In current implementation of Kapua we hold device data in SQL database (it can MariaDB or H2 SQL Server). In order to keep SQL schema updated, we decided to use Liquibase.
Kapua broker on startup executes embedded Liquibase client which ensures that all database update scripts have been collected and applied to your database. The coordinates of database URL connection are obtained from regular Kapua settings i.e. the following system properties:
commons.db.username
commons.db.password
commons.db.schema
Liquibase clients looks up for all scripts located in the classpath matching liquibase/*.sql
pattern.
If you would like a new SQL script to your service, just add new *.sql
file to src/main/resources/liquibase
directory of your Maven project. Just keep in mind that
the name of your file should be unique, so the best way is to make it matching the name of your service module (for example device.sql
for device management).
If you would like to add new change set to existing SQL file, append new --changeset filename:number
line to your log file. The example:
--changeset device_event:2
CREATE TABLE my_new_table (
scope_id BIGINT(21) UNSIGNED NOT NULL
PRIMARY KEY (scope_id, id)
) CHARSET=utf8;
More details regarding Liquibase SQL file syntax, can be found on Liquibase web page.