Add DigitalOcean util example [skip ci] (#673)

examples/README.md

@@ -381,3 +381,15 @@ Example usage:
 ``` shell
 $ cat src/babashka/main.clj | bb examples/rofi.clj
 ```
+
+### [digitalocean-ping.clj](digitalocean-ping.clj)
+
+The script allows to define which DigitalOcean cloud datacenter (region) has best network performance (ping latency).
+
+See [digitalocean-ping.clj](digitalocean-ping.clj)
+
+Example usage:
+
+``` shell
+$ bb digitalocean-ping.clj
+```

examples/digitalocean-ping.clj

@@ -0,0 +1,30 @@
+#!/usr/bin/env bb
+
+(require '[babashka.curl :as curl]
+         '[clojure.java.shell :as shell]
+         '[clojure.string :as str])
+
+(def url "http://speedtest-ams2.digitalocean.com/")
+
+(def get-endpoints
+  (let [{:keys [body]} (curl/get url)]
+    (re-seq #"speedtest\-.+.digitalocean.com" body)))
+
+(defn get-average [result]
+  (-> result
+      str/split-lines
+      last
+      (str/split #"/")
+      (get 4)))
+
+(def mac? (str/starts-with? (System/getProperty "os.name") "Mac"));; TODO: test on Windows
+
+(def timeout-arg (if mac? "-t3" "-w3"))
+
+(defn ping-result [endpoint]
+  (let [{:keys [out]} (shell/sh "ping" "-c5" timeout-arg endpoint)
+        msg (str endpoint " => " (get-average out) "ms")]
+    (println msg)))
+
+(doseq [endpoint get-endpoints]
+  (ping-result endpoint))