First, you'll need to install dotnet core on your mac. You can easily do this by following the instructions here: https://www.microsoft.com/net/learn/get-started-with-dotnet-tutorial
Next, create a simple new web application. I chose a webapi application, because I wanted to create an example API running in Kubernetes. I passed a flag to not have any auth turned on by default, and no https turned on by defaults: dotnet new webapi --auth None --no-https.
The output of that is something like what's shown below..
~/dev/src/github.com/karthequian/dotnet-example$ dotnet new webapi --auth None --no-https
The template "ASP.NET Core Web API" was created successfully.
Processing post-creation actions...
Running 'dotnet restore' on /Users/karthik/dev/src/github.com/karthequian/dotnet-example/dotnet-example.csproj...
Restoring packages for /Users/karthik/dev/src/github.com/karthequian/dotnet-example/dotnet-example.csproj...
Generating MSBuild file /Users/karthik/dev/src/github.com/karthequian/dotnet-example/obj/dotnet-example.csproj.nuget.g.props.
Generating MSBuild file /Users/karthik/dev/src/github.com/karthequian/dotnet-example/obj/dotnet-example.csproj.nuget.g.targets.
Restore completed in 1.42 sec for /Users/karthik/dev/src/github.com/karthequian/dotnet-example/dotnet-example.csproj.
Restore succeeded.
This will effectively create the shell for your project (csproj), and everything you'll see in the github project..
Type dotnet run to run it locally on your mac. The initial build took a little long, but it was up and running pretty quick. The output of the command is shown below:
~/dev/src/github.com/karthequian/dotnet-example$ dotnet run
Using launch settings from /Users/karthik/dev/src/github.com/karthequian/dotnet-example/Properties/launchSettings.json...
: Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[0]
User profile is available. Using '/Users/karthik/.aspnet/DataProtection-Keys' as key repository; keys will not be encrypted at rest.
Hosting environment: Development
Content root path: /Users/karthik/dev/src/github.com/karthequian/dotnet-example
Now listening on: http://localhost:5000
Application started. Press Ctrl+C to shut down.
To test the application, you can run a simple curl against it, or open up the URL in the website. As there are no default routing paths for /, and there is only a controller defined for /values, we'll need to make sure to curl against a /values endpoint as shown below, and we should see what we expect.
~/dev/src/github.com/karthequian/dotnet-example$ curl localhost:5000/api/values/
["value1","value2"]
I've included a sample Dockerfile with this, that'll work well for the application. I followed the example to build this from the Docker website: https://docs.docker.com/engine/examples/dotnetcore/#create-a-dockerfile-for-an-aspnet-core-application. I did make a change to the Entrypoint, and updated the dll name to match the project name, which, in this case is dotnet-example.dll
To build, I ran the following docker build command, and tagged it with my dockerhub name.
~/dev/src/github.com/karthequian/dotnet-example$ docker build -t karthequian/dotnetexample .
Sending build context to Docker daemon 1.37MB
Step 1/10 : FROM microsoft/dotnet:sdk AS build-env
---> 9e243db15f91
Step 2/10 : WORKDIR /app
---> Using cache
---> f9654a9137e0
Step 3/10 : COPY *.csproj ./
---> Using cache
---> 3269eb744d01
Step 4/10 : RUN dotnet restore
---> Using cache
---> a7f034c5b6bb
Step 5/10 : COPY . ./
---> be9452f1d481
Step 6/10 : RUN dotnet publish -c Release -o out
---> Running in d3fbd21bf58c
Microsoft (R) Build Engine version 15.7.179.6572 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.
Restoring packages for /app/dotnet-example.csproj...
Generating MSBuild file /app/obj/dotnet-example.csproj.nuget.g.props.
Generating MSBuild file /app/obj/dotnet-example.csproj.nuget.g.targets.
Restore completed in 621.9 ms for /app/dotnet-example.csproj.
dotnet-example -> /app/bin/Release/netcoreapp2.1/dotnet-example.dll
dotnet-example -> /app/out/
---> f5b878778afd
Removing intermediate container d3fbd21bf58c
Step 7/10 : FROM microsoft/dotnet:aspnetcore-runtime
---> fcc3887985bb
Step 8/10 : WORKDIR /app
---> Using cache
---> 6d69aad275ab
Step 9/10 : COPY --from=build-env /app/out .
---> Using cache
---> 2788fd5829f9
Step 10/10 : ENTRYPOINT dotnet dotnet-example.dll
---> Running in 12bfee8e072d
---> 15a64794811d
Removing intermediate container 12bfee8e072d
Successfully built 15a64794811d
Successfully tagged karthequian/dotnetexample:latest
Next, to verify this works, I can run the container with the command docker run -d -p 5001:80 karthequian/dotnetexample, and port maps port 5000 on my machine to port 80 on the container. And again, I can test this with a curl command as shown below, where localhost:5000 is pointed to my container by Docker.
~/dev/src/github.com/karthequian/dotnet-example$ curl localhost:5001/api/values
["value1","value2"]
I've created a sample Deployment.yaml file with this project that you can use. Once you've got a kubernetes cluster running, such as a cluster in Oracle Kubernetes Engine, you can run the command below to deploy the container to Kubernetes:
kubectl apply -f https://raw.githubusercontent.com/karthequian/dotnet-example/master/Deployment.yaml
This will make a deployment and a service, and will expose the service as a nodeport on port 32080.
~/dev/src/github.com/karthequian/dotnet-example$ kubectl apply -f https://raw.githubusercontent.com/karthequian/dotnet-example/master/Deployment.yaml
deployment "dotnetworld" created
service "dotnetworld" created
~/dev/src/github.com/karthequian/dotnet-example$ kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
dotnetworld 1 1 1 1 20s
~/dev/src/github.com/karthequian/dotnet-example$ kubectl get services
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
dotnetworld 10.96.79.93 <nodes> 80:32080/TCP 26s
kubernetes 10.96.0.1 <none> 443/TCP 30d
To test, you can get the IP of any of the nodes on your service, and then run a curl against it like the examples below.
~/dev/src/github.com/karthequian/dotnet-example$ kubectl get services
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
dotnetworld 10.96.79.93 <nodes> 80:32080/TCP 26s
kubernetes 10.96.0.1 <none> 443/TCP 30d
~/dev/src/github.com/karthequian/dotnet-example$ kubectl get nodes
NAME STATUS AGE VERSION
129.146.123.174 Ready 30d v1.9.7
129.146.133.234 Ready 30d v1.9.7
129.146.162.102 Ready 30d v1.9.7
~/dev/src/github.com/karthequian/dotnet-example$ curl 129.146.162.102:32080/api/values
["value1","value2"]
And there you have it, a dotnet core app running in Kubernetes! If you run into issues, feel free to create a github issue against me, or reach me on twitter via @iteration1