macrometa-source-snowflake 0.0.4

Macrometa Source for extracting data from Macrometa

macrometa-source-snowflake

Singer tap that extracts data from a Snowflake database and produces JSON-formatted data following the Singer spec.

How to use it

TODO: Add proper context

If you want to run this Singer Tap independently please read further.

Install and Run

First, make sure Python 3 is installed on your system or follow these installation instructions for Mac or Ubuntu.

It's recommended to use a virtualenv:

make venv

Configuration

1. Create a config.json file with connection details to snowflake, here is a sample config file.

Note: tables is a mandatory parameter as well to avoid a long-running catalog discovery process. Please specify fully qualified table and view names and only that ones that you need to extract otherwise you can end up with very long running discovery mode of this tap. Discovery mode is analysing table structures but Snowflake doesn't like selecting lot of rows from INFORMATION_SCHEMA or running SHOW commands that returns lot of rows. Please be as specific as possible.

2. Run it in discovery mode to generate a properties.json

3. Edit the properties.json and select the streams to replicate

4. Run the tap like any other singer compatible tap:

  macrometa-source-snowflake --config config.json --properties properties.json --state state.json

Authentication Methods

You can either use basic user/password authentication or Key Pair authentication.

User / Password authentication

Populate user and password in the config.json file

Key Pair authentication

To use key pair authentication, omit the password and instead provide the private_key_path to the unencrypted version of the private key and, optionally, the private_key_passphrase.

Discovery mode

The tap can be invoked in discovery mode to find the available tables and columns in the database:

$ macrometa-source-snowflake --config config.json --discover

A discovered catalog is output, with a JSON-schema description of each table. A source table directly corresponds to a Singer stream.

Replication methods

The two ways to replicate a given table are FULL_TABLE and INCREMENTAL.

Full Table

Full-table replication extracts all data from the source table each time the tap is invoked.

Incremental

Incremental replication works in conjunction with a state file to only extract new records each time the tap is invoked. This requires a replication key to be specified in the table's metadata as well.

To run tests:

1. Define environment variables that requires running the tests

  export MACROMETA_SOURCE_SNOWFLAKE_ACCOUNT=<snowflake-account-name>
  export MACROMETA_SOURCE_SNOWFLAKE_DBNAME=<snowflake-database-name>
  export MACROMETA_SOURCE_SNOWFLAKE_USER=<snowflake-user>
  export MACROMETA_SOURCE_SNOWFLAKE_PASSWORD=<snowflake-password>
  export MACROMETA_SOURCE_SNOWFLAKE_PRIVATE_KEY_PATH=<snowflake-pk-path>
  export MACROMETA_SOURCE_SNOWFLAKE_PRIVATE_KEY_PASSPHRASE=<snowflake-passphrase>
  export MACROMETA_SOURCE_SNOWFLAKE_WAREHOUSE=<snowflake-warehouse>

2. Install python dependencies

make venv

3. To run unit tests:

PS: There are no unit tests at the time of writing this document

make unit_test

4. To run Integration tests

make integration_test

To run formatting and linting:

make venv format pylint

License

Apache License Version 2.0

See LICENSE to see the full text.