Dotnet Core Web Api, Docker, Consul & Registrator

Introduction

       In this article I am going to provide step by step tutorial for creating docker image for docker web api, consul for service registry and discovery, registrator for registering the docker service.

Prerequisites

• Sample Web api application is ready and available in working condition in dotnet core.
• Docker installed on the system.

Steps:

  #1: Create a docker file Dockerfile. in bin /Release folder parallel to PublishOutput folder.

  

#2: Put the below text inside Dockerfile.

FROM microsoft/dotnet:onbuild
WORKDIR /app
Add PublishOutput /app/
ENV ASPNETCORE_URLS http://*:5001
EXPOSE 5001
RUN dotnet restore
ENTRYPOINT ["dotnet",".dll"]

#3: Open command prompt pointing to the same path as Dockerfile and then run the below command

 >docker build -t <servicename> .

 docker images will be created.

>docker images

will list your image

#4: run the docker run command to execute the service

>docker run -d -p 80:5001 servicename

Now browse the service 

#5: now stop the docker container

#6: pull the consul & registrator images from hub

>docker pull gliderlabs/consul-server:latest

>docker pull gliderlabs/registrator:latest

#7: run the container for consul

>docker run -d --name=consul -p 8300:8300 -p 8500:8500  gliderlabs/consul-server -bootstrap -advertise=127.0.0.1

#8:run the container for the registrator

>docker run -d --name=registrator  --volume=/var/run/docker.sock:/tmp/docker.sock gliderlabs/registrator:latest consul://localhost:8500

#9: Now run the docker container for the web api

>docker start <containerId for webapi>

#10: Browse localhost:8500/ui and click on the services, new service will be listed there.

#11. Now client application of web api service can use the consul nuget package to discover the service.

var _services =new List<Uri>();

            var consulClient = new ConsulClient(c => c.Address = new Uri("http://127.0.0.1:8500"));

            var services = consulClient.Agent.Services().Result.Response;

            foreach (var service in services)

            {

                

                var isServiceAvailable = service.Value.Service(

                if (isSchoolApi)

                {

                    var serviceUri = new Uri($"{service.Value.Address}:{service.Value.Port}");

                    _serverUrls.Add(serviceUri);

                }

            }