Upgrade or modify Zulip

This page explains how to upgrade, patch, or modify Zulip, including:

Upgrading to a release

Note that there are additional instructions if you're using docker-zulip, have patched Zulip, or have modified Zulip-managed configuration files. To upgrade to a new Zulip release:

  1. Read the upgrade notes for all releases newer than what is currently installed.

  2. Download the appropriate release tarball from https://download.zulip.com/server/ You can download the latest release with:

    bash curl -fLO https://download.zulip.com/server/zulip-server-latest.tar.gz

    You also have the option of upgrading Zulip to a version in a Git repository directly or creating your own release tarballs from a copy of the zulip.git repository using tools/build-release-tarball.

  3. Log in to your Zulip and run as root:

    bash /home/zulip/deployments/current/scripts/upgrade-zulip zulip-server-VERSION.tar.gz

    The upgrade process will: * Run apt-get upgrade * Install new versions of Zulip's dependencies (mainly Python packages). * (upgrade-zulip-from-git only) Build Zulip's frontend assets using webpack. * Shut down the Zulip service * Run a puppet apply * Run any database migrations * Bring the Zulip service back up on the new version.

Upgrading will result in brief downtime for the service, which should be under 30 seconds unless there is an expensive database migration involved (these will be documented in the release notes, and usually can be avoided with some care). If downtime is problematic for your organization, consider testing the upgrade on a backup in advance, doing the final upgrade at off hours, or buying a support contract.

See the troubleshooting guide if you run into any issues or need to roll back the upgrade.

Upgrading from a Git repository

Zulip supports upgrading a production installation to any commit in a Git repository, which is great for running pre-release changes from master or maintaining a fork. The process is simple:

# Upgrade to an official release
/home/zulip/deployments/current/scripts/upgrade-zulip-from-git 1.8.1
# Upgrade to a branch (or other Git ref)
/home/zulip/deployments/current/scripts/upgrade-zulip-from-git 2.1.x
/home/zulip/deployments/current/scripts/upgrade-zulip-from-git master

Zulip will automatically fetch the relevant Git commit and upgrade to that version of Zulip.

Branches with names like 2.1.x are stable release branches, containing the changes planned for the next minor release (E.g. 2.1.5); we support these stable release branches as though they were a published release.

The master branch contains changes planned for the next major release (E.g. 3.0); see our documentation on running master before upgrading to it.

By default, this uses the main upstream Zulip server repository, but you can configure any other Git repository by adding a section like this to /etc/zulip/zulip.conf:

[deployment]
git_repo_url = https://github.com/zulip/zulip.git

See also our documentation on upgrading docker-zulip.

Updating settings.py inline documentation

Zulip installations often upgrade many times over their lifetime, and we strive to keep all configuration files backwards-compatible. However, our practice of leaving the /etc/zulip/settings.py unchanged during upgrades means that there may be new features which are not documented in that file, since it was based on a template provided by an earlier version of Zulip, during the initial install.

After upgrading across major versions of Zulip Server, we recommend comparing your /etc/zulip/settings.py file to the current settings template, which can be found in /home/zulip/deployments/current/zproject/prod_settings_template.py. We suggest using that updated template to update /etc/zulip/settings.py:

  1. Copy the current settings.py to make a backup (especially if you do not have a recent complete backup), and make a copy of the current template:

bash cp -a /etc/zulip/settings.py ~/zulip-settings-backup.py cp -a /home/zulip/deployments/current/zproject/prod_settings_template.py /etc/zulip/settings-new.py

  1. Open both /etc/zulip/settings.py and /etc/zulip/settings-new.py files in an editor; for each setting set in settings.py, find its section in /etc/zulip/settings-new.py and copy the setting from settings.py into there.

The following tool may help, by finding the most likely version of the template that your /etc/zulip/settings.py was installed using, and the differences that your file has from that:

bash /home/zulip/deployments/current/scripts/setup/compare-settings-to-template

If there are settings which you cannot find documented in /etc/zulip/settings-new.py, check the changelog to see if they have been removed.

  1. Overwriting the configuration with the updated file, and restart the server to pick up the new file; this should be a no-op, but it is much better to discover immediately if it is not:

bash cp -a /etc/zulip/settings-new.py /etc/zulip/settings.py su zulip -c '/home/zulip/deployments/current/scripts/restart-server'

Troubleshooting and rollback

See also the general Zulip server troubleshooting guide.

The upgrade scripts are idempotent, so there's no harm in trying again after resolving an issue. The most common causes of errors are:

Useful logs are available in a few places: * The Zulip upgrade scripts log all output to /var/log/zulip/upgrade.log. * The Zulip server logs all Internal Server Errors to /var/log/zulip/errors.log.

If you need help and don't have a support contract, you can visit #production help in the Zulip development community server for best-effort help. Please include the relevant error output from the above logs in a Markdown code block in any reports.

Rolling back to a prior version

This rollback process is intended for minor releases (e.g. 2.0.3 to 2.0.6); a more complicated process is required to roll back database migrations before downgrading to an older major release.

The Zulip upgrade process works by creating a new deployment under /home/zulip/deployments/ containing a complete copy of the Zulip server code, and then moving the symlinks at /home/zulip/deployments/{current,last,next} as part of the upgrade process.

This means that if the new version isn't working, you can quickly downgrade to the old version by running /home/zulip/deployments/last/scripts/restart-server, or to an earlier previous version by running /home/zulip/deployments/DATE/scripts/restart-server. The restart-server script stops any running Zulip server, and starts the version corresponding to the restart-server path you call.

Preserving local changes to service configuration files

:::{warning} If you have modified service configuration files installed by Zulip (e.g. the nginx configuration), the Zulip upgrade process will overwrite your configuration when it does the puppet apply. :::

You can test whether this will happen assuming no upstream changes to the configuration using scripts/zulip-puppet-apply (without the -f option), which will do a test Puppet run and output and changes it would make. Using this list, you can save a copy of any files that you've modified, do the upgrade, and then restore your configuration.

That said, Zulip's configuration files are designed to be flexible enough for a wide range of installations, from a small self-hosted system to Zulip Cloud. Before making local changes to a configuration file, first check whether there's an option supported by /etc/zulip/zulip.conf for the customization you need. And if you need to make local modifications, please report the issue so that we can make the Zulip Puppet configuration flexible enough to handle your setup.

nginx configuration changes

If you need to modify Zulip's nginx configuration, we recommend first attempting to add configuration to /etc/nginx/conf.d or /etc/nginx/zulip-include/app.d; those directories are designed for custom configuration.

Upgrading the operating system

When you upgrade the operating system on which Zulip is installed (E.g. Ubuntu 18.04 Bionic to Ubuntu 20.04 Focal), you need to take some additional steps to update your Zulip installation, documented below.

The steps are largely the same for the various OS upgrades aside from the versions of PostgreSQL, so you should be able to adapt these instructions for other supported platforms.

Upgrading from Ubuntu 18.04 Bionic to 20.04 Focal

  1. Upgrade your server to the latest Zulip release (at least 3.0, which adds support for Ubuntu Focal).

  2. As the Zulip user, stop the Zulip server and run the following to back up the system:

    bash supervisorctl stop all /home/zulip/deployments/current/manage.py backup --output=/home/zulip/release-upgrade.backup.tar.gz

  3. Switch to the root user and upgrade the operating system using the OS's standard tooling. E.g. for Ubuntu, this means running do-release-upgrade and following the prompts until it completes successfully:

    bash sudo -i # Or otherwise get a root shell do-release-upgrade

    When do-release-upgrade asks you how to upgrade configuration files for services that Zulip manages like Redis, PostgreSQL, Nginx, and memcached, the best choice is N to keep the currently installed version. But it's not important; the next step will re-install Zulip's configuration in any case.

  4. As root, upgrade the database to the latest version of PostgreSQL:

    bash /home/zulip/deployments/current/scripts/setup/upgrade-postgresql

  5. Ubuntu 20.04 has a different version of the low-level glibc library, which affects how PostgreSQL orders text data (known as "collations"); this corrupts database indexes that rely on collations. Regenerate the affected indexes by running:

bash /home/zulip/deployments/current/scripts/setup/reindex-textual-data --force

  1. Finally, we need to reinstall the current version of Zulip, which among other things will recompile Zulip's Python module dependencies for your new version of Python and rewrite Zulip's full-text search indexes to work with the upgraded dictionary packages:

    bash rm -rf /srv/zulip-venv-cache/* /home/zulip/deployments/current/scripts/lib/upgrade-zulip-stage-2 \ /home/zulip/deployments/current/ --ignore-static-assets --audit-fts-indexes

This will finish by restarting your Zulip server; you should now be able to navigate to its URL and confirm everything is working correctly.

Upgrading from Ubuntu 16.04 Xenial to 18.04 Bionic

  1. Upgrade your server to the latest Zulip 2.1.x release. You can only upgrade to Zulip 3.0 and newer after completing this process, since newer releases don't support Ubuntu 16.04 Xenial.

  2. Same as for Bionic to Focal.

  3. Same as for Bionic to Focal.

  4. As root, upgrade the database installation and OS configuration to match the new OS version:

    bash touch /usr/share/postgresql/10/pgroonga_setup.sql.applied /home/zulip/deployments/current/scripts/zulip-puppet-apply -f pg_dropcluster 10 main --stop systemctl stop postgresql pg_upgradecluster 9.5 main pg_dropcluster 9.5 main apt remove postgresql-9.5 systemctl start postgresql systemctl restart memcached

  5. Finally, we need to reinstall the current version of Zulip, which among other things will recompile Zulip's Python module dependencies for your new version of Python:

    bash rm -rf /srv/zulip-venv-cache/* /home/zulip/deployments/current/scripts/lib/upgrade-zulip-stage-2 \ /home/zulip/deployments/current/ --ignore-static-assets

This will finish by restarting your Zulip server; you should now be able to navigate to its URL and confirm everything is working correctly.

  1. Upgrade to the latest Zulip release, now that your server is running a supported operating system.

  2. As root, finish by verifying the contents of the full-text indexes:

    bash /home/zulip/deployments/current/manage.py audit_fts_indexes

Upgrading from Ubuntu 14.04 Trusty to 16.04 Xenial

  1. Upgrade your server to the latest Zulip 2.0.x release. You can only upgrade to Zulip 2.1.x and newer after completing this process, since newer releases don't support Ubuntu 14.04 Trusty.

  2. Same as for Bionic to Focal.

  3. Same as for Bionic to Focal.

  4. As root, upgrade the database installation and OS configuration to match the new OS version:

    bash apt remove upstart -y /home/zulip/deployments/current/scripts/zulip-puppet-apply -f pg_dropcluster 9.5 main --stop systemctl stop postgresql pg_upgradecluster -m upgrade 9.3 main pg_dropcluster 9.3 main apt remove postgresql-9.3 systemctl start postgresql service memcached restart

  5. Finally, we need to reinstall the current version of Zulip, which among other things will recompile Zulip's Python module dependencies for your new version of Python:

    bash rm -rf /srv/zulip-venv-cache/* /home/zulip/deployments/current/scripts/lib/upgrade-zulip-stage-2 \ /home/zulip/deployments/current/ --ignore-static-assets

This will finish by restarting your Zulip server; you should now be able to navigate to its URL and confirm everything is working correctly.

  1. Upgrade from Xenial to Bionic, so that you are running a supported operating system.

Upgrading from Debian Stretch to Debian Buster

  1. Upgrade your server to the latest Zulip 2.1.x release. You can only upgrade to Zulip 3.0 and newer after completing this process, since newer releases don't support Ubuntu Debian Stretch.

  2. Same as for Bionic to Focal.

  3. Follow Debian's instructions to upgrade the OS.

When prompted for you how to upgrade configuration files for services that Zulip manages like Redis, PostgreSQL, Nginx, and memcached, the best choice is N to keep the currently installed version. But it's not important; the next step will re-install Zulip's configuration in any case.

  1. As root, upgrade the database installation and OS configuration to match the new OS version:

    bash apt remove upstart -y /home/zulip/deployments/current/scripts/zulip-puppet-apply -f pg_dropcluster 11 main --stop systemctl stop postgresql pg_upgradecluster -m upgrade 9.6 main pg_dropcluster 9.6 main apt remove postgresql-9.6 systemctl start postgresql service memcached restart

  2. Finally, we need to reinstall the current version of Zulip, which among other things will recompile Zulip's Python module dependencies for your new version of Python:

    bash rm -rf /srv/zulip-venv-cache/* /home/zulip/deployments/current/scripts/lib/upgrade-zulip-stage-2 \ /home/zulip/deployments/current/ --ignore-static-assets

This will finish by restarting your Zulip server; you should now be able to navigate to its URL and confirm everything is working correctly.

  1. Upgrade to the latest Zulip release, now that your server is running a supported operating system.

  2. Debian Buster has a different version of the low-level glibc library, which affects how PostgreSQL orders text data (known as "collations"); this corrupts database indexes that rely on collations. Regenerate the affected indexes by running:

bash /home/zulip/deployments/current/scripts/setup/reindex-textual-data --force

  1. As root, finish by verifying the contents of the full-text indexes:

    bash /home/zulip/deployments/current/manage.py audit_fts_indexes

Upgrading PostgreSQL

Starting with Zulip 3.0, we use the latest available version of PostgreSQL at installation time (currently version 13). Upgrades to the version of PostgreSQL are no longer linked to upgrades of the distribution; that is, you may opt to upgrade to PostgreSQL 13 while running Ubuntu 18.04 Bionic.

To upgrade the version of PostgreSQL on the Zulip server:

  1. Upgrade your server to the latest Zulip release (at least 3.0).

  2. Stop the server, as the zulip user:

    ```bash

    On Zulip before 4.0, use supervisor stop all instead

    /home/zulip/deployments/current/scripts/stop-server ```

  3. Take a backup, in case of any problems:

    bash /home/zulip/deployments/current/manage.py backup --output=/home/zulip/postgresql-upgrade.backup.tar.gz

  4. As root, run the database upgrade tool:

    bash /home/zulip/deployments/current/scripts/setup/upgrade-postgresql

  5. As the zulip user, start the server again:

    ```bash

    On Zulip before 4.0, use restart-server instead of start-server instead

    /home/zulip/deployments/current/scripts/start-server ```

You should now be able to navigate to the Zulip server's URL and confirm everything is working correctly.

Modifying Zulip

Zulip is 100% free and open source software, and you're welcome to modify it! This section explains how to make and maintain modifications in a safe and convenient fashion.

If you do modify Zulip and then report an issue you see in your modified version of Zulip, please be responsible about communicating that fact:

If you're looking to modify Zulip by applying changes developed by the Zulip core team and merged into master, skip to this section.

Making changes

One way to modify Zulip is to just edit files under /home/zulip/deployments/current and then restart the server. This can work OK for testing small changes to Python code or shell scripts. But we don't recommend this approach for maintaining changes because:

Instead, we recommend the following GitHub-based workflow (see our Git guide if you need a primer):

cd zulip
git checkout -b acme-branch 2.0.4

git commit -a

# Use `git diff` to verify your changes are what you expect
git diff 2.0.4 acme-branch

# Push the changes to your GitHub fork
git push origin +acme-branch

This workflow solves all of the problems described above: your change will be compiled and installed correctly (restarting the server), and your changes will be tracked so that it's convenient to maintain them across future Zulip releases.

Upgrading to future releases

Eventually, you'll want to upgrade to a new Zulip release. If your changes were integrated into that Zulip release or are otherwise no longer needed, you can just upgrade as usual. If you upgraded to master; review that section again; new maintenance releases are likely "older" than your current installation and you might need to upgrade to the master again rather than to the new maintenance release.

Otherwise, you'll need to update your branch by rebasing your changes (starting from a clone of the zulip/zulip repository). The example below assumes you have a branch off of 2.0.4 and want to upgrade to 2.1.0.

cd zulip
git fetch --tags upstream
git checkout acme-branch
git rebase --onto 2.1.0 2.0.4
# Fix any errors or merge conflicts; see Zulip's Git guide for advice

# Use `git diff` to verify your changes are what you expect
git diff 2.1.0 acme-branch

git push origin +acme-branch

And then use upgrade-zulip-from-git to install your updated branch, as before.

Making changes with docker-zulip

If you are using docker-zulip, there are two things that are different from the above:

Applying changes from master

If you are experiencing an issue that has already been fixed by the Zulip development community, and you'd like to get the fix now, you have a few options. There are two possible ways you might get those fixes on your local Zulip server without waiting for an official release.

Applying a small change

Many bugs have small/simple fixes. In this case, you can use the Git workflow described above, using:

git fetch upstream
git cherry-pick abcd1234

instead of "making changes locally" (where abcd1234 is the commit ID of the change you'd like).

In general, we can't provide unpaid support for issues caused by cherry-picking arbitrary commits if the issues don't also affect master or an official release.

The exception to this rule is when we ask or encourage a user to apply a change to their production system to help verify the fix resolves the issue for them. You can expect the Zulip community to be responsive in debugging any problems caused by a patch we asked you to apply.

Also, consider asking whether a small fix that is important to you can be added to the current stable release branch (E.g. 2.1.x). In addition to scheduling that change for Zulip's next bug fix release, we support changes in stable release branches as though they were released.

Upgrading to master

Many Zulip servers (including chat.zulip.org and zulip.com) upgrade to master on a regular basis to get the latest features. Before doing so, it's important to understand how to happily run a server based on master.

For background, it's backporting arbitrary patches from master to an older version requires some care. Common issues include:

While it's possible to backport these sorts of changes, you're unlikely to succeed without help from the core team via a support contract.

If you need an unreleased feature, the best path is usually to upgrade to Zulip master using upgrade-zulip-from-git. Before upgrading to master, make sure you understand:

Contributing patches

Zulip contains thousands of changes submitted by volunteer contributors like you. If your changes are likely to be of useful to other organizations, consider contributing them.