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This repository contains a Dockerized version of the Pact Broker. You can pull the pactfoundation/pact-broker image from Dockerhub. If you're viewing these docs on Dockerhub, here is a link to the github repository.

Note: On 12 May 2018, the format of the docker tag changed from M.m.p-RELEASE to M.m.p.RELEASE (where M.m.p is the semantic version of the underlying Pact Broker package) so that Dependabot can recognise when the version has been incremented.

In a hurry?

If you want to try out a Pact Broker that can be accessed by all your teams, without having to fill in requisition forms and wait for 3 months, you can get a free trial at Built by a group of core Pact maintainers, Pactflow is a fork of the OSS Pact Broker with extra goodies like an improved UI, field level verification results and federated login. It's also fully supported, and that means when something goes wrong, someone else gets woken up in the middle of the afternoon to fix it...

Migrating from the dius/pact-broker image

The pactfoundation/pact-broker image is a forked version of the dius/pact-broker image. It is smaller (as it runs on Alpine Linux with Puma instead of the larger Passenger Phusion base image), and does not need root permissions.

All the environment variables used for dius/pact-broker are compatible with pactfoundation/pact-broker. The only breaking change is that the default port has changed from 80 to 9292 (because a user without root permisisons cannot bind to a port under 1024). If you wish to expose port 80 (or 443) you can deploy Ngnix in front of it (see the docker-compose file for an example).

Which one should I use?

Please read for information on which server will suit your needs best. The tl;dr is that if you want to run the docker image in a managed architecture which will make your application highly available (eg. ECS, Kubernetes) then use the pactfoundation/pact-broker. Puma will not restart itself if it crashes, so you will need external monitoring to ensure the Pact Broker stays available.

If you want to run the container as a standalone instance, then the dius/pact-broker image which uses Phusion Passenger may serve you better, as Passenger will restart any crashed processes.


  • A running Postgresql (or MySQL) database and the ability to connect to it (see Postgres is recommended over MySQL for performance and support reasons.

Getting Started

  1. Install Docker
  2. Prepare your environment if you are not running postgresql in a docker container. Setup the pact broker connection to the database through the use of the following environment variables.

For a postgres or mysql database:

You can either set the PACT_BROKER_DATABASE_URL in the format driver://username:password@host:port/database (eg. postgres://user1:pass1@myhost/mydb) or, you can set the credentials individually using the following environment variables:

* `PACT_BROKER_DATABASE_ADAPTER` (optional, defaults to 'postgres', see note below.)
* `PACT_BROKER_DATABASE_PORT` (optional, defaults to the default port for the specified adapter)

Adapter can be 'postgres' (recommended) or 'mysql2'. It is strongly recommended that you use Postgres rather than MySQL if possible as the SQL queries are optimised for Postgres. You may run into performance issues due to the size of the database sooner on MySQL than Postgres.

For an sqlite database (only recommended for investigation/spikes, as it will be disposed of with the container unless you mount it from an external file system):

  • PACT_BROKER_DATABASE_ADAPTER (set to 'sqlite')
  • PACT_BROKER_DATABASE_NAME (arbitrary name eg. pact_broker.sqlite)

You can additionally set:

* `PACT_BROKER_DATABASE_SSLMODE` - optional, possible values: 'disable', 'allow', 'prefer', 'require', 'verify-ca', or 'verify-full' to choose how to treat SSL (only respected if using the postgres database adapter. See for more information.)
* `PACT_BROKER_SQL_LOG_LEVEL` - optional, defaults to debug. The level at which to log SQL statements.
* `PACT_BROKER_SQL_LOG_WARN_DURATION` - optional, defaults to 5 seconds. Log the SQL for queries that take longer than this number of seconds.
* `PACT_BROKER_DATABASE_MAX_CONNECTIONS` - optional, defaults to 4. The maximum size of the connection pool. There is no need to set this unless you notice particular connection contention issues.
* `PACT_BROKER_DATABASE_POOL_TIMEOUT` - optional, 5 seconds by default. The number of seconds to wait if a connection cannot be acquired before raising an error. There is no need to set this unless you notice particular connection contention issues.


  • The application makes use of the Puma application server.
  • Apart from creating a database no further preparation is required.

Using basic auth

To enable basic auth, run your container with:


If you want to allow public read access (but still require credentials for writing), then omit setting the READ_ONLY credentials and set PACT_BROKER_ALLOW_PUBLIC_READ=true.

Developers should use the read only credentials on their local machines, and the CI should use the read/write credentials. This will ensure that pacts and verification results are only published from your CI.

Note that the verification status badges are not protected by basic auth, so that you may embed them in README markdown.

Heartbeat URL

If you are using the docker container within an AWS autoscaling group, and you need to make a heartbeat URL publicly available, set PACT_BROKER_PUBLIC_HEARTBEAT=true. No database connection will be made during the execution of this endpoint.

The heartbeat is available at /diagnostic/status/heartbeat.

Using SSL

See the Pact Broker configuration documentation.

Setting the log level

Set the environment variable PACT_BROKER_LOG_LEVEL to one of DEBUG, INFO, WARN, ERROR, or FATAL.

Webhook whitelists

  • PACT_BROKER_WEBHOOK_HOST_WHITELIST - a space delimited list of hosts (eg., network ranges (eg., or regular expressions (eg. /.*\\.foo\\.com$/). Regular expressions should start and end with a / to differentiate them from Strings. Note that backslashes need to be escaped with a second backslash. Please read the Webhook whitelists section of the Pact Broker configuration documentation to understand how the whitelist is used. Remember to use quotes around this value as it may have spaces in it.
  • PACT_BROKER_WEBHOOK_SCHEME_WHITELIST - a space delimited list (eg. http https). Defaults to https.

Other environment variables

  • PACT_BROKER_PORT - the port that the Pact Broker application runs on. Defaults to 9292.
  • PACT_BROKER_BASE_URL - optional. If you find that the URLs generated by the API are using an IP instead of a hostname, you can set this environment variable to force the desired base URL. Must include the port if it's a non-standard one. eg. https://my-broker:9292. This can also be used if you are mounting the Docker container so that it runs on a non root context eg. Not that this setting does not change where the application is mounted within the Docker container - it just changes the links.
  • PACT_BROKER_DISABLE_SSL_VERIFICATION - false by default, may be set to true.
  • PACT_BROKER_ORDER_VERSIONS_BY_DATE - true by default. Setting this to false is deprecated.
  • PACT_BROKER_PUMA_PERSISTENT_TIMEOUT - allows configuration of the Puma persistent timeout.

General Pact Broker configuration and usage

Documentation for the Pact Broker application itself can be found in the Pact Broker docs.

Running with Docker Compose

For a quick start with the Pact Broker and Postgres, we have an example Docker Compose setup you can use:

  1. Modify the docker-compose.yml file as required.
  2. Run docker-compose build to build the pact_broker container locally.
  3. Run docker-compose up to get a running Pact Broker and a clean Postgres database.

Now you can access your local broker:

curl -v http://localhost # you can visit in your browser too!
# SSL endpoint, note that URLs in response contain https:// protocol
curl -v -k https://localhost:8443

NOTE: this image should be modified before using in Production, in particular, the use of hard-coded credentials

Running with Openshift

If you call your service "pact_broker", an environment variable called PACT_BROKER_PORT will be created which will conflict with the Docker image's PACT_BROKER_PORT (see this issue for background). In this case, you have two options.

See pact-broker-openshift for an example config file.

Running on Kubernetes

If you call your service "pact_broker", an environment variable called PACT_BROKER_PORT will be created which will conflict with the Docker image's PACT_BROKER_PORT (see this issue for background). In this case, you have two options.

Running on Heroku

Heroku provides the database connection string as the environment variable DATABASE_URL, and the port as PORT. See the section on Using different environment variable names to allow the Pact Broker to use these environment variables instead of PACT_BROKER_PORT and PACT_BROKER_DATABASE_URL.

Running on AWS with an ALB

If you are running the Docker image behind an ALB with an idle timeout, you may need to set the Puma persistent timeout using the PACT_BROKER_PUMA_PERSISTENT_TIMEOUT environment variable. See issue 26 for details.

You will also want to make use of the Heartbeat URL

Using different environment variable names

If you are running your Docker container in a managed environment, you may not be able to control the names of the environment variables that are set by that software.

In this case, you can tell the application to use different environment variables to source the following configuration options.


To allow the port of the Pact Broker to be set by a different environment variable, set PACT_BROKER_PORT_ENVIRONMENT_VARIABLE_NAME to the name of your chosen variable, and then set that variable. eg.


Database URL

To allow the URL of the database to be set by a different environment variable, set PACT_BROKER_DATABASE_URL_ENVIRONMENT_VARIABLE_NAME to the name of your chosen variable, and then set that variable. eg.


Database migrations

The Pact Broker auto migrates on startup, and will always do so in a way that is backwards compatible, to support architectures that run multiple instances of the application at a time (eg. AWS auto scaling).

From the /pact_broker directory on the docker image, you can run migration and rollback scripts via rake. A rollback would be required if you needed to downgrade your Pact Broker image.

To work out which migration to rollback to, select the tag of the Pact Broker gem version you want at and then look in the db/migrations directory. Find the very last migration in the directory, and take the numbers at the start of the file name. This is your "target".

To rollback run:

bundle exec rake pact_broker:db:migrate[target] eg bundle exec rake pact_broker:db:migrate[20191101]

You can confirm the new version by running bundle exec rake pact_broker:db:version


See the Troubleshooting page on the docs site.

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