add service control

src/stream/commander/impl.clj

@@ -4,7 +4,18 @@
             [taoensso.timbre :as timbre
              :refer [log  trace  debug  info  warn  error  fatal  report
                      logf tracef debugf infof warnf errorf fatalf reportf
-                     spy get-env]]))
+                     spy get-env]])
+  (:import [de.thjom.java.systemd Systemd Manager Systemd$InstanceType UnitStateListener]))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+                                        ;          Systemd Instances          ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;; These are instanciated toplevel and are allowed to crash the
+;; program if not successfull.
+
+(def ^:private systemd (. Systemd get Systemd$InstanceType/USER))
+(def ^:private manager (. systemd getManager))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
                                         ;         Unit file Management        ;
@@ -20,14 +31,89 @@
                              :command command
                              :target target}))
 
+(defn get-unit-path [name]
+  (str (System/getProperty "user.home") "/.config/systemd/user/" name ".service"))
+
 (defn create-unit-file!
   "Creates or overwrites a service unit file in the appropriate
   directory and returns the file path."
+  ([name command description]
+   (create-unit-file! name command description "default.target"))
+  ([name command description target]
+   (let [unit-contents (render-unit-file command description target)
+         path (get-unit-path name)
+         file (io/as-file path)]
+     (.mkdirs (.getParentFile file))
+     (spit path unit-contents)
+     (debug "Wrote a unit file to:" path)
+     path)))
+
+
+(defn remove-unit-file!
+  "Removes the unit file with the given name. Returns true if file was
+  deleted."
+  [name]
+  (let [path (get-unit-path name)]
+    (debug "Deleting a unit file:" path)
+    (.delete (io/as-file path))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+                                        ;           Systemd Handling          ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;; For now these work with the service name. May be generalized to a
+;; record some time.
+
+(defn reload-systemd!
+  "Reloads the systemd user instance."
+  []
+  (. manager reload))
+
+(defn- get-service! [name]
+  (. manager getService name))
+
+(defn start-service!
+  "Starts the userspace service with the name."
+  [name]
+  (. (get-service! name) start "replace"))
+
+(defn restart-service!
+  "Restarts the userspace service with the name."
+  [name]
+  (. (get-service! name) restart "replace"))
+
+(defn stop-service!
+  "Stops the userspace service with the name."
+  [name]
+  (. (get-service! name) stop "replace"))
+
+(defn get-service-status!
+  "Gets the ActiveState for the process of the name.
+
+  Refer to
+  [the systemd docs](https://www.freedesktop.org/wiki/Software/systemd/dbus/)
+  for further information."
+  [name]
+  (keyword (. (get-service! name) getActiveState)))
+
+(defn get-service-load-state!
+  "Gets the LoadState for the process of the name.
+
+  Refer to
+  [the systemd docs](https://www.freedesktop.org/wiki/Software/systemd/dbus/)
+  for further information."
+  [name]
+  (keyword (. (get-service! name) getLoadState)))
+
+(defn create-service!
+  "Creates a unit file and reloads systemd. See `create-unit-file`."
   [name command description target]
-  (let [unit-contents (render-unit-file command description target)
-        path (str (System/getProperty "user.home") "/.config/systemd/user/" name ".service")
-        file (io/as-file path)]
-    (.mkdirs (.getParentFile file))
-    (spit path unit-contents)
-    (debug "Wrote a unit file to:" path)
-    path))
+  (create-unit-file! name command description target)
+  (reload-systemd!))
+
+(defn remove-service!
+  "Stops the service, removes the unit file and reloads systemd."
+  [name]
+  (stop-service! name)
+  (remove-unit-file! name)
+  (reload-systemd!))

test/stream/commander_test.clj

@@ -7,10 +7,35 @@
 (deftest unit-files
   (testing "The rendering."
     (is (#'impl/render-unit-file "test" "test" "test")))
+
   (let [name (str (java.util.UUID/randomUUID))]
     (testing "Writing a unit file."
       (let [file (io/as-file
                   (impl/create-unit-file! name
                                           "test" "test" "test"))]
-        (is (.exists file))
-        (.delete file)))))
+        (is (.exists file))))
+
+    (testing "Deleting a unit file"
+      (impl/remove-unit-file! name)
+      (is (not (.exists (io/as-file (impl/get-unit-path name))))))))
+
+(deftest systemd-services
+  (let [name (str (java.util.UUID/randomUUID))
+        unit-path (impl/create-unit-file! name
+                                          "cat /dev/zero" "test service")]
+    (testing "loading the service"
+      (is :not-found (impl/get-service-load-state! name))
+      (impl/reload-systemd!)
+      (is :loaded (impl/get-service-load-state! name)))
+
+    (testing "starting the service"
+      (impl/start-service! name)
+      (is :active (impl/get-service-load-state! name)))
+
+    (testing "stopping the service"
+      (impl/stop-service! name)
+      (is :inactive (impl/get-service-load-state! name)))
+
+    (testing "removing the service"
+      (impl/remove-service! name)
+      (is :not-found (impl/get-service-load-state! name)))))