Kaleidoscope

Kaleidoscope is a content management system for blogging.

This repository is the backend. It contains:

• Backend: Clojure web server that uses Virtual Hosting to serve two different apps: a blog (andrewslai), and a photo viewer app
• Infrastructure: Terraform for AWS cloud infrastructure

Architecture of the Clojure namespaces

Figure 1. A high level view of the architecture of the Clojure namespaces in the app.

1. At start time, the main namespace uses the init.config namespace to parse environment variables and creates components to inject into the app
2. init.config starts components

System Components

1. :virtual-hosting: Allows you to direct multiple URLs to a single JVM and serve multiple websites/apps from a single instance of the app. Used to serve separate apps on andrewslai.com and caheriaguilar.and.andrewslai.com (Route53 points both domains to the same load balancer, and when requests hit the ECS app, :virtual-hosting is used to serve different apps on different domains).
2. :persistence.rdbms: An RDBMS is used as a persistent data store. Depending on environment variables, the app could connect to a live Postgres instance that is accessible via the network, or could start an embedded DB (H2 or Postgres) for testing.
3. :persistence.filesystem: The app serves static files from a Filesystem. For the wedding app, a Filesystem used to store pictures and media. Both apps serve index.html and associated Javascript from a Filesystem (S3). Can be set to an S3 implementation, or an in-memory filesystem for testing.
4. :http-api.middleware: Multiple stacks of middleware are defined here and can be composed together or used to configure how a given Ring handler behaves. a. (Static-Content middleware): If static content middleware is enabled, the app will serve static content from the :persistence.filesystem implementation - i.e. a request to /media/foo.svg would try to look up the content located at path /media/foo.svg in the :persistence.filesystem. In a live implementation, this is basically a thin wrapper that serves static content in an S3 bucket via the Ring handler.
5. :http.auth: Resources in the HTTP API should be protected against unwanted access. This component is used to configure how users Authenticate over HTTP. Can use different buddy backends - some that check HTTP request headers for appropriate tokens, and others that accept everyone as authenticated (for testing). The normal live implementation is a Keycloak backend, which takes Authorization Bearer tokens in the HTTP header, parses them, and reaches out to a live Keycloak server/IDP over the network to verify the user's identity.

Additional configuration

1. init.config HTTP Access rules: Can be set at run time to protect http routes behind role-based access criteria. Used to determine which user scopes are able to access specific resources on the server

Installation/setup

Clone the repo and install leiningen.

Tests

lein test

Build: Uberjar

lein do clean, uberjar

Build: Docker

lein do clean, uberjar
docker build -t kaleidoscope .

Run without Docker

lein run

Run with Docker

After docker build and setting up .env.docker.local with correct environment

docker run --env-file=.env.docker.local -p 5000:5000 kaleidoscope

To serve a local copy of the Andrewslai frontend, mount a volume to the Docker container.

docker run --env-file=.env.docker.local \
            -p 5000:5000 \
            -v /Users/alai/spl/andrewslai-frontend/resources/public:/andrewslai-frontend/resources/public \
            kaleidoscope

Development

For local development, see local-development.md

Deployment

To deploy, follow instructions in deployment.md