A very simple media content service, built on Spring Boot. Provides a quick and easy way to manage the storage, upload and access to media and assets, in a situation where a real CDN may not (yet) be a viable solution.
Contessa is packaged as a fat-jar, and can be started by simply running it. The
minimal required configuration is to set the base-dir property, which is
required, and starting won't be possible without it.
$ java -Dcontessa.base-dir=data/ -jar contessa.jar
You can now browse http://localhost:8080 and you should see some application
information.
There are two main user interfaces on top of HTTP; a straight-forward web, and
a REST-ful API mapped to http://localhost:8080/api/v1. The REST-ful API does
not serve the actual content, but rather provides content entries as
application/json resources.
All content entry data is served from the web UI.
Users will typically upload some named content, and capture the response, which will be the unique content entry URI.
$ curl --request POST \
--header "content-type: application/octet-stream" \
--data-binary "@some.gif" \
http://localhost:8080/some.gif
http://localhost:8080/ede542cb-f8ec1d4.gif
The returned URI is calculated to be unique, both with regards to the data as well as the name.
If we request the URI we can see that Contessa will return a cache-control
header, which by default uses a max-age of 100 days.
$ curl -I http://localhost:8080/ede542cb-f8ec1d4.gif
HTTP/1.1 200
ETag: "ede542cb-f8ec1d4"
Cache-Control: max-age=8640000, public
Content-Type: image/gif
Content-Length: 27566
Date: Sun, 14 Jan 2018 21:15:48 GMT
Submitting some content to the REST-ful interface, also requires the user to
POST some content with a specified name.
$ curl --request POST \
--header "content-type: application/octet-stream" \
--data-binary "@some.gif" \
http://localhost:8080/api/v1/some.gif
{
"identifier" : "ede542cb-f8ec1d4",
"length" : 27566,
"type" : "image/gif",
"suffix" : "gif",
"uri" : "http://localhost:8080/ede542cb-f8ec1d4.gif"
}
The response is a small JSON object, which provides the user with information about the content entry.
Content entry resources can also be queried on the REST-ful API, by using the
identifier.
$ curl http://localhost:8080/api/v1/ede542cb-f8ec1d4
{
"identifier" : "ede542cb-f8ec1d4",
"length" : 27566,
"type" : "image/gif",
"suffix" : "gif",
"uri" : "http://localhost:8080/ede542cb-f8ec1d4.gif"
}
The content entry resource property uri can then be used to access the actual
data.
Directly under the Contessa base-dir, the folder dropbox is created, in
order to provide support to manually add content.
By giving users access to this directory, they may drop in content files and
have Contessa repond with information about the added entry. We start Contessa
with the property -Dcontessa.base-dir=data/.
$ ls -la data/dropbox/
.
..
$ cp some.gif data/dropbox/
$ ls -la data/dropbox/
.
..
some.gif
(some seconds later)
$ ls -la data/dropbox/
.
..
some.gif___ede542cb-f8ec1d4.gif
The dropped file will be picked up by Contessa and handled. The response is then written back as a marker-file, which the user must take care of, and clean out manually. Any response marker-files will of course be ignored by Contessa.
If Contessa is started and the contessa.amqp.enabled=true property is set, it
will start and connect to a RabbitMQ.
To add content entries over the message broker we need to publish a message with
the upload routing key, naming the file with the header filename. We provide
a reply_to for the response and add the content to the message body.
In the overview we now see that our queue me has received one message.
The response returned contains header fields with identifier, suffix and
the media type. The body payload consists of the created media entity name.
In this small example we can now query the media over HTTP, either using the web or REST endpoints.
The main intent is to have a simple content service, with a strict and minimal API surface. Users should be able to submit and retrieve, content files in some appropriate ways.
Contessa will provide a very rich configurable out-of-the-box solution, that offers a sensible and adaptive solution to business hosting of media content.
The design goal is to provide a separation between the two most important sub-systems or tiers - the user interface or API and the storage backend or data repository.
Using a simple set of configurations, the storage of data can be controlled, and easily set up for local filestorage, SQL or NoSQL storage.
Each storage comes with a different set of capabilities and Contessa allows for an adaptable solution, that suites many different business goals.
Accessing or uploading data can be made in several different ways. From plain HTTP or web to REST-ful APIs, file-system polling or message bus brokers, the feature-set is rich and very capable. This puts Contessa in a compatibility level of its own.
The current aim and goal of Contessa is to ensure the best possible capabilities for a meda content storage - but also, to stay within the boundaries of a very well understood and capable technical stack.
Building on Java and Spring Boot, currently mean that we can leverage the knowledge and interest of a whole lof of developers. We believe these developers to also be great ambassadors for Contessa, if we can provide them with idiomatic, transparent and well thought out code.
Anyone should be able to join in, and as the project evolves we will provide
more specific information. At the moment running the project should be as easy
as starting the project using the shortcut in the Makefile:
> make start
There will be more documentation evolving inside the docs/ folder.
Happy hacking!