Update Pipeline to create and push docker image (#61)

# Why is this change being made?
So we can automatically generate docker images and push them to a container registry.

# What changed?

- Updated the pipeline to have: 
    - A task to get the build start time for the tag of the docker image.
    - A buildAndPush task which creates and pushes an image to docker hub. We're currently using my private docker hub while we figure out where we want these images to be pushed.

- Updated the documentation to fix some errors and added some information on how to use these new docker images.
- Changed DockerFile copy path from Debug to Release since the pipeline builds release.
Not in this PR:
- Added a service connection so the Azure pipeline can communicate with the dockerhub from this pipeline config.

# How was this validated?
Created a duplicate pipeline for my fork of this repo. I then validated by creating a commit that the image ended up on the docker hub and followed the instructions that I added to validate that the container could be run.

Author: Mathos1432

Dockerfile

@@ -4,7 +4,7 @@
 
 FROM mcr.microsoft.com/dotnet/sdk:5.0
 # TODO once we have a story for release process, change this to release
-COPY Cosmos.GraphQL.Service/Cosmos.GraphQL.Service/bin/Debug/net5.0 /App
+COPY Cosmos.GraphQL.Service/Cosmos.GraphQL.Service/bin/Release/net5.0 /App
 WORKDIR /App
 ENV ASPNETCORE_URLS=http://+:5000
 ENTRYPOINT ["dotnet", "Cosmos.GraphQL.Service.dll"]

build-pipelines.yml

@@ -49,3 +49,25 @@ steps:
     command: test
     projects: '**/*Tests/*.csproj'
     arguments: '--filter "TestCategory!=Cosmos&TestCategory!=MsSql" --configuration $(buildConfiguration)'
+
+# This task gets the current date and saves it to a variable so the docker task can use the build's 
+# date and time as a tag.
+- task: PowerShell@2
+  displayName: "Get date for Docker image Tag"
+  inputs:
+    targetType: 'inline'
+    script: |
+      Write-Host "Setting up the date and time as a build variable for the Docker tag"
+      $date=$(Get-Date -format yyyyMMdd-HHmmss)
+      Write-Host "##vso[task.setvariable variable=BuildDate]$date"
+
+# Build a docker image and push it to the container registry. This is a temporary location until
+# we close on where we want these images to live.
+- task: Docker@2
+  displayName: "Build and push docker image to docker hub"
+  inputs:
+    containerRegistry: 'CosmosDB-GraphQL-TempDockerHub'
+    repository: 'matrembl/graphql'
+    command: 'buildAndPush'
+    Dockerfile: '**/Dockerfile'
+    tags: '$(BuildDate)-$(Build.SourceVersion)' # Use build date and commitId as the tag for the image

docs/GetStarted.md

@@ -1,7 +1,25 @@
 # Introduction
 
+# Deploy docker container from DockerHub (Prebuilt image)
+N.B. This section only applies if you want to use a prebuilt image, if you want to build it yourself, move on to the next section (Build and deploy as Docker Container)
 
-# Deploy as Docker Container
+N.B. The image is currently hosted in a temporary location, so you might not have access to it. 
+
+1. Pull the docker image:
+```bash
+docker pull matrembl/graphql:20211019-154145 # Note to update to the correct tag
+```
+2. Update the config.json and the appsettings.json files with your connection strings and the resolvers
+
+3. Launch the docker container and map the config.json and appsettings.json files. The command should look something like this (depending on the path to your appsettings and config files, and the image you are using):
+
+```bash
+docker run --mount type=bind,source="$(pwd)\Cosmos.GraphQL.Service\Cosmos.GraphQL.Service\appsettings.json",target="/App/appsettings.json" --mount type=bind,source="$(pwd)\Cosmos.GraphQL.Service\Cosmos.GraphQL.Service\config.json",target="/App/config.json" -d -p 5000:5000 matrembl/graphql:20211019-154145
+# Note to update to the correct tag
+```
+4. The container should be accessible at localhost:5000
+
+# Build and deploy as Docker Container
 
 ## Build Image
 
@@ -48,9 +66,9 @@ docker tag multiverse-datagateway multiverseacr.azurecr.io/multiverse-datagatewa
 Login to the ACR with the correct credentials
 ```bash
 docker login multiverseacr.azurecr.io
-````
+```
 
 Push the retagged image
 ```bash
 docker push multiverseacr.azurecr.io/multiverse-datagateway
-``
+```