as-mongodb

as-mongodb

This is a Singer tap that produces JSON-formatted data following the Singer spec from a MongoDB source.

Set up local dev environment:

make setup

Activate virtual environment

. venv/bin/activate

Set up Config file

Create json file called config.json, with the following contents:

{
  "password": "<password>",
  "user": "<username>",
  "host": "<host ip address>",
  "auth_database": "<database name to authenticate on>",
  "database": "<database name to sync from>"
}

The following parameters are optional for your config file:

Name	Type	Default value	Description
srv	Boolean	false	uses a mongodb+srv protocol to connect. Disables the usage of port argument if set to True
port	Integer	false	Connection port. Required if a non-srv connection is being used.
replica_set	string	null	name of replica set
ssl	Boolean	false	can be set to true to connect using ssl
verify_mode	Boolean	true	Default SSL verify mode
include_schemas_in_destination_stream_name	Boolean	false	forces the stream names to take the form <database_name>-<collection_name> instead of <collection_name>
update_buffer_size	int	1	[LOG_BASED] The size of the buffer that holds detected update operations in memory, the buffer is flushed once the size is reached
await_time_ms	int	1000	[LOG_BASED] The maximum amount of time in milliseconds the loge_base method waits for new data changes before exiting.
full_load_on_empty_state	bool	false	[LOG_BASED] A flag which forces full load when no previous token is found in state.

All of the above attributes are required by the tap to connect to your mongo instance. here is a sample configuration file.

Run in discovery mode

Run the following command and redirect the output into the catalog file

as-mongodb --config ~/config.json --discover > ~/catalog.json

Your catalog file should now look like this:

{
  "streams": [
    {
      "table_name": "<table name>",
      "tap_stream_id": "<tap_stream_id>",
      "metadata": [
        {
          "breadcrumb": [],
          "metadata": {
            "row-count":<int>,
            "is-view": <bool>,
            "database-name": "<database name>",
            "table-key-properties": [
              "_id"
            ],
            "valid-replication-keys": [
              "_id"
            ]
          }
        }
      ],
      "stream": "<stream name>",
      "schema": {
        "type": "object"
      }
    }
  ]
}

Edit Catalog file

Using valid json, edit the config.json file

To select a stream, enter the following to the stream's metadata:

"selected": true,
"replication-method": "<replication method>",

<replication-method> must be either FULL_TABLE, INCREMENTAL or LOG_BASED, if it's INCREMENTAL, make sure to add a "replication-key".

For example, if you were to edit the example stream to select the stream as well as add a projection, config.json should look this:

{
  "streams": [
    {
      "table_name": "<table name>",
      "tap_stream_id": "<tap_stream_id>",
      "metadata": [
        {
          "breadcrumb": [],
          "metadata": {
            "row-count": <int>,
            "is-view": <bool>,
            "database-name": "<database name>",
            "table-key-properties": [
              "_id"
            ],
            "valid-replication-keys": [
              "_id"
            ],
            "selected": true,
            "replication-method": "<replication method>"
          }
        }
      ],
      "stream": "<stream name>",
      "schema": {
        "type": "object"
      }
    }
  ]
}

Run in sync mode:

as-mongodb --config ~/config.json --catalog ~/catalog.json

The tap will write bookmarks to stdout which can be captured and passed as an optional --state state.json parameter to the tap for the next sync.

Logging configuration

The tap uses a predefined logging config if none is provided, however, you can set your own config by setting the environment variable LOGGING_CONFIG_FILE as the path to the logging config. A sample config is available here.

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