Digital Preservation

Services related to Digital Preservation for University of Leeds DLIP project.

Projects

There are a number of entry points (ie runnable) projects and various shared projects these applications use.

Entry Points

• Storage.API - wrapper on top of underlying Fedora storage.
• Preservation.API - higher level Preservation API consuming Storage API.
• DigitalPreservation.UI - user interface for interacting with above services.

Shared

• DigitalPreservation.Core - various common helper functions.
• Storage.Client - HTTP client for Storage API.
• Preservation.Client - HTTP client for Preservation API.

Technology 🤖

Projects written in .net8 using libraries including:

• Serilog - structured logging framework.
• Mediatr - mediator implementation for in-proc messaging.
• XUnit - automated test framework.

Getting Started

Each entry point has a Dockerfile. There is a docker compose file available for ease of running services. Rename .env.dist to .env as a starting point for configuration.

# build images
docker compose build

# run images
docker compose up

For local development docker-compose.local.yml can be used to run any dependencies (e.g. Postgres)

docker compose -f docker-compose.local.yml  up

You also need to read Fedora's PostgreSQL database through the bastion host; this should use port 5435

Migrations

Migrations can be added by running the following:

cd src/DigitalPreservation

dotnet ef migrations add "<migration-name>" -p Preservation.API -o Data/Migrations

Deployments

Github actions are used for deployments.

The overall process is:

• dotnet test to confirm build + tests passing
• build and push Docker images to ECR, tagged with current branch/sha1
• push to environment, which consists of:
  • pulling docker image from ECR
  • retag image with environment-specific tag and push to ECR (images deployed with mutable tags)
  • restart ECS service to pull down latest image

Builds kicked off by:

• Create PR (non-draft) - push to development
  • Push can be avoided if PR has "no-deploy" label
• Push to main - push to development and production
• Create version tag - push to production
• Manual running action

Note

Only development environment currently exists. Builds will need expanded when we have further environments.