LBH Base API

Base API is a boilerplate code for being reused for new APIs for LBH

Stack

• .NET Core as a web framework.
• nUnit as a test framework.

Dependencies

• Universal Housing Simulator

Contributing

Setup

1. Install Docker.
2. Install AWS CLI.
3. Clone this repository.
4. Rename the initial template.
5. Open it in your IDE.

Renaming

The renaming of base-api into SomethingElseApi can be done by running a Renamer powershell script. To do so:

1. Open the powershell and navigate to this directory's root.
2. Run the script using the following command:

.\Renamer.ps1 -apiName My_Api

If your script execution policy prevents you from running the script, you can temporarily bypass that with:

powershell -noprofile -ExecutionPolicy Bypass -file .\Renamer.ps1 -apiName My_Api

Or you can change your execution policy, prior to running the script, permanently with (this disables security so, be cautious):

Set-ExecutionPolicy Unrestricted

After the renaming is done, the script will ask you if you want to delete it as well, as it's useless now - It's your choice.

Development

To serve the application, run it using your IDE of choice, we use Visual Studio CE and JetBrains Rider on Mac.

The application can also be served locally using docker:

1. Add you security credentials to AWS CLI.

$ aws configure

2. Log into AWS ECR.

$ aws ecr get-login --no-include-email

3. Build and serve the application. It will be available in the port 3000.

$ make build && make serve

Release process

We use a pull request workflow, where changes are made on a branch and approved by one or more other maintainers before the developer can merge into master branch.

Then we have an automated six step deployment process, which runs in CircleCI.

1. Automated tests (nUnit) are run to ensure the release is of good quality.
2. The application is deployed to development automatically, where we check our latest changes work well.
3. We manually confirm a staging deployment in the CircleCI workflow once we're happy with our changes in development.
4. The application is deployed to staging.
5. We manually confirm a production deployment in the CircleCI workflow once we're happy with our changes in staging.
6. The application is deployed to production.

Our staging and production environments are hosted by AWS. We would deploy to production per each feature/config merged into master branch.

Static Code Analysis

Using FxCop Analysers

FxCop runs code analysis when the Solution is built.

Both the API and Test projects have been set up to treat all warnings from the code analysis as errors and therefore, fail the build.

However, we can select which errors to suppress by setting the severity of the responsible rule to none, e.g dotnet_analyzer_diagnostic.<Category-or-RuleId>.severity = none, within the .editorconfig file. Documentation on how to do this can be found here.

Adding a migration

For this API we have a database in RDS, we are using EF Core Code first migrations to manage the schema for this database. To make changes to the database structure follow these steps.

1. If you haven't done so previously, you need to install the dotnet ef cli tool by running dotnet tool install --global dotnet-ef.
2. Make the necessary changes to the database model in the code, namely in DatabaseContext or any of the DbSet's listed in the file.
3. In your terminal navigate to the project root folder and run dotnet ef migrations add -o ./V1/Infrastructure/Migrations -p LBHFSSPublicAPI [NameOfThisMigration] to create the migration files. NameOfThisMigration should be replaced with your migration name e.g. AddColumnNameToPeopleTable.
4. Go to the folder /LBHFSSPublicAPI/V1/Infrastructure/Migrations and you should see two new files for the migration. In the one which doesn't end in .Designer you can check through the migration script to make sure everything is being created as you expect.
5. If the migration file looks wrong or you have missed something, you can either run CONNECTION_STRING="Host=127.0.0.1;Database=testdb;Username=postgres;Password=mypassword;" dotnet ef migrations remove -p LBHFSSPublicAPI with the database in the connection string running or just delete the migration files and revert the changes to DatabaseContextModelSnapshot.cs. Make the necessary changes to the context, then create the migration files again.
6. The CircleCI configuration file has been set up to run any new migrations to the specified AWS RDS database prior to deploying the API.

Note: You must not change any DbSet that is listed in DatabaseContext without creating a migration as the change then won't be reflected in the database and will cause errors.

Testing

Run the tests

$ make test

To run database tests locally (e.g. via Visual Studio) the CONNECTION_STRING environment variable will need to be populated with:

Host=localhost;Database=testdb;Username=postgres;Password=mypassword"

Note: The Host name needs to be the name of the stub database docker-compose service, in order to run tests via Docker.

Agreed Testing Approach

• Use nUnit, FluentAssertions and Moq
• Always follow a TDD approach
• Tests should be independent of each other
• Gateway tests should interact with a real test instance of the database
• Test coverage should never go down
• All use cases should be covered by E2E tests
• Optimise when test run speed starts to hinder development
• Unit tests and E2E tests should run in CI
• Test database schemas should match up with production database schema
• Have integration tests which test from the PostgreSQL database to API Gateway

Data Migrations

A good data migration

• Record failure logs
• Automated
• Reliable
• As close to real time as possible
• Observable monitoring in place
• Should not affect any existing databases

Contacts

Active Maintainers

• Selwyn Preston, Lead Developer at London Borough of Hackney (selwyn.preston@hackney.gov.uk)
• Mirela Georgieva, Lead Developer at London Borough of Hackney (mirela.georgieva@hackney.gov.uk)
• Matt Keyworth, Lead Developer at London Borough of Hackney (matthew.keyworth@hackney.gov.uk)

Other Contacts

• Rashmi Shetty, Product Owner at London Borough of Hackney (rashmi.shetty@hackney.gov.uk)