snowconvert-deploy-tool 0.0.25
Mobilize.Net Database Deploy tool for Snowflake
License: MIT

sc-deploy-db
===============

`sc-deploy-db` is a cross-platform command line tool for deploying scripts to Snowflake. 
This tool is designed to help with the deployment of large data warehouses.  

A typical challenge when deploying code to snowflake is handling dependendencies. For example if you have a
view and it depends on some other views, then your deployment will fail if you do not deploy 
the dependendencies first.

`sc-deploy-db` can handle dependendencies between objects. The tool uses a brute-force
approach in which if an object fails due to a missing dependendency it will put it a queue 
and then the deployment of that object it will retried.
The tool will keep trying to deploy until it gets to point where no more objects can be deployed.

The tool will also provide deployment logs that will help you to identify and track any deployment issues.

For projects using `SnowConvert`_ this deploy tool is highly recommended.

Also a lot of tools have limitations when deploying files that contain several code snippets. A typical error you might get is::

    000006 (0A000): Multiple SQL statements in a single API call are not supported; use one API call per statement instead.  

This tool has some options that can process the code inside the files, splitting it based on pattern before deployment helping 
in those situations. Please read more about it the following sections.

However starting on version 0.0.18 the tool can leverate the connector capabilities for running multiple statements.
The split functionality has been left for cases where this may still be needed.

Installation
------------

We recommended installing using `PYPI`_

.. code:: bash

    $ pip install snowconvert-deploy-tool --upgrade
    
.. note:: If you run this command on MacOS change `pip` by `pip3`

You might need to install the python connector for snowflake::

    pip install "snowflake-connector-python[pandas]"



Usage
-----

For information about the different parameters or options just run it using the  `-h` option:

.. code:: bash

    $ sc-deploy-db -h
    
Tool Options
------------

.. code:: bash

    usage: sc-deploy-db [-h] [-A ACCOUNT] [-D DATABASE] [-WH WAREHOUSE] [-R ROLE] [-U USER] [-P PASSWORD] [--AskPassword] [-W WORKSPACE] -I INPATH
                    [--activeConn ACTIVECONN] [--authenticator AUTHENTICATOR]  [--UseMultiStats USEMULTISTATS] [-L LOGPATH] [--SplitBefore SPLITBEFORE] [--SplitAfter SPLITAFTER]
                    [--ObjectType [OBJECTTYPE]] [--param PARAM] [--param-prefix PARAM_PREFIX] [--param-postfix PARAM_POSTFIX]

    SnowConvertStudio Deployment Script
    ===================================
    This script helps you to deploy a collection of .sql files to a Snowflake Account.
    The tool will look for settings like:
    - Snowflake Account
    - Snowflake Warehouse
    - Snowflake Role
    - Snowflake Database

    If the tool can find a **config_snowsql.ini** file in the current directory or in the **workspace\config_snowsql.ini** location
    it will read those parameters from there.
    optional arguments:

    -h, --help            show this help message and exit
    -A ACCOUNT, --Account ACCOUNT
                          Snowflake Account
    -D DATABASE, --Database DATABASE
                          Snowflake Database
    -S SCHEMA, --Schema SCHEMA
                          Snowflake Initial Schema                          
    -WH WAREHOUSE, --Warehouse WAREHOUSE
                          Snowflake Warehouse
    -R ROLE, --Role ROLE  Snowflake Role
    -U USER, --User USER  Snowflake User
    -P PASSWORD, --Password PASSWORD
                          Password
    --AskPassword         If given the tool will prompt for the password
    -W WORKSPACE, --Workspace WORKSPACE
                          Path for workspace root. Defaults to current dir
    -I INPATH, --InPath INPATH
                          Path for SQL scripts
    --activeConn ACTIVECONN
                          When given, it will be used to select connection parameters forn config_snowsql.ini or ~/.snowsql/config
    --authenticator AUTHENTICATOR
                          Use the authenticator with you want to use a different authentication mechanism
    -L LOGPATH, --LogPath LOGPATH
                          Path for process logs. Defaults to current dir
    --SplitBefore SPLITBEFORE
                          Regular expression that can be used to split code in fragments starting **BEFORE** the matching expression
    --SplitAfter SPLITAFTER
                          Regular expression that can be used to split code in fragments starting **AFTER** the matching expression
    --ObjectType [OBJECTTYPE]
                          Object Type to deploy table,view,procedure,function,macro
    --sync-folder-target SYNC_FOLDER_TARGET
                        Target folder where the lastest version of the scripts is kept
    --sync-folder-categories SYNC_FOLDER_CATEGORIES
                        It is expected that the workdir will organize code in folders like [table,view,function,macro,procedure]. This
                        parameter is a comma separated list of the categories you would like to sync                          
    --simple-output SIMPLE_OUTPUT
                          disables the usage of colors and other terminal effects
    --param PARAM         substitution parameter that will be applied before deployment they are
                          expected to be like --param paramName=Value
    --param-prefix PARAM_PREFIX
                          Prefix to use for your parameters by default it is &
    --param-postfix PARAM_POSTFIX
                          Prefix to use for your parameters by default is None

This tool assumes :

- that you have a collection of `.sql` files under a directory. 
- that all those `.sql` files will be deployed to the same database.
- that each file contains **only** one statement. If your files contain more that one statement then you should use the **--SplitBefore** or **--SplitAfter** options.

The tool can also read the connection settings from environment variables. 

The following environment variables are recognized by this tool (notice that the tool also recognizes `SNOWSQL CLI Environment Variables`_):

.. list-table:: Environmental Variables
   :widths: 25 50
   :header-rows: 1

   * - Variable Name
     - Description
   * - SNOW_USER or SNOWSQL_USER
     - The username that will be used for the connection
   * - SNOW_PASSWORD or SNOWSQL_PWD
     - The password that will be used for the connection
   * - SNOW_ROLE or SNOWSQL_ROLE
     - The snowflake role that will used for the connection
   * - SNOW_ACCOUNT or SNOWSQL_ACCOUNT
     - The snowflake accountname that will used for the connection
   * - SNOW_WAREHOUSE or SNOWSQL_WAREHOUSE
     - The warehouse to use when running the sql
   * - SNOW_DATABASE or SNOW_DATABASE
     - The database to use when running the sql

If you are a `SNOWSQL CLI`_ user, this tool can use you configuration settings, using the 
**--activeConn connectionName** parameter will search for the **[connections.connectionName]**
section in your config file.


.. note::  If your files contains several statements you can use the --SplitBefore or --SplitAfter argument, as explained below, so the tool will try to split the statements prior to execution.

Examples
--------

We recommend to have a folder structure like:::

    + code
       + procs
         proc1.sql
       + tables
         table1.sql
         + folder1
             table2.sql

If that is the case you can deploy then by running::: 

    sc-deploy-db -A my_sf_account -WH my_wh -U user -P password -I code

If you want to use another authentication like Azure AD you can do:::

    sc-deploy-db -A my_sf_account -WH my_wh -U user -I code --authenticator externalbrowser


A recommended approach is that you setup a bash shell script, for example `config.sh` with contents like:::

    export SNOW_ACCOUNT="demo.us-east-1"
    export SNOW_WAREHOUSE="DEMO_WH"
    export SNOW_ROLE="DEMO_FULL_ROLE"
    export SNOW_DATABASE="DEMODB"
    echo "Reading User and Password. When you type values wont be displayed"
    read -s -p "User: "     SNOW_USER
    echo ""
    read -s -p "Password: " SNOW_PASSWORD
    echo ""
    export SNOW_USER
    export SNOW_PASSWORD

You can then run the script like: `source config.sh`. After that you can just run `sc-deploy-db -I folder-to-deploy`


Files with multiple statements
------------------------------

If your files have multiple statements, it will cause some failures as the snowflake Python API does not allow multiple statements on a single call.::

    000006 (0A000): Multiple SQL statements in a single API call are not supported; use one API call per statement instead.  


In order to handle that, you give a tool a regular expression that can be used to split the file contents. 
This pattern could be used to split **before** using `--SplitBefore pattern` or to split **after** the pattern `--SplitAfter pattern`.

Let's see some examples. 

If you have a file with contents like:

::

    CREATE OR REPLACE SEQUENCE SEQ1
    START WITH 1
    INCREMENT BY 1;

    /* <sc-table> TABLE1 </sc-table> */
    CREATE TABLE TABLE1 (
        COL1 VARCHAR
    );

You can use an argument like `--SplitAfter ';'` that will create a fragment from the file anytime a `;` is found.::

    sc-deploy-db -A my_sf_account -WH my_wh -U user -P password -I code  --SplitAfter ';'

If you have a file with statements like:::

    /* <sc-table> TABLE2 </sc-table> */
    CREATE TABLE OR REPLACE TABLE1 (
        COL1 VARCHAR
    );

    /* <sc-table> TABLE2 </sc-table> */
    CREATE TABLE TABLE2 (
        COL1 VARCHAR
    );

You can use an argument like `--SplitBefore 'CREATE (OR REPLACE)?'`. That will create a fragment each time a `CREATE` or `CREATE OR REPLACE` fragment is found;

::

    sc-deploy-db -A my_sf_account -WH my_wh -U user -P password -I code  --SplitBefore 'CREATE (OR REPLACE)?'

You can also use something like:

::

    sc-deploy-db -A my_sf_account -WH my_wh -U user -P password -I code  --SplitBefore '\/\*[^\*]*\*\/'

To split before a block comment

Substitution parameters
-----------------------

Sometimes you need to add some substitution parameters for example:

::

    create or replace table &env_TABLE1 ( NAME VARCHAR(100), LAST_NAME VARCHAR(200));

You can then call the deployment script like `sc-deploy-db --param env=PROD` then the tool will deploy:

::

    create or replace table PROD_TABLE1 ( NAME VARCHAR(100), LAST_NAME VARCHAR(200));

By default variables are expected like `&var` or `&{var}`. You can also customize the prefix. 

For example `--param-prefix "$"` will allow you to use vars like `$var` or `${var}`.
For example `--param-prefix "<" --param-postfix ">"` will allow you to use vars like `<var>` or `<{var}>`.


Folder Syncronization
---------------------

A very common practice when using `SnowConvert`_ is to organize your files on folders per category [table,view,procedure,macro,function] 
and per schema. This makes it easier for team collaboration and progress tracking.

Another recommended practice is to have **unstabilized** code on a work directory and then run the `sc-deploy-db`, the tool
will generate execution logs with summaries of the found errors.

Data Engineers should work on removing the errors found and re-run the `sc-deploy-db`. 

At some point you might need to sync your progress on another folder. A common practice is that you will have a `Target` folder,
where you are supposed to have only the files that have been successfully deployed.

To ease that task the deploy tool provides a folder sync command. This command assumes that you have an structure like:::

    - WorkDir
        - group1
            -table
                -schema1
                   table1.sql
                   table2.sql
                -schema2
                   table3.sql
                   table4.sql
            -view
                -schema1
                   view1.sql
                -schema4
                   view5.sql
            -function
                -schema2
                   function1.sql
                   function2.sql
            -procedure
                -schema1
                  proc1.sql
                  proc2.sql


For example to syncronize tables and views this command should be executed as: ::

     sc-deploy-db -I WorkDir --sync-folder-target WorkDir/group1 --sync-folder-categories "table,view"

The tool will perform queries agains the **information_schema** tables. It will assume that the file name matches the object name.

Reporting issues and feedback
-----------------------------

If you encounter any bugs with the tool please file an issue in the
`Issues`_ section of our GitHub repo.


License
-------

sc-deploy-db is licensed under the `MIT license`_.


.. _Issues: https://github.com/MobilizeNet/SnowConvert_Support_Library/issues
.. _MIT license: https://github.com/MobilizeNet/SnowConvert_Support_Library/tools/snowconvert-deploy/LICENSE.txt
.. _SnowConvert: https://www.mobilize.net/products/database-migrations/snowconvert
.. _SNOWSQL CLI Environment Variables: https://docs.snowflake.com/en/user-guide/snowsql-start.html#connection-syntax
.. _SNOWSQL CLI: https://docs.snowflake.com/en/user-guide/snowsql.html
.. _PYPI: https://pypi.org/