7. Appendix A: Indexing Firefox

As both a practical example and a specific reference, here is how to tweak the included container to build a DXR index of mozilla-central, the repository from which Firefox is built.

7.1. Increase Your RAM

Stop your containers, and increase the RAM and disk on your docker-machine VM (if using docker-machine). The compilation needs around 7GB. The temp files are 15GB, and the ES index and generated HTML are also on that order. It’s also a good idea to add more virtual CPUs, up to the limit of your physical ones. On your host machine...

make docker_stop
docker-machine rm default
docker-machine create --driver virtualbox --virtualbox-disk-size 80000 --virtualbox-cpu-count 4 --virtualbox-memory 8000 default

# Reset your shell variables:
eval "$(docker-machine env default)"

# And drop back into the DXR container:
make shell

7.2. Configure The Source Tree

  1. Put a mozilla-central checkout in /code on the VM. This is a special, blessed folder that will not evaporate when the docker container exits. (If you decide to put it somewhere else, be sure your choice is reflected in dxr.config in Step 4.) You can use hg clone as documented at https://developer.mozilla.org/en-US/docs/Simple_Firefox_build.


If using docker-machine and VirtualBox, keep your source code out of /home/dxr/dxr; VirtualBox’s sharing of that folder between host and guest will kill your performance.

  1. Have the compiler include the debug code so it can be analyzed. Put this in /code/mozilla-central/mozconfig:

    ac_add_options --enable-debug
    ac_add_options --disable-optimize
  2. Get it ready to build:

    cd /code/mozilla-central
    ./mach bootstrap
    ./mach mercurial-setup
  3. Put this into a new dxr.config file. It doesn’t matter where it is, but it’s a good idea to keep it outside the checkout.

    enabled_plugins=clang pygmentize
    build_command=cd $source_folder && ./mach clobber && make -f client.mk build MOZ_OBJDIR=$object_folder MOZ_MAKE_FLAGS="-s -j$jobs"

7.3. Bump Up Elasticsearch’s RAM

  1. In tooling/docker/docker-compose.yml, add an environment stanza like this:

      build: ./es
        ES_HEAP_SIZE: 2g
  2. Run make docker_es.

7.4. Kick Off The Build

Within the Docker container (remember, make shell), in the folder where you put dxr.config, run this:

dxr index

This builds your source tree and indexes it into elasticsearch. You can then run dxr serve -a to spin up the web interface against it.