Now where is that localhost..?

Running Parallels desktop on my MacBook, I figured I wanted to add as little as possible to my Windows installation. Just the necessary things to be able to do .Net development. Visual Studio and SQL Server. As to other databases, I should be able to use the instances already installed on my Mac.

So how to call the localhost of the other OS? Well, not too hard really. Since they're both on a shared network, I should just be able to use the IP-adresses. So first, we need to find them.

Finding the IP-address for the Mac host and using it on Windows

Go into the Parallels Desktop menu >> Preferences. Click the tab Advanced and then Network: Change settings. Check the box 'Show in System Preferences'.

Now you can go into the Apple menu >> System preferences >> Network and find the IP-address of the host under the Parallels network provider.

To check if this works, I started up a node server on my Mac, on localhost:4000.

I went in to my Windowsinstallation and tried to call it with the IP-number 10.211.55.2.

Great success! But of course, I don't want to remember that IP-number. So let's edit the hosts-file. And as always, when editing system files, don't forget to run notepad or whatnot as an administrator. The hosts-file, if you managed to avoid it this far, is located in C:\Windows\System32\drivers\etc.

Add the following line to the file: 

10.211.55.2     mac.localhost

Save it and you should now be able to call the service with mac.localhost instead. Yay!

Finding the IP-address for the Windows guest and using it on Mac

As you probably guess, you do the same thing. To get the IP-number for the Windows guest, go into Windows, start a Command window and type ipconfig. Look for the IPv4 Address.

Now go back to the Mac and find the hosts-file under /etc. Add the following line to the file:

10.211.55.3 win.localhost

And now you should be able to call the windows localhost from Mac using win.localhost.

ElasticSearch issue

After running Elastic Search on my Mac I wanted to use that instance for my Nancy API I was building on Windows. Since Elastic Search was running on localhost:9200 on the Mac, I assumed the above solution would work without problems. But nope, I just got a Website not found response when I tried to access mac.localhost:9200 in the browser. 

Since everything worked with my node server it seemed there wasn't an issue about firewalls or security. I tried some CORS-configuration for a while, thinking that might be the problem. It definitely seemed to have something to do with the Elastic Search configuration and setup. 

After quite a long while I found the thing. The Elastic Search config file elasticsearch.yml had the entry network.host: 127.0.0.1. Apparently this entry didn't care about the parallel network adapter at all. So I simply changed the entry to use that IP instead: 10.211.55.2 and restarted Elastic Search.

But wait! Now it works perfectly calling mac.localhost from Windows but I can't call localhost:9200 from the Mac! So another trip into both of the hosts files.

Now I have this in Windows:

10.211.55.3     win.localhost

10.211.55.2     mac.localhost

And this in Mac:

10.211.55.2 mac.localhost

10.211.55.3 win.localhost

All is well and I can develop my .Net-stuff and call services on the Mac. Very neat. I haven't tried the other way around yet, that might be a blogpost for another day.