Adding flexibility on network, and including docker service name, if …

…there
michaellwest · Dec 17, 2019 · e6b1112 · e6b1112
1 parent a564b2d
commit e6b1112
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Showing 3 changed files with 31 additions and 7 deletions.
diff --git a/Program.cs b/Program.cs
@@ -11,19 +11,28 @@ namespace windows_hosts_writer
     class Program
     {
         private const string ENV_ENDPOINT = "endpoint";
+        private const string ENV_NETWORK = "network";
         private const string ENV_HOSTPATH = "hosts_path";
         private const string ERROR_HOSTPATH = "could not change hosts file at {0} inside of the container. You can change that path through environment variable " + ENV_HOSTPATH;
         private const string EVENT_MSG = "got a {0} event from {1}";
+        private static string LISTEN_NETWORK = "nat";
         private static DockerClient _client;
         private static bool _debug = false;
 
         static void Main(string[] args)
         {
-            if (Environment.GetEnvironmentVariable("debug") != null) {
+            if (Environment.GetEnvironmentVariable("debug") != null)
+            {
                 _debug = true;
                 Console.WriteLine("Starting Windows hosts writer");
             }
 
+            if (Environment.GetEnvironmentVariable(ENV_NETWORK) != null)
+            {
+                LISTEN_NETWORK = Environment.GetEnvironmentVariable(ENV_NETWORK);
+            }
+
+
             var progress = new Progress<Message>(message =>
             {
                 if (message.Action == "connect")
@@ -116,7 +125,7 @@ private static void HandleHosts(bool add, Message message)
                         Console.WriteLine(ERROR_HOSTPATH, hostsPath);
                         return;
                     }
-                    catch (IOException)
+                    catch (IOException ex)
                     {
                         if (tryCount == 5)
                         {
@@ -130,11 +139,12 @@ private static void HandleHosts(bool add, Message message)
                 if (message.Actor.Attributes["type"] == "nat")
                 {
                     var containerId = message.Actor.Attributes["container"];
-                    try {
+                    try
+                    {
                         var response = GetClient().Containers.InspectContainerAsync(containerId).Result;
                         var networks = response.NetworkSettings.Networks;
                         EndpointSettings network = null;
-                        if (networks.TryGetValue("nat", out network))
+                        if (networks.TryGetValue(LISTEN_NETWORK, out network))
                         {
                             var hostsLines = new List<string>();
                             using (StreamReader reader = new StreamReader(hostsFileStream))
@@ -145,16 +155,24 @@ private static void HandleHosts(bool add, Message message)
 
                                 hostsFileStream.Position = 0;
                                 var removed = hostsLines.RemoveAll(l => l.EndsWith($"#{containerId} by whw"));
+                                var hostnames = response.Config.Hostname;
+
+                                if (response.Config.Labels.ContainsKey("com.docker.compose.service"))
+                                {
+                                    hostnames += $" {response.Config.Labels["com.docker.compose.service"]}";
+                                }
 
                                 if (add)
-                                    hostsLines.Add($"{network.IPAddress}\t{response.Config.Hostname}\t\t#{containerId} by whw");
+                                    hostsLines.Add($"{network.IPAddress}\t{hostnames}\t\t#{containerId} by whw");
 
                                 foreach (var line in hostsLines)
                                     writer.WriteLine(line);
                                 hostsFileStream.SetLength(hostsFileStream.Position);
                             }
                         }
-                    } catch (Exception ex) {
+                    }
+                    catch (Exception ex)
+                    {
                         if (_debug)
                         {
                             Console.WriteLine("Something went wrong. Maybe looking for a container that is already gone? Exception is " + ex.Message);

diff --git a/README.md b/README.md
@@ -1,4 +1,10 @@
 # windows-hosts-writer
+
+###Updated: 12-17-19
+- Allows for configuration of the network to monitor.  Set the "network" environment variable
+- Adds the docker compose service name (for better user experience)
+
+
 Small tool that monitors the Docker engine and modifies the hosts file on Windows to allow easier networking
 
 You can run this natively as well but as you need to have Docker running anyways to use it, the easiest way is:

diff --git a/windows-hosts-writer.csproj b/windows-hosts-writer.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.2</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <RootNamespace>windows_hosts_writer</RootNamespace>
   </PropertyGroup>