Update ElasticManager constructor auto IP config (#190)

* Update Elastic auto IP config

* Update ElasticManager auto IP platforms

Project.toml

@@ -9,7 +9,7 @@ Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 Sockets = "6462fe0b-24de-5631-8697-dd941f90decc"
 
 [compat]
-julia = "1"
+julia = "1.2"
 
 [extras]
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"

README.md

@@ -151,7 +151,7 @@ ElasticManager(addr, port) = ElasticManager(;addr=addr, port=port)
 ElasticManager(addr, port, cookie) = ElasticManager(;addr=addr, port=port, cookie=cookie)
 ```
 
-On Linux and Mac, you can set `addr=:auto` to automatically use the host's private IP address on the local network, which will allow other workers on this network to connect. You can also use `port=0` to let the OS choose a random free port for you (some systems may not support this). Once created, printing the `ElasticManager` object prints the command which you can run on workers to connect them to the master, e.g.:
+You can set `addr=:auto` to automatically use the host's private IP address on the local network, which will allow other workers on this network to connect. You can also use `port=0` to let the OS choose a random free port for you (some systems may not support this). Once created, printing the `ElasticManager` object prints the command which you can run on workers to connect them to the master, e.g.:
 
 ```julia
 julia> em = ElasticManager(addr=:auto, port=0)

src/elastic.jl

@@ -18,8 +18,13 @@ struct ElasticManager <: ClusterManager
         Distributed.init_multi()
         cookie !== nothing && cluster_cookie(cookie)
 
+        # Automatically check for the IP address of the local machine
         if addr == :auto
-            addr = get_private_ip()
+            try
+                addr = Sockets.getipaddr(IPv4)
+            catch
+                error("Failed to automatically get host's IP address. Please specify `addr=` explicitly.")
+            end
         end
 
         l_sock = listen(addr, port)
@@ -134,25 +139,6 @@ function elastic_worker(cookie, addr="127.0.0.1", port=9009; stdout_to_master=tr
     start_worker(c, cookie)
 end
 
-
-function get_private_ip()
-    if Sys.islinux()
-        cmd = `hostname --ip-address`
-    elseif Sys.isapple()
-        cmd = `ipconfig getifaddr en0`
-    else
-        error("`addr=:auto` is only supported on Linux and Mac")
-    end
-    try
-        return IPv4(first(split(strip(read(cmd, String)))))
-    catch err
-        error("""Failed to automatically get host's IP address (output below). Please specify `addr=` explicitly.
-        \$ $(repr(cmd))
-        $err
-        """)
-    end
-end
-
 function get_connect_cmd(em::ElasticManager; absolute_exename=true, same_project=true)
 
     ip = string(em.sockname[1])