@Marvin Can you clarify the difference between PREFECT_API_URL, PREFECT_SERVER_API_HOST and PREFECT_SERVER_API_BASE_PATH? I am trying to deploy Prefect v3 as an azure webapp and the UI can't connect to the api

Here's a brief explanation of the environment variables related to your Prefect deployment: 1. PREFECT_API_URL: This is the URL that Prefect clients use to communicate with the Prefect API. In a cloud deployment, you would typically set this to the URL of your Prefect Cloud API. For self-hosted setups, it would be the URL where your Prefect server API is accessible. 2. PREFECT_SERVER_API_HOST: This variable is used to specify the host address for the Prefect server's API. In many cases, this might be set to

localhost

if running locally, or it could be the IP address or domain name of a server if running in a distributed setup. 3. PREFECT_SERVER_API_BASE_PATH: This is used to specify a base path for the API when it's hosted behind a proxy or a sub-path of a domain. This might be necessary if your API is not hosted at the root of the server's domain. In your case, deploying on an Azure Web App, ensure that these variables are set correctly to reflect the network configuration of your Azure deployment. The UI needs to connect to the API using the

PREFECT_API_URL

, so make sure this URL is accessible from the webapp. For more detailed guidance, you can refer to the Prefect documentation on settings and profiles. If you encounter further issues, ensure that your network and authentication settings are correctly configured, as indicated in the documentation. No related GitHub issues were found, so if the problem persists, you might consider opening a new issue on the Prefect repository.

@Marvin What other env variables should I pay attention when deploying as a webapp from a docker?

When deploying Prefect as a web app from a Docker container, there are several environment variables you should consider configuring to ensure a smooth deployment. Here are the key ones: 1. PREFECT_API_URL: As previously mentioned, this is crucial for connecting the Prefect client to the API. 2. PREFECT_DEFAULT_DOCKER_BUILD_NAMESPACE: This variable helps in setting the namespace for Docker images, allowing you to omit the namespace from your image name during deployment. This is particularly useful if you're using a Docker registry. 3. Custom Job Variables: You can define custom variables in your

prefect.yaml

file under a

job_variables

section. These can include variables like

EXECUTION_ENVIRONMENT

and others specific to your deployment needs. 4. Source Code Location: If you're not baking your code into Docker images, you might need to specify where to pull the flow code from at runtime using the

from_source

method, pointing to a GitHub repository or other storage. 5. Environment Variable Templating: In your

prefect.yaml

, you can template environment variables using the

{{ $ENV_VAR_NAME }}

syntax to dynamically insert values from the environment where the deployment is run. For more detailed guidance, you can refer to the Prefect documentation on customizing deployments and Docker deployment examples. These configurations will help ensure your Prefect deployment is robust and adaptable to different environments.

@Marvin so if my domain is https://my-domain.net, what do the env variables should be?

To configure your Prefect deployment with the domain

<https://my-domain.net>

, you should set the environment variables as follows: 1. PREFECT_API_URL: This should be set to the full URL where the Prefect API is accessible. For example:

plaintext
   PREFECT_API_URL=<https://my-domain.net/api>

Ensure that

/api

or the appropriate path is appended if your API is not at the root of the domain. 2. PREFECT_SERVER_API_HOST: If the API is running on the same domain, you might set this to:

plaintext
   PREFECT_SERVER_API_HOST=<http://my-domain.net|my-domain.net>

However, if using a specific IP or hostname internally, adjust accordingly. 3. PREFECT_SERVER_API_BASE_PATH: If your API is hosted behind a specific path (e.g., `https://my-domain.net/prefect/api`), you should set this to:

plaintext
   PREFECT_SERVER_API_BASE_PATH=/prefect/api

Otherwise, leave it empty or set to

/

if the API is at the root. These settings assume your API is directly accessible at the domain and path specified. Adjust the base path if your API is behind additional routing or proxy paths. Always ensure that the domain and paths match how your infrastructure serves the Prefect API.

@Marvin So I do not need to include the port number?

If your Prefect API is served over standard ports—port 80 for HTTP or port 443 for HTTPS—you typically do not need to specify the port number in your URLs. These ports are assumed by default for their respective protocols. However, if your API is served over a non-standard port, you should include it in the

PREFECT_API_URL

and potentially in

PREFECT_SERVER_API_HOST

. For example, if your API is accessible at port 8080, you would set: - PREFECT_API_URL:

plaintext
  PREFECT_API_URL=<https://my-domain.net:8080/api>

- PREFECT_SERVER_API_HOST (if needed):

plaintext
  PREFECT_SERVER_API_HOST=<http://my-domain.net:8080|my-domain.net:8080>

Including the port ensures that requests are directed to the correct endpoint, especially if your server listens on a non-standard port.

@Marvin HOw about the default 4200 port

Port 4200 is commonly used for development servers, particularly in front-end frameworks like Angular. However, for a production deployment of Prefect, the default ports would typically be 80 for HTTP or 443 for HTTPS. If your Prefect API is running on port 4200, you should include it in your configuration: - PREFECT_API_URL:

plaintext
  PREFECT_API_URL=<https://my-domain.net:4200/api>

- PREFECT_SERVER_API_HOST (if applicable):

plaintext
  PREFECT_SERVER_API_HOST=<http://my-domain.net:4200|my-domain.net:4200>

Make sure that your network configuration allows traffic on port 4200 and that your server is correctly set up to handle requests on this port.