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<@ULVA73B9P> given a prefect deployment written in...
# marvin-in-the-wild
e
@Marvin given a prefect deployment written in python like flow.deploy(image=PRIVATE_REGISTRY, ...) how can I configure the registry credentials to allowing the prefect job to pull the image?
m
To configure the registry credentials in Prefect, you'll need to set up the necessary credentials for the private registry so that Prefect can pull the image. The steps will differ slightly depending on whether you're using Prefect 2.x or 3.x. Here are the general steps: ### Prefect 2.x 1. Create Docker Registry Credentials: Prefect provides a way to store and use Docker registry credentials. Here's an example configuration:
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python
   from prefect_docker import DockerRegistryCredentials
   
   docker_registry_credentials = DockerRegistryCredentials(
       username="my_username",
       password="my_password",
       registry_url="<http://registry.hub.docker.com|registry.hub.docker.com>",
   )
   
   with docker_registry_credentials.get_client() as client:
       docker_registry_credentials.login(client)
2. Use the Credentials in Deployment: Then, you can reference these credentials in your deployment setup. Documentation link: Prefect 2.x Docker Credentials ### Prefect 3.x 1. Configure Azure Container Registry (for example): If you are using Azure, you can create a registry and configure your ACI (Azure Container Instances) work pool to use these credentials.
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bash
   export REGISTRY_NAME=<registry-name> && \
   az acr create --resource-group $RG_NAME \
   --name <registry-name> --sku Basic
2. Update Work Pool Configuration: Update your ACI work pool configuration to include the registry URL and managed identity. Documentation link: Prefect 3.x ACI Worker Configuration 3. Configure Kubernetes or other infrastructure: For Kubernetes users, set up a Kubernetes work pool and configure the registry credentials accordingly. Documentation link: Prefect 3.x Kubernetes Deployment By following these steps, you should be able to configure your private registry credentials to allow Prefect to pull the necessary images for job deployment.
e
@Marvin I get Error: There is no active flow or task run context. I did: with docker_host.get_client() as client: docker_registry_credentials.login(client) training_deployment = await training_flow.deploy(image=PRIVATE_REGISTRY) flow_run_id = await run_deployment( name=training_deployment, ...)
m
The error you're encountering, "There is no active flow or task run context," indicates that certain Prefect operations must be executed within the context of a flow or task. Let's ensure you're doing things correctly by encapsulating your operations in a proper Prefect flow. ### Correct Usage Example To ensure everything works within the Prefect context, you need to define your Prefect operations using a flow. Here’s an example of how you can do it: 1. Version Check: Ensure which version of Prefect you are using for accurate syntax and features. 2. Proper Flow Context: Make sure operations are within the context of a flow. ### Example for Prefect 2.x or 3.x Since the core logic is the same, I'll present a general structure you can adapt based on your Prefect version:
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python
from prefect import flow, task
from prefect_docker import DockerRegistryCredentials
from prefect.deployments import run_deployment

# Define your Docker credentials
docker_registry_credentials = DockerRegistryCredentials(
    username="my_username",
    password="my_password",
    registry_url="<http://registry.hub.docker.com|registry.hub.docker.com>",
)

@flow
async def main_flow():
    # Obtain Docker client within the flow context
    async with docker_registry_credentials.get_client() as client:
        await docker_registry_credentials.login(client)

        # Deploy your flow
        training_deployment = await training_flow.deploy(image=PRIVATE_REGISTRY)
        
        # Run your deployment
        flow_run_id = await run_deployment(name=training_deployment, ...)

# Actually run the flow
main_flow()
In this example: 1. Flow Definition: 
main_flow
ensures all actions occur in a Prefect context. 2. Async Context Manager: Ensure you await the async operations where required. 3. Run the Flow: 
main_flow()
initiates the entire process. ### Documentation References: - Prefect 2.x Docker Credentials - Prefect 3.x ACI Worker Configuration Ensure you adapt the script based on your Prefect version. If the error persists or you are using additional Prefect-specific APIs, please provide more details or context so I can offer a more targeted solution.
e
@Marvin In prefect 2.20, can I set in flow.run_deployment(...) a job_variables specifying imagePullSecrets: xxx with the secrets I created in k8s with the private registry credentials? I see that the job_variables of the flow.deploy(...) doesn't support this. Does the run_deployment allows to specify it?
m
In Prefect 2.20, you can use job variables when running a deployment, which allows customization of job execution details. However, setting Kubernetes-specific details like 
imagePullSecrets
directly through 
job_variables
in 
flow.run_deployment()
might not be directly supported. From the documentation, 
job_variables
can be used to pass custom environment variables and other execution parameters, but it does not specifically mention configuring Kubernetes-specific features such as 
imagePullSecrets
. ### Workaround If you need to configure 
imagePullSecrets
, consider the following workaround: 1. Manually Set in Kubernetes: Configure your Kubernetes cluster to use the image pull secrets by default or manually modify the Kubernetes deployment YAML files to include these secrets. 2. Use Prefect Kubernetes YAML Configuration: In Prefect 2.x, you can define a 
deployment.yaml
which could be manually customized to include 
imagePullSecrets
under the 
spec
section of your Kubernetes configuration. Here’s a simple example of how you can manually configure this in your YAML:
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yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: your-deployment-name
spec:
  template:
    spec:
      containers:
      - name: your-container-name
        image: your-image
      imagePullSecrets:
      - name: your-secret-name
After defining your YAML, you would typically ensure this configuration applies to your Prefect-deployed tasks by integrating it into your Prefect deployment process. ### Documentation Reference: You might want to check these guides for related operations: - Overriding Job Variables If Prefect introduces direct support for 
imagePullSecrets
in job variables or deployment configurations in future releases, it will be documented there. Meanwhile, you may have to manage Kubernetes-specific configurations outside Prefect's job variable settings.
e
@Marvin how can I "Configure Kubernetes cluster to use the image pull secrets by default or manually modify the Kubernetes deployment YAML files to include these secrets." ? Consider the prefect-worker is in prefect-system namespace which spawns a pod in prefect namespace when the python run_deployment call is executed. I don't have .yaml file with the deployment directly.
m
To configure Kubernetes to use image pull secrets by default, especially in a managed setup like Prefect where you don't directly handle the YAML deployment files, you can follow these steps: ### Use ServiceAccount with ImagePullSecrets 1. Create Image Pull Secret in Kubernetes: First, create a Kubernetes secret that stores your registry credentials. This needs to be done in both the 
prefect-system
and 
prefect
namespaces if the pods are spawned in 
prefect
.
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bash
   kubectl create secret docker-registry my-registry-secret \
     --docker-server=<your-registry-server> \
     --docker-username=<your-username> \
     --docker-password=<your-password> \
     --docker-email=<your-email> \
     -n prefect-system

   kubectl create secret docker-registry my-registry-secret \
     --docker-server=<your-registry-server> \
     --docker-username=<your-username> \
     --docker-password=<your-password> \
     --docker-email=<your-email> \
     -n prefect
2. Associate Secret with ServiceAccount: Modify the 
default
ServiceAccount in both namespaces to include the image pull secret. This ensures any pod started under these ServiceAccounts will use the image pull secret automatically. Create a YAML file 
serviceaccount.yaml
with this content:
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yaml
   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: default
     namespace: prefect-system
   imagePullSecrets:
   - name: my-registry-secret
Apply it:
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bash
   kubectl apply -f serviceaccount.yaml
Repeat for the 
prefect
namespace:
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yaml
   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: default
     namespace: prefect
   imagePullSecrets:
   - name: my-registry-secret
And apply:
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bash
   kubectl apply -f serviceaccount.yaml
3. Automatic Pod Usage: With this setup, any pod that is started in these namespaces (like the ones initiated by Prefect’s job runs) will automatically use the specified image pull secret. ### Notes: - Ensure you have appropriate permissions to modify these configurations on your Kubernetes cluster. - The secrets should be created in all namespaces where Prefect might start pods, in your case, 
prefect-system
and 
prefect
. - If Prefect changes or adds new namespaces, you will need to repeat this process for any new namespaces used. This setup allows you to ensure that all pods in these namespaces can access private container images without modifying each pod’s deployment configuration explicitly.
e
@Marvin insted of this, can I include the imagePullSecrets updating the following values.yaml : "worker: apiConfig: server config: workPool: myWP serverApiConfig: apiUrl: http://10.30.111.226:4200/api " when running: helm install prefect-worker prefect/prefect-worker --namespace=prefect-system --version 2024.8.22203404 -f values.yaml ?
m
Yes, you can modify the 
values.yaml
file for your Helm chart installation to include 
imagePullSecrets
. This approach is suitable if you're managing Prefect workers with Helm, as it allows you to customize the worker's configuration centrally using the Helm chart. Here's how you can do it: ### Update 
values.yaml
You can add the 
imagePullSecrets
field in the 
values.yaml
file under the worker's deployment configuration. Here's an example based on the structure you provided:
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yaml
worker:
  apiConfig: server
  config:
    workPool: myWP
  serverApiConfig:
    apiUrl: <http://10.30.111.226:4200/api>
  imagePullSecrets:
  - name: my-registry-secret
### Explanation: - `imagePullSecrets`: This field lists the secrets that should be used for pulling images. In this example, 
my-registry-secret
is the name of the Kubernetes secret containing your registry credentials. ### Applying the Configuration Once you've updated your 
values.yaml
, apply it using the Helm install or upgrade command:
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bash
helm install prefect-worker prefect/prefect-worker --namespace=prefect-system --version 2024.8.22203404 -f values.yaml
If you're upgrading an existing installation, use:
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bash
helm upgrade prefect-worker prefect/prefect-worker --namespace=prefect-system --version 2024.8.22203404 -f values.yaml
### Additional Considerations: - Ensure that the secret 
my-registry-secret
already exists in the 
prefect-system
namespace. - This configuration assumes the Helm chart supports 
imagePullSecrets
. This is typical for most Kubernetes deployments but double-check the specific Helm chart documentation if issues arise. By deploying these changes, any new pods created by the Prefect worker will use the specified 
imagePullSecrets
, which allows them to pull images from your private registry.
e
@Marvin ok now the prefect-system has the registry credentials but this does not solve the problem I have Because the prefect-worker spawns a pod in prefect namespace. It should be the new spawend pod to have the registry secrets. How can I achieve this?
m
To ensure that the pods spawned in the 
prefect
namespace by the Prefect worker have the correct image pull secrets, you will need to ensure that the Prefect worker deployment is configured such that all pods it spawns in the 
prefect
namespace have access to the registry credentials. Here’s how you can achieve this: 1. Create a Secret in the 
prefect
Namespace: First, ensure that your Docker registry secret exists in the 
prefect
namespace.
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bash
   kubectl create secret docker-registry my-registry-secret \
     --docker-server=<your-registry-server> \
     --docker-username=<your-username> \
     --docker-password=<your-password> \
     --docker-email=<your-email> \
     -n prefect
2. Modify 
values.yaml
for Prefect Worker: The 
prefect-worker
needs to be configured such that any pods it spawns in the 
prefect
namespace use this secret. Unfortunately, if direct support for setting 
imagePullSecrets
for spawned pods is not present in the Helm chart and Prefect deployment options, you will need an indirect approach: 3. Use Service Account with ImagePullSecrets in the 
prefect
Namespace: Manually configure the 
default
ServiceAccount in the 
prefect
namespace to automatically use your image pull secret.
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yaml
   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: default
     namespace: prefect
   imagePullSecrets:
   - name: my-registry-secret
Apply this configuration:
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bash
   kubectl apply -f serviceaccount.yaml
4. Validate Pod Creation: After configuring the 
default
ServiceAccount in the 
prefect
namespace with 
imagePullSecrets
, any new pods spawned in the 
prefect
namespace should automatically have access to the private registry. ### Summary By configuring the 
ServiceAccount
for the 
prefect
namespace, you ensure that every pod launched there will use the image pull secret for your private registry. This applies specifically because Prefect workers in the 
prefect-system
namespace launch these pods in the 
prefect
namespace, and setting up the service account here takes care of the spawned resources.
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