Databricks Apps with FastAPI

[AndyK]

I have a FastAPI Databricks App deployed to a hosted workspace. How can I call the API from external tools like Postman?

P.S. I was able to call the API within the same browser.

[SP_6721]

Hi @AndyK ,

External tools don’t share browser’s login context, so you’ll need to add a bearer token in the Authorization header manually.

Start by generating an access token. You can either use the Databricks CLI (databricks auth token) to get an OAuth token, or create a Personal Access Token (PAT) from your workspace settings.
Then in Postman, enter your API endpoint like:
https://<workspace-host>/api/<endpoint-path>
Go to the Authorization tab, choose Bearer Token, and paste your token.

Make sure you have CAN USE permission on the Databricks App. Also, note that tokens,especially OAuth, can expire (usually in about an hour), so you might need to generate new one when needed

[AndyK]

Hi,

PAT doesn't seem to work, but we use a workspace token and it was able to go through. Thanks

[Gareema]

How to generate one?

[Gareema]

I tried generating, the token this for service principle:

export CLIENT_ID=<client-id>
export CLIENT_SECRET=<client-secret>

curl --request POST \
--url <token-endpoint-URL> \
--user "$CLIENT_ID:$CLIENT_SECRET" \
--data 'grant_type=client_credentials&scope=all-apis'

It did generates a token, but that token still doesn't work with the Databricks App i created. 
I am just passing it like:

response = requests.get(
"https://<app specific url>.azure.databricksapps.com/api/v1/table",
headers={"Authorization": f"Bearer {token} "})
print(response.json())

[Gareema]

What do you mean by workspace token? Can you elaborate a little?

[AndyK]

Hi,

Make sure your token endpoint url is like this: https://<databricks-instance>/oidc/v1/token.

Refer here for workspace-level access token: https://docs.databricks.com/aws/en/dev-tools/auth/oauth-m2m

Also make sure you have granted access of the service principal to the app: https://apps-cookbook.dev/docs/fastapi/getting_started/connections/connect_from_app