Add integrant repl for better development experience

- Create `user` ns for REPL-driven development.
- Add entry point in `example.server` to start server in production.

examples/ring-integrant/README.md

@@ -4,9 +4,17 @@ A Sample project with ring and reitit.
 
 ## Usage
 
-```clj
+Run Ring server in command line:
-> lein repl
+
-(start)
+```bash
+lein run
+```
+
+Run Ring server in the REPL
+
+```bash
+lein repl
+> (go)
 ```
 
 Go with browser to:

examples/ring-integrant/dev/user.clj

@@ -0,0 +1,15 @@
+(ns user
+  (:require
+   [integrant.repl :as ig-repl]
+   [example.server]))
+
+(ig-repl/set-prep! (constantly example.server/system-config))
+
+(def go ig-repl/go)
+(def halt ig-repl/halt)
+(def reset ig-repl/reset)
+
+(comment
+  (go)
+  (reset)
+  (halt))

examples/ring-integrant/project.clj

@@ -1,7 +1,10 @@
 (defproject ring-integrant-example "0.1.0-SNAPSHOT"
-  :description "Reitit Ring App with Swagger"
+  :description "Reitit Ring App with Integrant"
   :dependencies [[org.clojure/clojure "1.10.1"]
                  [ring/ring-jetty-adapter "1.7.1"]
                  [metosin/reitit "0.3.10"]
                  [integrant "0.7.0"]]
-  :repl-options {:init-ns example.server})
+  :main example.server
+  :repl-options {:init-ns user}
+  :profiles {:dev {:dependencies [[integrant/repl "0.3.1"]]
+                   :source-paths ["dev"]}})

examples/ring-integrant/src/example/server.clj

@@ -4,8 +4,6 @@
    [ring.adapter.jetty :as jetty]
    [integrant.core :as ig]))
 
-(defonce server (atom nil))
-
 (def system-config
   {:example/jetty   {:port    3000
                      :join?   false
@@ -24,12 +22,5 @@
    (ring/router
     ["/ping" {:get {:handler (fn [_] {:status 200 :body "pong!"})}}])))
 
-(defn start []
+(defn -main []
-  (reset! server (ig/init system-config)))
+  (ig/init system-config))
-
-(defn stop []
-  (swap! server ig/halt!))
-
-(comment
-  (start)
-  (stop))