Gaffer Images

As demonstrated in the quickstart it is very simple to start up a basic in memory Gaffer graph using the available Open Container Initiative (OCI) images.

For large scale graphs with persistent storage you will want to use a different storage backend to a Map Store; the recommended one being Accumulo. To do this a different deployment of containers are required. This guide will run through the containers needed for a basic Accumulo cluster and how to configure and create custom images of Gaffer.

Available Images

Currently there are a few different images that can be used to run a Gaffer deployment. The main ones are outlined in the following table and are all available on Docker Hub.

Image	Description
`gchq/accumulo`	This image is a containerised deployment of Apache Accumulo. This was created as historically there has not been an available official image from the maintainers of Accumulo. There has since been an offical image made available however, it is not well supported so not currently in use in Gaffer.
`gchq/hdfs`	A custom image for running HDFS (Hadoop file system) via a container. Contains an official release of Apache Hadoop which is used as the scalable data storage for Accumulo.
`gchq/gaffer`	This is the main container image for Gaffer that is built on on top of the `gchq/accumulo` image so includes a release of `zookeeper`, `hdfs` and `accumulo` along with the Gaffer libraries. Running this image simply runs an Accumulo instance but with the Gaffer libraries loaded to allow Graph creation.
`gchq/gaffer-rest`	This is the REST API image containing the files that can be used to configure the graph to connect to the chosen store, by default there are some pre-configured config files which can be overridden by a bind-mount of alternatives.

Note

There are a few other images available; however, they are less frequently used or purely example images, please see the gaffer-docker repository for more details.

Volumes and bind-mount

To change and configure the graph that is deployed you will need to override the default files in the images by default. You can of course create a custom image with different config files however, it can be more flexible to just bind-mount over the current files.

To do this you will need to know the location of the files in the image you want to override but in many cases you can mount over an entire directory for example:

The path /custom/configs is some path on the host system with different config files in that can be mounted in when running the image.

docker run \
       -p 8080:8080 \
       -v /custom/configs/gaffer/graph:/gaffer/graph \
       -v /custom/configs/gaffer/schema:/gaffer/schema \
       -v /custom/configs/gaffer/store:/gaffer/store \
       gchq/gaffer-rest:2.0.0

Custom Images

To avoid managing a file on the host and bind-mount it, the configuration can be baked into the image. This works well if the configuration itself is rather static and the same across all environments.

Creating a custom image can also be useful if you want to load custom extensions to use with Gaffer (e.g. Jars) by default.

To create a custom image simply make a new Dockerfile and use one of the Gaffer images as the base image like the following:

FROM gchq/gaffer-rest:latest

# Copy over the existing directory with store configs in
COPY ./custom/configs/gaffer/store /gaffer/store

Then build the new image using a suitable tool or just plain Docker from the current directory like:

docker build -t my-gaffer-rest .

Adding Additional Libraries

By default with the Gaffer deployment you get access to the:

Sketches library
Time library
Bitmap Library
JCS cache library

If you want more libraries than this (either one of ours of one of your own) you will need to customise the docker images and use them in place of the defaults.

At the moment, the gchq/gaffer-rest image uses a runnable jar file located at /gaffer/jars. When it runs it includes the /gaffer/jars/lib on the classpath. This is empty by default because all the dependencies are bundled in to the JAR. However, if you wanted to add your own jars, you can add then to this directory like the following:

FROM gchq/gaffer-rest:latest
COPY ./custom-lib:1.0-SNAPSHOT.jar /gaffer/jars/lib/

For an Accumulo deployment, you may wish to add additional libraries to the classpath to enable the use of new iterators. To do this you need to update the gchq/gaffer image and add the JARs to the /opt/accumulo/lib/ext directory:

FROM gchq/gaffer:latest
COPY ./my-library-1.0-SNAPSHOT.jar /opt/accumulo/lib/ext

Note

This path is different in Accumulo v1 please see the migration page for more detail.