MySQL Adapter

1. config.toml Explanation

1.1 Example of configs/config.toml

[gravity]
domain = "default"
host = "192.168.8.227"
port = 32803
pingInterval = 10
maxPingsOutstanding = 3
maxReconnects = -1
accessToken = ""
publishBatchSize = 1000
rateLimit = 0

[source]
config = "./settings/sources.json"

[store]
enabled = true
path = "./statestore"

1.2 Parameters

Parameter	Description
gravity.domain	Sets the Gravity domain
gravity.host	Sets the Gravity NATS IP address
gravity.port	Sets the Gravity NATS port
gravity.pingInterval	Sets the Gravity ping interval
gravity.maxPingsOutstanding	Sets the maximum outstanding pings
gravity.maxReconnects	Sets the maximum number of reconnections
gravity.accessToken	Sets the Gravity access token (for authentication)
gravity.publishBatchSize	Sets the batch size for events sent to NATS
gravity.rateLimit	Sets the maximum rate (per second) for events sent to NATS (0 = no limit)
source.config	Path to the source configuration file
store.enabled	Enables persistent volume mounting (for state storage)
store.path	Path for mounting the persistent volume

INFO

The config.toml settings can also be provided via environment variables. The naming convention is as follows:

GRAVITY_ADAPTER_MYSQL_[SECTION]_[KEY]

All letters are uppercase, and underscores (_) separate the sections and keys.
Example for gravity.host:

env:
- name: GRAVITY_ADAPTER_MYSQL_GRAVITY_HOST
  value: 192.168.8.227

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2. settings.json Explanation

2.1 Example of settings/sources.json

{
    "sources": {
        "mysql_example": {
            "disabled": false,
            "host": "192.168.8.227",
            "port": 3306,
            "username": "root",
            "password": "1qaz@WSXROOT",
            "dbname": "gravity",
            "initialLoad": false,
            "tables": {
                "accounts": {
                    "event": {
                        "snapshot": "accountInitialized",
                        "create": "accountCreated",
                        "update": "accountUpdated",
                        "delete": "accountDeleted"
                    }
                }
            }
        }
    }
}

2.2 Parameters

Parameter	Description
sources.SOURCE_NAME.disabled	Whether to disable this source
sources.SOURCE_NAME.host	Sets the MySQL server IP address
sources.SOURCE_NAME.port	Sets the MySQL server port
sources.SOURCE_NAME.username	Sets the MySQL login username
sources.SOURCE_NAME.password	Sets the MySQL login password
sources.SOURCE_NAME.dbname	Sets the MySQL database name
sources.SOURCE_NAME.initialLoad	Whether to synchronize existing records during initialization
sources.SOURCE_NAME.tables.TABLE_NAME	Name of the table to capture events
sources.SOURCE_NAME.tables.TABLE_NAME.event.snapshot	Event name for initial load
sources.SOURCE_NAME.tables.TABLE_NAME.event.create	Event name for record creation
sources.SOURCE_NAME.tables.TABLE_NAME.event.update	Event name for record updates
sources.SOURCE_NAME.tables.TABLE_NAME.event.delete	Event name for record deletion

INFO

The database password can be provided via environment variables using AES encryption.
Environment variable format:

[SOURCE_NAME]_PASSWORD

Example:

env:
- name: GRAVITY_ADAPTER_MYSQL_SOURCE_SETTINGS
  value: |
    {
        "sources": {
            "mysql_example": {
                "disabled": false,
                "host": "192.168.8.227",
                "port": 3306,
                "username": "root",
                "password": "1qaz@WSXROOT",
                "dbname": "gravity",
                "initialLoad": false,
                "tables": {
                    "accounts": {
                        "event": {
                            "snapshot": "accountInitialized",
                            "create": "accountCreated",
                            "update": "accountUpdated",
                            "delete": "accountDeleted"
                        }
                    }
                }
            }
        }
    }

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3. Build

To build the adapter image, use the following command:

podman buildx build --platform linux/amd64 --build-arg="AES_KEY=**********" -t docker.io/brobridgehub/gravity-adapter-mysql:v3.0.0 -f build/docker/Dockerfile .

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4. Enable Database CDC

4.1 Enable Binlog for MySQL 8.0

vim /etc/mysql/mysql.conf.d/mysqld.cnf

[mysqld]
...
log-bin=/var/lib/mysql/binlog
binlog-format=row

4.2 Enable Binlog for MySQL 5.7

vim /etc/mysql/mysql.conf.d/mysqld.cnf

[mysqld]
...
server-id=1
log-bin=/var/lib/mysql/mysql-bin.log
binlog-format=row
max_allowed_packet=100M

4.3 Check if Binlog is Enabled

mysql> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin       | ON    |
+---------------+-------+
1 row in set (0.00 sec)

mysql> show variables like 'binlog_format';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| binlog_format | ROW   |
+---------------+-------+
1 row in set (0.00 sec)