Autoland is a tool that automatically lands patches from one tree to another. It also monitors test runs and re-triggers jobs automatically to help determine if failures are due to intermittents or not.

Currently Autoland is aimed at automatically landing patches from MozReview [1] to Try [2] to allow for patches to be easily pushed to Try during the review process.

A Web API is exposed to allow for try requests to be made at /autoland. This endpoint expects a json structure to be posted to it with mime-type "application/json". It is protected by HTTP Basic Auth.

The posted structure must be as follows:

{
  "tree": "mozilla-central",
  "revision": "9cc25f7ac50a",
  "destination": "try",
  "trysyntax": "try: -b o -p linux -u mochitest-1 -t none",
  "pingback_url": "http://localhost/mozreview"
}

The tree and revision specify the source of the patch to be autolanded. The destination determines where the patch will be landed. The trysyntax, which is optional, provides the additional trysyntax to be used if the destination tree is Try. The endpoint provides a callback url which is hit once the patch has been attempted to be landed.

A successful request returns a 200 and a json encoded structure containing a request_id that can be used to determine the status of the autoland request:

{
  "request_id": 42
}

A simple script which posts to this endpoint using the Python requests library can be found under testing/utils/post-job.py.

The callback json structure looks like the following:

{
  "request_id": 42,
  "tree": "mozilla-central",
  "rev": "9cc25f7ac50a",
  "destination": "try",
  "trysyntax": "try: -b o -p linux -u mochitest-1 -t none",
  "landed": true,
  "result": "1f34accb7920",
  "error_msg": ""
}

The request_id matches the request_id returned for the initial request. The tree, revision, destination and try_syntax fields match what was passed in the initial request. The landed field is true if the patch was successfully landed and false otherwise. The result field has the SHA1 of the new revision if the patch was successfully landed, otherwise, the error_msg field will contain an error message.

A status API is also provided under autoland/request/ which allows for the status of a request to be queried. The json structure returned looks like the following:

{
  "tree": "mozilla-central",
  "rev": "9cc25f7ac50a",
  "destination": "try",
  "trysyntax": "try: -b o -p linux -u mochitest-1 -t none",
  "landed": true,
  "result": "1f34accb7920"
  "error_msg": ""
}

[1] https://mozilla-version-control-tools.readthedocs.io/en/latest/mozreview.html

[2] http://hg.mozilla.org/try

Autoland consists of three components which run independently. A Flask based Web API listens for incoming autoland requests. A Pulse [1] listener listens for build started and finished messages and uses these to update test runs which are being monitored. The main autoland service periodically queries for pending autoland requests and monitored test runs which require servicing. A Postgres database is used to track autoland request and test run state.

Autoland requests are serviced by using mercurial commands to move the commit from one repository to another. If the destination repository is Try, the resulting test run will then be monitored and any failures will be retriggered exactly once as a means of dealing with intermittent failures.

[1] https://pulse.mozilla.org/

Many of the defaults here assume that Autoland is installed under /home/ubuntu/version-control-tools/autoland. You will need to adjust the configuration if this is not the case.

If not already present, install mercurial from https://www.mercurial-scm.org/downloads rather than relying upon the version present in the ubuntu packages.

Install required ubuntu packages:

sudo apt-get update
sudo apt-get install python-pip python-dev postgresql libpq-dev \
                     libldap2-dev libsasl2-dev python-virtualenv

Create and activate a virtualenv:

cd version-control-tools/autoland
virtualenv venv
. venv/bin/activate

Install python libs

pip install -r requirements.txt

Create the autoland database:

cd sql
sudo -u postgres ./createdb.sh

Install and configure Apache (optional)

sudo apt-get install apache2 libapache2-mod-wsgi
sudo a2enmod headers
sudo a2enmod wsgi
sudo rm /etc/apache2/sites-enabled/000-default.conf
sudo cp version-control-tools/apache/autoland-no-ssl.conf /etc/apache2/sites-enabled
sudo apachectl restart

Create repositories

sudo mkdir /repos
sudo chmod 777 /repos
cd /repos
hg clone https://hg.mozilla.org/mozilla-central mozreview-gecko

Add the following to the mozreview-gecko .hgrc under paths:

mozreview = http://reviewboard-hg.mozilla.org/gecko
try = ssh://hg.mozilla.org/try

User account information and other configuration is expected to be found in version-control-tools/autoland/autoland/config.json. A skeleton file used with the docker image can be found in version-control-tools/testing/docker/builder-autoland/config.json and used as a basis for creating this file.

The tests can be run by using the test script in the root version-control-tools directory:

 run-mercurial-tests -j 2 autoland/tests

Mach commands are provided by the ottoland script in the root version-control-tools directory that can be used for manual or automated tests. The implementation of the commands is in testing/vcttesting/autoland_mach_commands.py.