spurious-clojure-example

This is an example application that utilises the Spurious Clojure AWS SDK Helper.

Prerequisites

You'll need to have Spurious running (see project for installation steps).

You'll also need some content put into the Spurious S3 bucket. Here is an example script that utilises Ruby to put content into the Spurious S3 bucket (I used Ruby instead of Clojure as a way to demonstrate how Spurious works with multiple languages). Simply modify the bucket name and object path to suit your needs.

If you're not using Docker, then you'll need Leiningen 1.7.0 or above installed.

Running

Standard Web App

To start a web server for the application, run:

lein ring server

Docker

If you want to use the application from inside a Docker container you'll need to modify the application code for src/spurious_clojure_example/routes/home.clj to use :docker instead of :app.

Building the Docker image

To build the Docker image from the provided Dockerfile, execute the following command:

docker build -t spurious-clojure-example .

Note: the Dockerfile has been set-up in such a way as to cache dependencies and to only download them if they change; but I have noticed issues when testing libraries locally, so you might want to add the --no-cache flag (but be careful, you'll end up running out of disk space eventually)

Running the Docker container

Note: the --env flag is for testing purposes only
also change --publish flag to your own preference

Multi-line version (for readability)...

docker run -it --rm \
  --name spurious-app \
  --env DEBUG=true \
  --publish 4000:8080 \
  --link spurious-s3:s3.spurious.localhost \
  --link spurious-sqs:sqs.spurious.localhost \
  --link spurious-dynamo:dynamodb.spurious.localhost \
  spurious-clojure-example

One liner...

docker run -it --rm --name spurious-app --env DEBUG=true --publish 4000:8080 --link spurious-s3:s3.spurious.localhost --link spurious-sqs:sqs.spurious.localhost --link spurious-dynamo:dynamodb.spurious.localhost spurious-clojure-example

Testing the Docker container

I wanted to test the spurious-clojure-aws-sdk-helper before releasing it officially to the public Clojars repository.

To do this I ran lein install from that code repo - which installs it locally to your ~/.m2 cache. Now I'm able to add this cache directory into my Docker container to use instead of the actual Clojars endpoint. To do this follow these steps:

Add ADD .m2/repository /root/.m2/repository to the Dockerfile
Run rm -rf .m2 to remove the directory from this current repo (in case you followed these steps previously)
Run cp -r ~/.m2 ./ (to get a fresh copy of your lein cache into this repo)
Run docker build -t spurious-clojure-example . to build a new image with the fresh cache
Run the container as before

Messing around with the official Clojure Docker image

It can be useful to jump inside a running Clojure based Docker container by using the following command. For example, I needed to verify the location of the lein cache directory within a non-mac environment):

docker run -it -v /path/to/your/app:/app clojure bash

Notes

The following notes all refer to the spurious-clojure-example.routes.home namespace...

You'll notice that the helper is loaded within the ns macros rather than dynamically loaded at runtime. This is because the application (when deployed) is compiled into a Jar file with all dependences included; this means that there is no point doing a dynamic require of a library when in dev/debug mode.
There are two keynames :bucket-name and :key (which is an S3 object path). Make sure to set the values to an appropriate location which matches your own (Spurious/Live) S3 objects.
The credentials function is only to demonstrate the principle of using a basic if condition to switch between dev/debug and live credentials. Obviously (well, it probably should be obvious) storing your access keys in your code is a bad idea and they should be referenced via some external mechanism (such as environment variables).

Integralist/spurious-clojure-example