Package: pg-chameleon
pg_chameleon is a MySQL to PostgreSQL replica system written in Python 3.
The system use the library mysql-replication to pull the row images from MySQL which are stored into PostgreSQL as JSONB.
A pl/pgsql function decodes the jsonb values and replays the changes against the PostgreSQL database.pg_chameleon  2.0is available on pypiThe documentationis available on pgchameleon.orgPlease submit yourbug reports on GitHub.RequirementsReplica hostOperating system: Linux, FreeBSD, OpenBSD
Python: CPython 3.5+PyMySQLmysql-replicationpsycopg2PyYAMLtabulaterollbardaemonizeOptionals for building documentationsphinxsphinx-autobuildOrigin databaseMySQL 5.5+Aurora MySQL 5.7+Destination databasePostgreSQL 9.5+Example scenariosAnalyticsMigrationsData aggregation from multiple MySQL databasesFeaturesRead from multiple MySQL schemas and  restore them it into a target PostgreSQL  database. The source and target schema names can be different.Setup PostgreSQL to act as a MySQL replica.Support for enumerated and binary data types.Basic DDL Support (CREATE/DROP/ALTER TABLE, DROP PRIMARY KEY/TRUNCATE, RENAME).Discard of rubbish data coming from the replica.Conservative approach to the replica. Tables which generate errors are automatically excluded from the replica.Possibilty to refresh single tables or single schemas.Basic replica monitoring.Detach replica from MySQL for migration support.Data type override (e.g. tinyint(1) to boolean)Daemonised init_replica process.Daemonised replica process with two separated subprocess, one for the read and one for the replay.Rollbar integrationSupport for geometrical data.Requires PostGIS on the target database.Minimal locking during init_replica for transactional engines (e.g. innodb)CaveatsThe replica requires the tables to have a primary or unique key. Tables without primary/unique key are initialised during the init_replica process but not replicated.The copy_max_memory is just an estimate. The average rows size is extracted from mysql’s informations schema and can be outdated.
If the copy process fails for memory error check the failing table’s row length and the number of rows for each slice.Python 3 is supported only from version 3.5 as required by mysql-replication .The lag is determined using the last received event timestamp and the postgresql timestamp. If the mysql is read only the lag will increase because
no replica event is coming in.The detach replica process resets the sequences in postgres to let the database work standalone. The foreign keys from the source MySQL schema are extracted and created initially as NOT VALID.  The foreign keys are created without the ON DELETE or ON UPDATE clauses.
A second run tries to validate the foreign keys. If an error occurs it gets logged out according to the source configuration.SetupRPM PGDGpg_chameleon is included in the PGDG RMP repository thanks to Devrim.Please follow the instructions onhttps://www.postgresql.org/download/linux/redhat/openSUSE Build Servicepg_chameleon is available on theopenSUSE build ServiceCurrently all releases are supported except SLE_12_SP5 because of unresolved dependencies.Virtual env setupCreate a virtual environment (e.g. python3 -m venv venv)Activate the virtual environment (e.g. source venv/bin/activate)Upgrade pip withpip install pip –upgradeInstall pg_chameleon withpip install pg_chameleon.Create a user on mysql for the replica (e.g. usr_replica)Grant access to usr on the replicated database (e.g. GRANT ALL ON sakila.* TO ‘usr_replica’;)Grant RELOAD privilege to the user (e.g. GRANT RELOAD ON *.* to ‘usr_replica’;)Grant REPLICATION CLIENT privilege to the user (e.g. GRANT REPLICATION CLIENT ON *.* to ‘usr_replica’;)Grant REPLICATION SLAVE privilege to the user (e.g. GRANT REPLICATION SLAVE ON *.* to ‘usr_replica’;)Configuration directoryThe system wide install is now supported correctly.The configuration is set with the commandchameleon set_configuration_filesin $HOME/.pg_chameleon .
Inside the directory there are three subdirectories.configuration is where the configuration files are stored.pid is where the replica pid file is created. it can be changed in the configuration filelogs is where the replica logs are saved if log_dest is file. It can be changed in the configuration fileYou should  use config-example.yaml as template for the other configuration files.
Check theconfiguration file referencefor an overview.