Docker File Sample

Question 1

Where does the docker file reside?

Answer 1

In root of the applciation

Question 2

Pull ASP.NET Core 3.1 runtime and give the name ‘base’

Answer 2

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1 AS base

Question 3

Set the ports where the container listens at runtime

Answer 3

EXPOSE 80
EXPOSE 443

Question 4

Pull the ASP.NET Core 3.1 SDK and give the name ‘build’

Answer 4

FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS build

Question 5

What is the WORKDIR instruction?

Answer 5

The WORKDIR instruction sets the working directory for any RUN, CMD, ENTRYPOINT, COPY and ADD instructions that follow

Question 6

Set the Working Dir to ‘/src’.
This is where the source code is.

Answer 6

WORKDIR /src

Question 7

Copy projects

Answer 7

COPY [“Name.Of.Your.Project.csproj”, “Name.Of.Your.Project/”]
COPY [“Dependancy.Of.Your.Project.csproj”, “Dependancy.Of.Your.Project/”]

Question 8

Run the application in a shell, in this case run ‘dotnet restore’

Answer 8

RUN dotnet restore “Name.Of.Your.Project/”Name.Of.Your.Project.csproj”

WORKDIR “/src/”Name.Of.Your.Project”
COPY . .
RUN dotnet build “Name.Of.Your.Project.csproj” -c Release -o /app/build

Question 9

Run the publish command using the SDK named as ‘build’

Answer 9

FROM build AS publish
RUN dotnet publish “Name.Of.Your.Project.csproj” -c Release -o /app/publish

Question 10

Pull ‘base’ image and name it as ‘final’ to allow pull access for publish

Answer 10

FROM base AS final
WORKDIR /app
COPY –from=publish /app/publish .

Question 11

Set the entry point, in other words, what to run!

Answer 11

ENTRYPOINT [“dotnet”, “Name.Of.Your.Project.dll”]