permifrost

permifrost

We welcome contributions, so please feel free to submit MRs or issues if you'd like to help in any way. To get started with contributions read the Contributing section at the bottom of this README to get started.

Installation

Install the most stable version using the following command:

pip install permifrost

If you would like to work with the most up-to-date functionality in permifrost install directly from GitLab using the following command:

pip install git+https://gitlab.com/gitlab-data/permifrost.git

Usage

Use this command to check and manage the permissions of a Snowflake account.

permifrost [-v] run <spec_file> [--role] [--dry] [--diff] [--user] [--ignore-memberships]

#> permifrost run --help
Usage: permifrost run [OPTIONS] SPEC

  Grant the permissions provided in the provided specification file for
  specific users and roles

Options:
  --dry        Do not actually run, just check.
  --diff       Show full diff, both new and existing permissions, use with -v.
  --role TEXT  Run grants for specific roles. Usage: --role testrole --role
               testrole2.

  --user TEXT  Run grants for specific users. Usage: --user testuser --user
               testuser2.

  --ignore-memberships  Do not handle role membership grants/revokes
  --help       Show this message and exit.

Use this utility command to run the SnowFlake specification loader to confirm that your roles.yml file is valid.

permifrost [-v] spec-test <spec_file> [--role] [--user] [--ignore-memberships]

#>  permifrost spec-test --help
Usage: permifrost spec-test [OPTIONS] SPEC

  Load SnowFlake spec based on the roles.yml provided. CLI use only for confirming specifications are valid.

Options:
  --role TEXT           Run grants for specific roles. Usage: --role testrole
                        --role testrole2.

  --user TEXT           Run grants for specific users. Usage: --user testuser
                        --user testuser2.

  --ignore-memberships  Do not handle role membership grants/revokes
  --run-list TEXT       Run grants for specific users. Usage: --user testuser
                        --user testuser2.

  --help                Show this message and exit.

Given the parameters to connect to a Snowflake account and a YAML file (a "spec") representing the desired database configuration, this command makes sure that the configuration of that database matches the spec. If there are differences, it will return the sql grant and revoke commands required to make it match the spec. If there are additional permissions set in the database this command will create the necessary revoke commands with the exception of:

• Object Ownership
• Warehouse Privileges

Furthermore, if you are using the recommended role of SECURITYADMIN, ALTER USER ... commands will fail on users that are owned by ACCOUNTADMIN. In these circumstances, it is highly recommended to log into the Snowflake instance and update ownership of all users to belong to USERADMIN as per Snowflake recommended best practices.

Lastly, note that the default roles cannot have their role hierarchies modified. As such, any GRANT ROLE <default role> TO ROLE <default role>; will be excluded from the permission set generated by Permifrost.

For example:

...
roles:
  public:
    member_of:
      - useradmin
  securityadmin:
    member_of:
      - useradmin
...

Both of the above relationships will be skipped as this attempts to modify a default Snowflake permission structure which would generate an error on attempting to implement.

Permifrost is heavily inspired by pgbedrock which can be used for managing the permissions in a Postgres database.

spec_file

The YAML specification file is used to define in a declarative way the databases, roles, users and warehouses in a Snowflake account, together with the permissions for databases, schemas and tables for the same account.

All permissions are abbreviated as read or write permissions, with Permifrost generating the proper grants for each type of object. This includes shared databases which have simpler and more limited permissions than non-shared databases.

According to the read vs. write permissions approach, you should be able to grant granular access like read permissions for usage of database and schema and write permissions to insert data into a specific table within that database and schema.

Please find below the links between Permifrost permissions and Snowflake grants.

Objects	Permifrost permissions	Snowflake grants
Databases	read	usage
	write	monitor, create schema
Schemas	read	usage
	write	monitor, create table, create view, create stage, create file format, create sequence, create function, create pipe
Table	read	select
	write	insert, update, delete, truncate, references

Tables and views are listed under tables and handled properly behind the scenes.

If * is provided as the parameter for tables the grant statement will use the ALL <object_type>s in SCHEMA syntax. It will also grant to future tables and views. See Snowflake documentation for ON FUTURE

If a schema name includes an asterisk (prefix or suffix), such as snowplow_* or *_snowplow, then all schemas that match this pattern will be included in the grant statement unless it is for ownership, in which case the asterisk is not supported. This can be coupled with the asterisk for table grants to grant permissions on all tables in all schemas that match the given pattern. This is useful for date-partitioned schemas.

All entities must be explicitly referenced. For example, if a permission is granted to a schema or table then the database must be explicitly referenced for permissioning as well. Additionally, role membership must be explicit in the config file. If a role does not have a member_of list, it will have all roles it currently has revoked.

Roles can accept "_" as a role name either alone or nested under the include key. There is optionally an exclude key that can be used if include is used. "_"will grant membership to all roles defined in the spec. Any roles defined inexcludewill be removed from the list defined ininclude.

Objects like warehouses and integrations that only have one permifrost permission type just needs to be specified in the role (see below).

Objects can have a meta dictionary which may contain information that is not relevant for Permifrost's execution and are ignored by Permifrost itself.

A specification file has the following structure:

# Databases
databases:
    - db_name:
        shared: boolean
    - db_name:
        shared: boolean
        owner: role_name
        meta:
            some_key: some_value
            ...
    ... ... ...

# Roles
roles:
    - role_name:
        warehouses:
            - warehouse_name
            - warehouse_name
            ...

        member_of:
            - role_name
            - role_name
            ...

            # or

        member_of:
            include:
                - "*"
            exclude:
                - role_name

        privileges:
            databases:
                read:
                    - database_name
                    - database_name
                    ...
                write:
                    - database_name
                    - database_name
                    ...
            schemas:
                read:
                    - database_name.*
                    - database_name.schema_name
                    - database_name.schema_partial_*
                    - database_name.*_schema_partial

                    ...
                write:
                    - database_name.*
                    - database_name.schema_name
                    - database_name.schema_partial_*
                    - database_name.*_schema_partial
                    ...
            tables:
                read:
                    - database_name.*.*
                    - database_name.schema_name.*
                    - database_name.schema_partial_*.*
                    - database_name.*_schema_partial.*
                    - database_name.schema_name.table_name
                    ...
                write:
                    - database_name.*.*
                    - database_name.schema_name.*
                    - database_name.schema_partial_*.*
                    - database_name.*_schema_partial.*
                    - database_name.schema_name.table_name
                    ...

        owns:
            databases:
                - database_name
                ...
            schemas:
                - database_name.*
                - database_name.schema_name
                ...
            tables:
                - database_name.*.*
                - database_name.schema_name.*
                - database_name.schema_name.table_name
                ...

        meta:
            some_key: some_value
            ...

    - role_name:
        owner: role_name
    ... ... ...

# Users
# can_login is required the rest of the parameters are optional
# None of the values are validated in Snowflake, hence default_warehouse, default_namespace and default_role
# can contain invalid values
users:
    - user_name:
        can_login: boolean
        member_of:
            - role_name
            ...
        has_password: boolean
        display_name: string
        first_name: string
        middle_name: string
        last_name: string
        email: string
        comment: string
        default_warehouse: string
        default_namespace: string
        default_role: string
        meta:
            some_key: some_value
            ...
    - user_name:
        owner: role_name
    ... ... ...

# Warehouses
# Warehouse sizes are informative and not altered by Permifrost to align with the spec file
warehouses:
    - warehouse_name:
        size: x-small
        meta:
            some_key: some_value
            ...
    - warehouse_name:
        size: x-small
        owner: role_name
    ... ... ...

# Integrations
# Integration categories are informative and not altered by Permifrost to align with the spec file
integrations:
    - integration_name:
        category: storage
        meta:
            some_key: some_value
            ...
    - integration_name:
        category: security
        owner: role_name
    ... ... ...

For a working example, you can check the Snowflake specification file that we are using for testing permifrost permissions.

Note: The spec file must all be in lowercase.

Settings

All settings are declared here with their default values and are described below. These can be added to your spec.yaml file.

require-owner: false

require-owner: Set to true to force having to set the owner property on all objects defined.

--diff

When this flag is set, a full diff with both new and already granted commands is returned. Otherwise, only required commands for matching the definitions on the spec are returned.

--dry

When this flag is set, the permission queries generated are not actually sent to the server and run; They are just returned to the user for examining them and running them manually.

When this flag is not set, the commands will be executed on Snowflake and their status will be returned and shown on the command line.

Connection Parameters

The following environmental variables must be available to connect to Snowflake:

$PERMISSION_BOT_USER
$PERMISSION_BOT_ACCOUNT
$PERMISSION_BOT_WAREHOUSE

Username and Password

To connect using a username and password, also include the following:

$PERMISSION_BOT_PASSWORD
$PERMISSION_BOT_DATABASE
$PERMISSION_BOT_ROLE

Currently, Permifrost assumes you are using the SECURITYADMIN role and will fail validation if you are not.

OAuth

To connect using an OAuth token, also include the following:

$PERMISSION_BOT_OAUTH_TOKEN

External Browser SSO Auth

To connect using an external browser with SSO Auth, also include the following:

$PERMISSION_BOT_AUTHENTICATOR='externalbrowser'

Key Pair Authentication

Rather than supplying a password or an oauth token, it's possible to connect via Snowflake's Key Pair authentication by setting the following:

$PERMISSION_BOT_KEY_PATH
$PERMISSION_BOT_KEY_PASSPHRASE

See Snowflake-sqlalchemy for more info.

Contributing

Contributing to Permifrost is easy, and most commands to do so are available within the Makefile.

The easiest way to start developing is to run make initial-setup to install all the necessary packages to develop on the project. Next run make permifrost in a second terminal, this will open a shell in a docker container with the local version of Permifrost installed.

You can now make changes to the files in your editor and it will be reflected in the commands that you run from the docker shell.

To check code quality prior to committing changes, you can use make local-lint.

See the Makefile for more details.

WARNINGS

DO NOT name git branches with forward slashes / as the current CI pipeline is unable to manage names like this. (i.e. username/feature/feature-name will break the CI pipeline so username.feature.feature-name should be used instead)

This project has pre-commit hooks installed to maintain the existing code quality. As such, we strongly recommend you use a terminal to commit and push code changes. Specifically, avoid using git integrations on IDEs to make commits or pushes. Adding files through the IDE git integrations are okay, but do not commit through the IDE. Use the terminal to commit changes because it will show the output of each of the pre-commit checks to allow you to make changes as needed.

For committing work-in-progress changes use git commit --no-verify -m "WIP: <message>".

For committing finalized changes, the below workflow will identify errors and allow for easier development:

• Make your changes and git add <file name(s)>
• git commit to identify/format errors in the changed files
  • Repeat the following steps until all checks pass
  • git add <file name(s)>
  • git commit
• Add message at the prompt and save/exit the commit file
• When you are ready to push changes to the remote host, run git push origin <branch name>. This will perform additional linting/formatting checks.
  • Repeat the following steps until all checks pass
  • git push origin <branch name>
  • git add <file name(s)>
  • git commit
• Add message at the prompt and save/exit the commit file
• git push origin <branch name> until all checks pass

Releasing

See the issue template for guidance on how to release a new version of this project to PyPi