Buildbot server configuration

Hosts

The buildbot server is hosted on krbdev-buildbot.mit.edu. Workers are listed in machines.txt in the krbdev-services repository.

Packages

Only the buildbot package is required.

Master setup

buildbot 0.9 changes its terminology to refer to "workers" rather than "slaves". At the current time the buildbot server runs on Ubuntu 16.04, where the buildbot package is version 0.8.12. These notes will need to be updated when we move to 0.9 or later.

Run:

 su -s /bin/bash - buildbot
 touch .k5login
 rmdir masters slaves
 buildbot create-master -r master

Install buildbot/master.cfg from krbdev-services into /var/lib/buildbot/master. Copy /var/lib/buildbot/master/slaves.py from the old server. Make sure both files are owned by and readable by buildbot. If it is necessary to reconstruct slaves.py, has the form:

 from buildbot.buildslave import BuildSlave
 slaves = [
     BuildSlave('v09', '<password>', properties={'platform': 'amd64-u1204'}),
     ...
 ]

The name and password must match the values used on the worker. The platform is mostly arbitrary and will be used to construct builder entries. Multiple workers can have the same platform. The third argument may be omitted for workers which run special tasks (such as the documentation build) which aren't part of the regular platform builds.

Copy over .ssh/authorized_keys from the old server's /var/lib/buildbot. If it is necessary to reconstruct it, it must contain the ssh key for each worker entry (.ssh/id_rsa.pub from the buildbot account on the worker).

As root, edit /etc/default/buildmaster and change the values so they read:

 MASTER_ENABLED[1]=1
 MASTER_NAME[1]="master"
 MASTER_USER[1]="buildbot"
 MASTER_BASEDIR[1]="/var/lib/buildbot/master"
 MASTER_OPTIONS[1]=""
 MASTER_PREFIXCMD[1]=""

Run "service buildmaster restart".

Worker setup

For the Solaris buildbot worker, see Solaris_Build_Environment for platform-specific instructions.

Install the buildbot slave software, using the buildbot-slave package or the platform equivalent.

If the platform package does not create a buildbot account, create one with a home directory. Make sure it has an empty .k5login file, or one containing developer principals. These instructions will assume that the buildbot home directory is /var/lib/buildbot.

As the buildbot account ("su -s /bin/bash - buildbot"), generate a key using:

 ssh-keygen -q -N  -f .ssh/id_rsa -t rsa

Add the contents of .ssh/id_rsa.pub to .ssh/authorized_keys on krbdev-buildbot.mit.edu.

Run "ssh -l buildbot krbdev-buildbot.mit.edu" to get the master host key into .ssh/known_hosts. The correct host key fingerprint of the master can be obtained by running "ssh-keygen -l -E md5 -f /etc/ssh/ssh_host_ecdsa_key.pub" on krbdev-buildbot.mit.edu (or perhaps ssh_host_rsa_key.pub or ssh_host_dsa_key.pub if the worker has an old ssh client).

Create a "slaves" directory in buildbot's home directory and run "buildslave create-slave /var/lib/buildbot/slaves/NAME 127.0.0.1:9989 NAME PASSWORD", using the name and password from the slaves.py entry for the worker.

Arrange for the buildslave process to be started on boot. On Ubuntu, this is accomplished by editing /etc/default/buildslave and setting:

 SLAVE_ENABLED[1]=1
 SLAVE_NAME[1]="NAME"
 SLAVE_USER[1]="buildbot"
 SLAVE_BASEDIR[1]="/var/lib/buildbot/slaves/NAME"
 SLAVE_OPTIONS[1]=""
 SLAVE_PREFIXCMD[1]=""

Add a cron job for the buildbot account (run "crontab -e" as buildbot) to maintain the ssh tunnel to the master:

 */5 *  *   *   *     exec ssh -oExitOnForwardFailure=yes -l buildbot -N -L9989:127.0.0.1:9989 krbdev-buildbot.mit.edu