ASP.NET Core 2.2 REST API #14 — Running in Docker

Up Next: Integration Testing

Using a docker file and docker compose. This is not a docker tutorial.

Just create a Dockerfile in the root project directory.

If you select to create a new project with docker support this is pretty much what is going to be generated from visual studio (.Net Core 2.0+)

The Dockerfile

• Start by using Microsoft’ s .net core base image FROM microsoft/dotnet:2.2-sdk as build from dockerhub
• ARG BUILDCONFIG=RELEASE to use the release (not debug) .net core version
• ARG VERSION=1.0.0 for semantic versioning of the image
• COPY Tweetbook.csproj /build/
• RUN dotnet restore ./build/Tweetbook.csproj to download/restore all the dependencies of the project
• COPY . ./build copy all the project into the build directory
• WORKDIR /build/
• RUN dotnet publish ./Tweetbook.csproj -c $BUILDCONFIG -o out /p:Version=$VERSION to build it into the /out directory
• Use the FROM microsoft/dotnet:2.2-aspnetcore-runtime in order to use the production ready .net core runtime
• WORKDIR /app
• COPY --from=build /build/out .
• ENTRYPOINT ["dotnet", "Tweetbook.dll"]

That’s all for the app, but we still need to instantiate some database container. It’s a very bad practise to use a single docker file to mix both the application and the database or other services in the same Dockerfile . That’s a job for

Docker compose

Go into the Solution level and create a new docker-compose.yml .

Let’s use version: '3.5' and let’s get started:

• Create a network for development purposes
• Register our Tweetbook api that depends on the database server
• Register our database mssql server along with the credentials

Change the database connection string to ”DefaultConnection”: “Server=(localdb)\\mssqllocaldb;Database=Tweetbook;Trusted_Connection=True;MultipleActiveResultSets=true”

If we go to the docker-compose.yml ‘s directory and run docker-compose build and docker-compose up we are going to see everything spinning up smoothly.

Everything is up and running at localhost:7000 .

Up Next: Integration Testing

Code is available on Github and the instructional videos are located on YouTube.

Keep Coding