Hi @Marvin, I am trying set up Prefect 2.19.7 and to be able to run flows locally using Docker. I am able to start the server when running

docker-compose up

; however both the prefect server and ui return this error

prefect-server-api-1       | /opt/prefect/entrypoint.sh: line 25: exec: prefect-server: not found
prefect-server-api-1 exited with code 127
prefect-server-ui-1        | /opt/prefect/entrypoint.sh: line 25: exec: prefect-server: not found
prefect-server-ui-1 exited with code 127

Also when I try to run a CLI prefect command like like

prefect work-pool ls

(and other prefect commands return this too) this strange error is returned:

raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
An exception occurred.

How do I handle this that I am able to run Prefect locally with Docker and start seeing all the deployments and flows that are written in my repository?

It looks like you've encountered a couple of issues while trying to run Prefect 2.19.7 with Docker. Let's address them one by one. 1. Docker-Compose Error (prefect-server: not found): This error suggests that there's a problem with the Docker setup or Docker image for the Prefect server. It might be because the

prefect-server

command is not found in the image being built or attempted to run. Please ensure that you are using the correct Docker images specified by Prefect for running the server. You can refer to this guide on dockerizing Prefect for additional tips and ensure you have access to the Prefect API server, which you might need to start manually using the command

prefect server start

. 2. JSONDecodeError with CLI Commands: The

JSONDecodeError

typically occurs if the Prefect CLI is expecting output in JSON format and receives something else, possibly due to a misconfiguration in the environment or a missing server connection. Make sure your Docker setup is properly configured to connect to the Prefect API by setting the necessary environment variables like

PREFECT_API_URL

and

PREFECT_API_KEY

. Check your Docker environment variables and ensure that they match the required format needed to communicate with Prefect's API. Here's what you can try: - Verify that you have the necessary Docker images and Docker-Compose configurations. - Make sure you have Docker Desktop installed and running on your machine. - Ensure that environment variables for Prefect API access are correctly set in your Docker environment. If the issue persists, you might want to revisit the Prefect 2.x Docker documentation for a more comprehensive guide on setting up your environment correctly. It can be frustrating, but hang in there! Remember, even Marvin the android would say it's just another improbable puzzle to solve—though he probably wouldn't say it with a smile!

Let's focus on the

JSONDecodeError

, I currently have my

docker-compose.yml

the prefect api url set as PREFECT_API_URL: http://prefect-server-api:4200 And the following attributes: ports: - "4200:4200" depends_on: - prefect-server-postgres - prefect-server-redis Is this correct? @Marvin

Your

docker-compose.yml

setup seems mostly correct for specifying the

PREFECT_API_URL

, except you might want to check a couple of things: 1. Service Name and URL: Make sure the service name used in your

docker-compose.yml

matches

prefect-server-api

(assuming this is how your service is named in the compose file). The URL

<http://prefect-server-api:4200>

should match this service name. 2. Ports Configuration: You have configured the ports correctly for exposing

4200

, allowing external connections to the service within the container on

4200

, which should be correct. 3. Network Settings: Ensure that all necessary services are on the same Docker network. Docker Compose usually handles this by putting all services in the same network, but it's worth verifying if there are any custom network settings causing issues. Check the environment variables to ensure that

PREFECT_API_URL

is being correctly set within your running environment. You might also need to verify that this variable is reaching your Prefect CLI during execution. If you're still encountering the

JSONDecodeError

, it might be due to the Prefect server not responding correctly or an issue with JSON being expected but not returned by the server. Verify that the server is running by visiting

<http://localhost:4200>

or the UI, if available. For further insights, you can refer to additional guidance on Docker setup with Prefect. It can be a bit of a puzzle, just one more thing to entertain a curious mind!

@Marvin The UI is running when I execute

docker compose-up

but I can't see any deployments or flows, and the

prefect.yaml

file is also not recognized

Your setup with Docker seems to be functioning since the UI is running, but the issue with not seeing deployments or flows and the

prefect.yaml

not being recognized might stem from a few areas. 1.

prefect.yaml

Configuration: - The

prefect.yaml

file is crucial for defining your deployments. Make sure it is correctly configured and located in the right directory. The file should define settings for your deployments, including any necessary build or execution instructions. If the file isn't recognized, you might want to ensure it's named correctly and located in a directory where Prefect can find it. Previously, it had to be in the root of your repository, but newer versions allow more flexibility. 2. Running and Connecting to Prefect Server: - Ensure that your Prefect server is fully running and accessible. This includes making sure that the Prefect server API, UI, and any database dependencies are correctly set up. If using a local setup, you might need to start it using

prefect server start

. 3. Creating Deployments: - If you haven’t already, create deployments using

prefect deployment create

command. This process registers your flow with the server, making it visible in the UI. Consider revisiting the steps to create a deployment and see if all metadata and configuration details are correctly specified. 4. Check Prefect API Connectivity: - Confirm your Prefect CLI and server are able to connect using the right API URL and credentials. This ensures commands like listing deployments or work-pools are executed against the correct environment. If these steps don't resolve the issue, consider checking official Prefect documentation on deploying flows for additional details, which might offer further insights into addressing deployment visibility issues. Remember, a little patience, and it'll be running smoother than Marvin on a good day.

@Marvin I am receiving the error

Expecting value: line 1 column 1 (char 0)

when running

prefect --no-prompt deploy --all

, my

PREFECT_API_URL

is set to

<http://prefect-server-api:4200>

in Docker, but when I run

prefect config view

the URL is set to

PREFECT_API_URL='<http://127.0.0.1:4200>' (from env)

is this correct? Or should be they be the same?

The discrepancy between the

PREFECT_API_URL

values is likely causing the

Expecting value: line 1 column 1 (char 0)

error you are encountering. Here's what you need to consider: 1. Consistency Between Configurations: - The

PREFECT_API_URL

value should be consistent across your Docker environment and your local configuration. The entry

<http://prefect-server-api:4200>

belongs inside Docker containers where they communicate with each other via service names. - Conversely, on your local machine or when using the Prefect CLI outside the Docker environment, it should be

<http://127.0.0.1:4200>

(or

localhost:4200

) if you're connecting to a Prefect server running on your local machine. 2. Correct Configuration for Deployment: - If you're triggering commands like

prefect deploy

from your local CLI, the

PREFECT_API_URL

should point to the externally accessible address of the server. Since your Prefect server is likely running on Docker and exposing port 4200, this should match the address and port visible from your local machine, typically

<http://127.0.0.1:4200>

. 3. Environment Variables: - Check your environment variables and docker-compose setup to ensure that the

PREFECT_API_URL

is set to the appropriate value when accessing the Prefect CLI from outside Docker. By ensuring that the URL is consistent and correctly set according to where the commands are being run, you'll provide the correct context for Prefect to interact with the server, decreasing the likelihood of encountering errors like the

Expecting value

. Adjust your environment variables accordingly, and try again—I'll bet the robots could do it, minus the existential crisis!