@Marvin Can create a Secret storage block in JSON format? I want to have a single storage block that I can call specific components.

To create a Secret storage block in JSON format, you can use Prefect's

Block

class. Below is an example. This block will store secrets using

SecretStr

. ### Step-by-step guide 1. Define the block class. 2. Save the block instance to access it later.

python
from typing import Optional
from prefect.blocks.core import Block
from pydantic import SecretStr

class CustomSecrets(Block):
    api_key: SecretStr
    db_password: SecretStr

# Create an instance of the block
secrets_block = CustomSecrets(
    api_key="your_api_key",
    db_password="your_db_password"
)

# Save the block
secrets_block.save(name="custom-secrets-block")

### JSON Representation Once you save the block, it will be stored in Prefect’s storage which you can retrieve later. Prefect serializes the block internally, so you don’t need to manually create a JSON representation. ### Documentation and Example Links - Prefect Block Documentation - Code Example Flow If you have any further questions or need more detailed steps, feel free to ask.

@Marvin Can I update this block in the cloud UI later?

Yes, you can update the block in the Prefect Cloud UI. Here’s how you can handle updates: 1. Modify the Block Definition: Update your existing block class definition to include any new fields you may want.

python
class CustomSecrets(Block):
    api_key: SecretStr
    db_password: SecretStr
    new_field: Optional[str] = None  # Example of a new field

2. Migrate Existing Blocks: You can migrate existing blocks to the new version. Below is an example illustrating how to bypass Pydantic validation and save the updated block.

python
# Load the existing block, bypassing validation
secrets_block = CustomSecrets.load("custom-secrets-block", validate=False)

# Set the new field to an appropriate value
secrets_block.new_field = "new_value"

# Overwrite the old block values
secrets_block.save(name="custom-secrets-block", overwrite=True)

3. Register New Block Types with Prefect Cloud: Ensure your new block type is registered with Prefect Cloud or your self-hosted Prefect server to be accessible in the UI. ### Full Example Here’s how you might incorporate these steps:

python
from typing import Optional
from prefect.blocks.core import Block
from pydantic import SecretStr

# Updated block definition
class CustomSecrets(Block):
    api_key: SecretStr
    db_password: SecretStr
    new_field: Optional[str] = None  # new field added
    
# Load existing block, bypass validation
secrets_block = CustomSecrets.load("custom-secrets-block", validate=False)

# Set the new field to a particular value
secrets_block.new_field = "new_value"

# Save the updated block, overwriting the old values
secrets_block.save(name="custom-secrets-block", overwrite=True)

### Documentation Links: - Prefect Block Documentation Updating your block through Prefect Cloud UI makes it straightforward to manage and modify storage blocks based on evolving requirements. If you need further details or assistance, feel free to ask.

@Marvin How do I set the block type metadata?

Setting block type metadata in Prefect allows you to customize how blocks are displayed and managed in the UI. This includes attributes like display names, unique slugs, logos, and descriptions. ### Metadata Fields The following metadata fields can be added to a block subclass: - `_block_type_name`: Display name in the UI. If omitted, defaults to the class name. - `_block_type_slug`: Unique slug used in the API. Defaults to a lowercase, dash-delimited version of the block type name. - `_logo_url`: URL for an image displayed in the UI. - `_description`: Short description, defaults to the docstring if provided. - `_code_example`: Short code snippet shown in the UI. ### Example Here is how you might define a block with these metadata fields:

python
from typing import Optional
from prefect.blocks.core import Block
from pydantic import SecretStr

class CustomSecrets(Block):
    _block_type_name = "Custom Secrets"
    _block_type_slug = "custom-secrets"
    _logo_url = "<http://example.com/logo.png>"
    _description = "A block to hold custom secret values"
    _code_example = """from prefect import flow, task
from my_blocks import CustomSecrets

@flow
def use_custom_secrets():
    secrets = CustomSecrets.load("custom-secrets-block")
    print(secrets.api_key)"""

    api_key: SecretStr
    db_password: SecretStr

# Create and save the block instance
secrets_block = CustomSecrets(api_key="your_api_key", db_password="your_db_password")
secrets_block.save(name="custom-secrets-block")

In the example above, we define a

CustomSecrets

block with additional metadata fields for better UI representation. After defining the block, you save it. ### How to Use 1. Define Your Block: Include metadata fields that help Prefect Cloud UI better represent your block. 2. Save the Block: Create an instance and save it, as shown in the example. ### Documentation Links - Prefect Block Documentation This way, you can manage and visualize your blocks more effectively in Prefect Cloud. If you have more questions, feel free to ask.

@Marvin How do I load that block in a separate script?

Loading a block in a separate script is straightforward. You can use the

load

method of the

Block

class to retrieve the block using its name. Here's an example of how you can load the

CustomSecrets

block defined in the previous steps in a separate script: ### Example Script

python
from prefect.blocks.core import Block
from my_blocks import CustomSecrets  # Ensure you import your custom block class

# Load the block by its name
secrets_block = CustomSecrets.load("custom-secrets-block")

# Access the block's attributes
print(f"API Key: {secrets_block.api_key.get_secret_value()}")
print(f"DB Password: {secrets_block.db_password.get_secret_value()}")

# You may use this block in your tasks or flows as needed

### Steps to Follow 1. Ensure You Have the Custom Block Class: Make sure the script has access to the

CustomSecrets

class. This often means you need to import it from wherever you defined it (

my_blocks

in this example). 2. Load the Block: Use the

load

method with the block's registered name (

"custom-secrets-block"

). ### Important Notes - Ensure the Script Environment Matches: Ensure the environment where the script runs can access Prefect's storage and has any necessary credentials. - Secure Access: If the block contains sensitive information (like secrets), handle the loaded data securely. ### Full Script Example

python
from prefect.blocks.core import Block
from my_blocks import CustomSecrets  # Ensure you import your custom block class

def main():
    # Load the block by its name
    secrets_block = CustomSecrets.load("custom-secrets-block")
    
    # Access the block's attributes safely
    api_key = secrets_block.api_key.get_secret_value()
    db_password = secrets_block.db_password.get_secret_value()
    
    print(f"Loaded API Key: {api_key}")
    print(f"Loaded DB Password: {db_password}")

if __name__ == "__main__":
    main()

### Additional Documentation - Prefect Block Documentation This script will load the

CustomSecrets

block and print the sensitive information it contains. Modify the script to fit your specific use case, such as using the secrets in tasks or flows. If you have more questions, feel free to ask.

@Marvin How do I undo the registration of the custom block?

To undo or deregister a custom block in Prefect, you need to use the Prefect Cloud or Prefect Server UI to delete the registered block. Here are the general steps you can follow: ### Steps to Deregister/Delete a Custom Block 1. Go to the Prefect Cloud UI or Prefect Server UI: Open your Prefect Cloud or Prefect Server instance in your web browser. 2. Navigate to the Blocks Section: Find the section where blocks are listed. This is usually under the "Blocks" or "Storage" menu. 3. Find Your Custom Block: Search for or navigate to your custom block (in this case, "Custom Secrets"). 4. Delete the Block: Use the UI options to delete or remove the block. This will deregister the block from Prefect. ### Using the CLI (If Deletion is Supported) While there isn't a direct command to deregister a block via the CLI, you might be able to manage blocks using the Prefect API or manually deleting them from the storage backend. However, this approach is more technical and platform-specific (e.g., you might need to interact with a database if using Prefect Server). ### Blocking it Manually via Code If you have direct access to manage the Prefect backend, you can use the API to delete blocks programmatically, but the UI method is recommended for ease and safety. ### Summary of Documentation Here is the summary of documentation regarding block registration and management: - Registration: - Register blocks with CLI:

prefect block register --module your_module

or

prefect block register --file your_block.py

. - Once registered, blocks can be viewed and managed via the Prefect UI. - Deletion: - Deletion is managed via the Prefect UI. ### Reference Links - Prefect Block Documentation If you follow these steps, you should be able to successfully deregister or delete your custom block from Prefect Cloud or Prefect Server. If you need further assistance, feel free to ask.