-resources), [follow
+  logs](./how-tos/usage.md#following-logs), and manage port-forwards for
+  resources;
 - [List collections of resources](./how-tos/usage.md#working-with-resources);
 - Start and stop [proxy servers](./how-tos/usage.md#managing-proxy-servers);
 - Use the menu bar to perform basic cluster/config management;

docs/references/changelog.md

@@ -18,6 +18,8 @@ versioning][semver].
   similar to `kubectl get deployments`
 - `kele-resource` now has a keybinding to follow logs for resources that support
   it
+- `kele-resource` now has a suffix for port-forwarding to resources that support
+  it
 
 ## 0.6.0
 

kele.el

@@ -110,6 +110,9 @@ pods."
 (defvar kele--loggable-kinds '("pods" "deployments" "jobs" "services")
   "Resource kinds that can be passed to kubectl log.")
 
+(defvar kele--port-forwardable-kinds '("pods" "deployments" "services")
+  "Resource kinds that can be passed to kubectl port-forward.")
+
 ;; TODO (#80): Display in the `kele-get-mode' header what fields were filtered out
 (defcustom kele-filtered-fields '((metadata managedFields)
                                   (metadata annotations kubectl.kubernetes.io/last-applied-configuration))
@@ -567,6 +570,16 @@ GROUP and VERSION are not always set.  KIND is always set."
         (concat (oref gvk group) "/" vk)
       vk)))
 
+(cl-defmethod kele--singular ((gvk kele--gvk) &optional context)
+  "Return the name of GVK in singular form.
+
+If CONTEXT is provided, look up in that context.  Otherwise, use
+the current context."
+  (kele--get-singular-for-plural
+   kele--global-discovery-cache
+   (oref gvk kind)
+   :context (or context (kele-current-context-name))))
+
 (cl-defstruct (kele--proxy-record
                (:constructor kele--proxy-record-create)
                (:copier nil))
@@ -1992,6 +2005,57 @@ to query for."
      (list (kele--get-context-arg) ns gvk name)))
   (kele--render-object (kele--get-resource gvk name :namespace namespace :context context)))
 
+(transient-define-suffix kele-port-forward (context namespace gvk name port)
+  "Create a port-forward for resource GVK named NAME at PORT.
+
+NAMESPACE and CONTEXT are used to identify the resource type to query for."
+  :key "F"
+  :description
+  "Port-forward to..."
+  :if
+  (lambda ()
+    (let-alist (oref transient--prefix scope)
+      (-contains? kele--port-forwardable-kinds .kind)))
+  (interactive
+   (let* ((gvk (kele--get-gvk-arg))
+          (context (kele--get-context-arg))
+          (ns (kele--get-namespace-arg
+               :kind (oref gvk kind)
+               :group-version (kele--gv-string gvk)
+               :use-default nil))
+          (cands (kele--fetch-resource-names gvk :namespace ns :context context))
+          (name (completing-read
+                 (format "%s to port-forward to: " (kele--singular gvk))
+                 (-cut kele--resources-complete <> <> <> :cands cands)))
+
+          ;; TODO: Completion on the resource's exposed ports
+          ;; TODO: Error if the port is already in use
+          (port (number-to-string (read-number "Port: "))))
+     (list context ns gvk name port)))
+  (let ((proc-name (format "kele: port-forward (%s/%s, %s, %s, %s)" (oref gvk kind) name context namespace port)))
+    (make-process
+     :name proc-name
+     :command (list kele-kubectl-executable
+                    "--context"
+                    context
+                    "--namespace"
+                    namespace
+                    "port-forward"
+                    (format "%s/%s" (oref gvk kind) name)
+                    port)
+     :buffer (generate-new-buffer (format " *%s*" proc-name))
+     :sentinel
+     (lambda (proc _status)
+       (let ((exit-code (process-exit-status proc)))
+         (cl-case exit-code
+           (0 (message "Successfully terminated port-forward for %s" name))
+           (9 (message "Port-forward for %s (port %s) terminated" name port))
+           (t (message "Port-forward process for %s failed with exit code %s" name exit-code)))
+         (kele--kill-process-quietly proc)))
+     :noquery t))
+  (message "[kele] Started port-forward for %s/%s (port %s)" (oref gvk kind) name port))
+
+
 (transient-define-suffix kele-deployment-restart (context namespace deployment-name)
   "Restart DEPLOYMENT-NAME.
 
@@ -2043,6 +2107,7 @@ CONTEXT and NAMESPACE are used to identify where the deployment lives."
                   (propertize it 'face 'warning))
              (propertize "-specific actions" 'face 'transient-heading))))
     (kele-resource-follow-logs)
+    (kele-port-forward)
     (kele-deployment-restart)]]
 
   (interactive (let* ((context (kele-current-context-name))