In my last blog, I mentioned a basic Web App that I had put together using Visual Studio 2015 tooling for .NET Core. Over the last couple of days, I’ve been looking at publishing the App, and the steps involved.
.NET Core is a new beast with a lot of potential…. the aim is it will run anywhere, on anything. So to keep my costs down, I’m going to trial it on my Amazon Linux VM. Note to self, SQL Server for Linux is about 1 year down the track – unfortunate, as the MVC scaffold uses SQL Server LocalDB – so I’ll have to figure out what database I can use.
But, first things first… how to publish my App to Linux?
First step – publish the App using dotnet publish. I found that Bower was not referenced in my Path environment variable. Bower was installed with Visual Studio 2015 Professional – in a sub-folder of my Visual Studio 2015 folder. I’m not sure if it was installed because I had installed tooling for .NET Core, or if it comes by default. Anyway, once that was sorted, dotnet publish worked fine and it created a portable for me to use.
I copied all of the files in the folder that dotnet publish created over to my Amazon Linux server. (I used WinSCP for this). Then I found I needed to install .NET Core on Amazon Linux. Installation was easy but when I tried to run the dotnet CLI, I received an error. Running dotnet –info from a bash shell I saw,
dotnet: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.18′ not found (required by dotnet)
After several hours of searching, I found this was due to the libstdc++ library version on my Amazon Linux distribution, which was libstdc++47. I had ensured my VM was up to date, so it seems that the libstc++ version was lagging (for whatever reason). After running the below, I was able to successfully run the dotnet CLI, with a valid response from dotnet –info.
sudo yum install libstdc++48
So, I had installed .NET core and fixed up the reference library it needed. After that, I needed a way to access my Web App. Kestrel is a web server built into .NET Core and can listen on any port you tell it to. However, it is better to use a web server as a proxy/reverse-proxy to relay request/response to Kestrel.
I already had a web server on my Amazon Linux VM. So I configured it with proxy and reverse-proxy mappings (to the Kestrel server in my .NET Core App). The calls to my web server forward on to the Kestrel server in the App, and vice-versa. I ran the App with dotnet run and checked access via the web server. All good 🙂
Almost there.
Finally, I installed supervisor to manage start/stop/restart of my App. And set up a script to ensure supervisor is re-started whenever my Amazon Linux machine restarts.
Note, this would have taken days if not for the early groundwork of several people who blog their efforts.
Now I have a Web App but no database. So next step is to get the database up and running.
Chris Cormack - Tech Stuff 