Upgrading BHIMA

This page provides notes on how upgrades to BHIMA work. Note that these steps are quite manual, and we would like to automate them in the future.

BHIMA Versions

BHIMA uses git tags to tag changes on the master branch and Github Releases to cut releases. The latest version is always the latest tag/release on git and Github respectively. The latest release is always available from the link https://github.com/IMA-WorldHealth/bhima/releases/latest.

While git effectively manages changes with code, some changes require changes to underlying production data - for example, adding a column to a database table, reassigning foreign keys, etc. These changes are kept in the server/models/migrations/ directory in the BHIMA repository. Within this directory are a series of folders, named in the form v.old.release-v.new.release. They contain a single SQL file (generally called migrate.sql) that is needed to upgrade from v.old.release to v.new.release. For example, the file v1.12.1-v1.13.0/migrate.sql would migrate the database from version 1.12.1 to version 1.13.0.

New changes (e.g. unreleased changes) are kept in server/models/migrations/next/ folder. In preparation for a new release, these changes are combined and renamed into the format v.old-release-v.new-release described above.

Note: not all releases require changes to data structures. Therefore, not all version changes will have an associated migrate.sql file.

When upgrading from an old version to a new version, it is important to run all migrate.sql files in order from the oldest to the newest. Unfortunately, once in a these files fail on a production database where changes were made without checking into the source code the data structure. Please let us know if you find that.

Notes on database migrations

Changes to stored procedures, triggers, and functions are not tracked in migration scripts. This is because they are due to frequent change and are already stored in the server/models directory. Therefore, it is sufficient to simply rebuild them from source.

To help with this operation, BHIMA provides a migration helper script that can be invoked with npm run migrate. This script does several things:

1. Drops all the triggers
2. Drops all routines
3. Combines triggers, functions, and procedures from source
4. Writes out data to migration-$DATABASE.sql file

where $DATABASE is the name of the production database. Now that the data is written out, it is can be run on the production database with the command mysql $DATABASE < migration-$DATABASE.sql. As with all operations on production databases, always take a backup snapshot first.

Getting the latest release

As mentioned above, releases are managed on Github. There are two ways to obtain the latest release - either by downloading a zipped directory from Github or using git to pull the latest changes and check out the latest tag. If you have deployed from Digital Ocean, the deployment was made via zip download and you must use that method. Most development deployments are made with git and simply checking out the latest version is sufficient.

Steps to Upgrade

The basic steps to upgrade now are:

1. Obtain the latest release either by downloading and unzipping or checking out the tag with git.
2. Run npm install to upgrade dependencies.
3. Run NODE_ENV=production npm run build to compile the latest client-side code
4. Run npm run migrate to create the migration script.
5. Run mysql $DATABASE < migration-$DATABASE.sql as described above.
6. Restart any running BHIMA instances

This should complete the steps to upgrading an existing BHIMA installation.