@Marvin How do I use Azure Postgres Flexible Server with Prefect-server helm

To use Azure Postgres Flexible Server with Prefect Server launched via the helm chart, follow these general steps: 1. First, ensure you have your Azure Postgres Flexible Server set up and have the connection details, such as the hostname, port, username, and password. 2. You'll need to configure Prefect Server to connect to your external Azure Postgres Flexible Server by setting an environment variable for the database connection URL. Set the following environment variable by updating your Prefect configuration:

shell
prefect config set PREFECT_API_DATABASE_CONNECTION_URL="postgresql+asyncpg://<username>:<password>@<hostname>:<port>/<dbname>"

Replace

<username>

,

<password>

,

<hostname>

,

<port>

, and

<dbname>

with the appropriate values for your Azure Postgres Flexible Server. 3. After setting the configuration, you can proceed to deploy Prefect Server with Helm. Add the necessary environment variables to your helm chart values or pass them as arguments during the Helm deployment. For example, include the following in your

values.yaml

file or pass through the

--set

flag:

yaml
env:
  PREFECT_API_DATABASE_CONNECTION_URL: "postgresql+asyncpg://<username>:<password>@<hostname>:<port>/<dbname>"

4. Deploy or update your Prefect Server release with Helm using the updated

values.yaml

file. For more detailed instructions on configuring an external PostgreSQL database with Prefect, you can refer to the official Prefect documentation. Make sure your Azure Postgres Flexible Server instance is accessible from the Kubernetes cluster where you're deploying Prefect Server.

@Marvin how do I create the secret?

apiVersion: v1
kind: Secret
metadata:
  name: db-ssl-secret
data:
  root.crt: BASE64ENCODECERTIFICATE=
type: Opaque

It seems that the tool did not provide the correct example for creating a Kubernetes secret for an SSL certificate. Here is how you can manually create the secret in Kubernetes with your SSL certificate: 1. You need to base64 encode your certificate:

shell
cat root.crt | base64

2. Replace

BASE64ENCODECERTIFICATE=

with the base64 encoded certificate output from the command above. 3. Create a secret resource file

db-ssl-secret.yaml

with the following content:

yaml
apiVersion: v1
kind: Secret
metadata:
  name: db-ssl-secret
data:
  root.crt: <base64-encoded-certificate>
type: Opaque

Make sure to replace

<base64-encoded-certificate>

with your actual encoded certificate. 4. Apply the secret to your Kubernetes cluster:

shell
kubectl apply -f db-ssl-secret.yaml

This will create a secret in your Kubernetes cluster named

db-ssl-secret

containing your SSL certificate, and you can then reference this secret in your deployments or other resources as needed. Keep in mind that the

data

field's value must be a base64 encoded string, and you should not include line breaks or additional characters.

@Marvin how do I get the root.crt

To obtain the

root.crt

for an Azure Postgres Flexible Server or any Postgres server that requires SSL, you typically follow these steps: 1. Download directly from the service: - If you are using a managed database service like Azure, they often provide a way to download the root certificate directly from the service's dashboard or documentation. 2. Use a command-line tool: - You can use

openssl

to extract the root certificate when you connect to the database server. The following OpenSSL command connects to the PostgreSQL server and writes the certificate chain to a file:

shell
   openssl s_client -showcerts -connect <hostname>:<port> </dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > root.crt

Replace

<hostname>

with your PostgreSQL server hostname and

<port>

with the port (usually 5432). 3. Azure documentation: - Azure may have specific instructions or a downloadable root certificate in their documentation for Postgres services. 4. Ask your Database Administrator (DBA): - If you don’t have direct access, your database administrator may be able to provide you with the

root.crt

. After obtaining the certificate, you can follow the steps I outlined earlier to create a Kubernetes secret with this certificate. Remember that the secret data section must contain the base64 encoded representation of your

root.crt

. Always ensure that you're handling and storing your SSL certificates securely to prevent unauthorized access.

@Marvin I can download the SSL Certificate but it is a .pem file not .crt

A

.pem

file can be used in the same way as a

.crt

file with regards to Kubernetes secrets and SSL certificates. They both represent encoded certificates and the extensions are often used interchangeably. If you have a

.pem

file and you need to create a Kubernetes secret for your SSL certificate, you can use the

.pem

file directly without any conversion. To create the secret, follow these steps: 1. Base64 encode your

.pem

file:

shell
cat your_certificate.pem | base64

2. Replace

BASE64ENCODECERTIFICATE=

with the output from the command above in your secret definition file

db-ssl-secret.yaml

. Here's the updated secret definition using the

.pem

file:

yaml
apiVersion: v1
kind: Secret
metadata:
  name: db-ssl-secret
data:
  root.crt: <base64-encoded-certificate>
type: Opaque

In the

data

dictionary, the key

root.crt

doesn't have to change to match the

.pem

extension; it’s just a name for the key within the secret. 3. Apply the secret to your Kubernetes cluster:

shell
kubectl apply -f db-ssl-secret.yaml

Remember to replace

<base64-encoded-certificate>

with the actual encoded content of your

.pem

file. The steps to apply the secret to the cluster and the handling of the secret within your deployments remain the same regardless of the file extension.

@Marvin I get this error in the prefect-server logs? ssl.SSLError: [X509: NO_CERTIFICATE_OR_CRL_FOUND] no certificate or crl found (_ssl.c:4149)

The error

ssl.SSLError: [X509: NO_CERTIFICATE_OR_CRL_FOUND] no certificate or crl found

suggests that the certificate information was not found where it was expected, or it was not properly loaded. This could happen for several reasons: 1. The Kubernetes secret might not be properly mounted into the Prefect Server pods. 2. The path to the certificate in the Prefect Server configuration might be incorrect. 3. The certificate file itself could be improperly encoded or corrupted in the secret. Here are some steps to troubleshoot and resolve the issue: - Ensure Secret is Correctly Mounted: Check that the secret containing your SSL certificate is correctly mounted into the Prefect Server pods. You can verify the secret's existence in the correct namespace with

kubectl get secrets

and describe it with

kubectl describe secret db-ssl-secret

to ensure it's properly configured. - Verify Certificate Encoding: Double-check the base64 encoding of the certificate. Make sure there are no line breaks or additional characters, and that you encoded the contents of the file, not the filename itself. - Prefect Configuration: Ensure that the Prefect Server configuration or environment variables correctly point to the path of the mounted certificate. If you're using environment variables to configure the SSL setup for Prefect Server, ensure they are named correctly and have the correct values. - Certificate File Name: If you changed the name of the certificate file in the secret (e.g., from

root.crt

to

root.pem

), make sure that the Prefect Server configuration reflects this change. - Check Certificate Validity: Verify the certificate's validity by using OpenSSL or another tool to check that the certificate is not expired and is correctly formed. If the issue persists after checking these points and correcting any problems, it may be helpful to check the Prefect community channels or raise an issue with specific details on the Prefect GitHub repository. Since the tool did not find any similar issues on GitHub, this might be a unique setup issue or a less commonly encountered problem.

@Marvin I have encoded the pem file and applied to secret? Now the prefect-server pod has the error: OSError: Multiple exceptions: [Errno 111] Connect call failed ('127.0.0.1', 5432), [Errno 99] Cannot assign requested address

The error you're encountering,

OSError: Multiple exceptions: [Errno 111] Connect call failed ('127.0.0.1', 5432), [Errno 99] Cannot assign requested address

, suggests that Prefect Server is trying to connect to a database on the local machine (

127.0.0.1

), but it's either not running there, or something is misconfigured. Here are some possible reasons and solutions to consider: 1. PostgreSQL Server Location: Verify that you are not mistakenly trying to connect to a local PostgreSQL server and that your database URL is indeed pointing to your external Azure PostgreSQL instance, not the loopback address (

127.0.0.1

). 2. Check Database URL: Ensure that the

PREFECT_API_DATABASE_CONNECTION_URL

environment variable correctly specifies the fully qualified domain name (FQDN) or IP address of your Azure PostgreSQL server, not

localhost

or

127.0.0.1

. 3. Kubernetes Network Configuration: The

[Errno 99] Cannot assign requested address

error can occur if there's a network configuration issue within your Kubernetes setup that's preventing the Prefect Server pod from connecting to the database server. 4. Database Port Availability: Ensure that the database port (default

5432

for PostgreSQL) is open and accessible from within your Kubernetes cluster. Network policies, firewalls, or other security configurations may be blocking access. 5. Database Credentials and SSL: Double-check that your database credentials are correct and that if SSL is required for your Azure PostgreSQL connection, it is properly configured, and the Kubernetes secret for the SSL certificate is correctly mounted and used in your Prefect Server deployment. 6. Kubernetes Secret Configuration: Ensure that any SSL-related environment variables and volume mounts are correctly configured in your Prefect Server helm chart values to reflect the use of your Kubernetes secret

db-ssl-secret

. A similar issue on GitHub was found: Cannot start Orion `FastAPI` app: `Cannot assign requested address`. While the context may be different, it might be helpful to check if there are any network-related similarities in your Kubernetes environment. You would need to review and correct your configuration to point to the correct database host and ensure all network connections are properly established. If the issue persists after these checks, further investigation on the Prefect Server's configuration or Kubernetes network settings may be necessary.

@Marvin how to create this secret?

## This secret must contain two key-value pairs where the first key is `connection-string` and the value is the
    ## connection string containing your password (e.g. postgresql+asyncpg://{username}:{password}@{hostname}/{database}).
    ## The second key-value pair has the key `password` and the value is the {password} used in the connection string

existingSecret: ""

To create a Kubernetes secret that contains the specified key-value pairs for

connection-string

and

password

, follow these steps: 1. Construct the connection string: Prepare the connection string with the necessary details, like your username, password, hostname, and database name, following the template given:

plaintext
   postgresql+asyncpg://{username}:{password}@{hostname}/{database}

2. Base64 encode your connection-string and password: - For the connection string:

shell
   echo -n 'postgresql+asyncpg://{username}:{password}@{hostname}/{database}' | base64

Replace

{username}

,

{password}

,

{hostname}

, and

{database}

with your actual database connection details. - For the password:

shell
   echo -n '{password}' | base64

Replace

{password}

with your actual database password. 3. Create the secret manually or via YAML file: - To create the secret manually, use the

kubectl create secret

command:

shell
   kubectl create secret generic db-secret --from-literal=connection-string='base64-encoded-connection-string' --from-literal=password='base64-encoded-password'

Replace

base64-encoded-connection-string

and

base64-encoded-password

with the encoded values obtained from the previous step. - To create the secret via a YAML file, define your secret in the following format and save this to a file like `db-secret.yaml`:

yaml
   apiVersion: v1
   kind: Secret
   metadata:
     name: db-secret
   data:
     connection-string: <base64-encoded-connection-string>
     password: <base64-encoded-password>
   type: Opaque

Again, replace

<base64-encoded-connection-string>

and

<base64-encoded-password>

with your actual base64 encoded values. 4. Apply the secret: After creating the

db-secret.yaml

file, apply it with:

shell
   kubectl apply -f db-secret.yaml

This will create a Secret called

db-secret

with the

connection-string

and

password

data required. You can then reference

db-secret

in the

existingSecret

parameter of your Prefect Server Helm chart or any other Kubernetes resource that needs to access these secrets.

@Marvin I'm getting this error. CreateContainerConfigError

A

CreateContainerConfigError

in Kubernetes can occur for several reasons, such as: 1. Secrets and ConfigMaps Not Found: If your container configuration references a Kubernetes secret or ConfigMap that does not exist, Kubernetes will not be able to create the container configuration. 2. Invalid Secret Keys: If your secret is expected to contain specific keys (as in the

connection-string

and

password

case), but those keys are missing or misspelled, the error can occur. 3. Incorrect Image Name: If your pod spec has an incorrect image name or tag, or if the image is in a registry that requires credentials that are not provided, then the pod cannot start. 4. Resource Limits: If the resource limits specified are not sufficient for the container or are not available in the cluster, it might cause this error. To resolve the issue, here's what you can do: - Check Events: Look at the Kubernetes events for the pod to get more information about why the container configuration is failing. This can be done with the command:

kubectl describe pod <pod-name>

- Examine Secret: Make sure that the secret you created (

db-secret

) exists, has the correct name, and includes the expected

connection-string

and

password

keys. - Image Pull Issues: Ensure that the image you are trying to pull exists and that any image pull secrets are correctly configured if required. - Resource Requirements: Review the resource requirements for the Prefect Server container and ensure that they match the available resources in your Kubernetes cluster. - Inspect Pod Spec: Review the pod specification to make sure all references to configs, secrets, and images are correct. Addressing these points should help you identify and fix the source of the

CreateContainerConfigError

. If the error persists after checking these, it might be necessary to get more context or examine other configurations related to the Kubernetes deployment.

@Marvin prefect server: OSError: Multiple exceptions: [Errno 111] Connect call failed ('127.0.0.1', 5432), [Errno 99] Cannot assign requested address

The error message you're seeing indicates that Prefect Server is trying to connect to a database at localhost (

127.0.0.1

) on port

5432

(the default port for PostgreSQL), but it's failing for some reason. The

[Errno 111] Connect call failed ('127.0.0.1', 5432)

part of the error suggests that Prefect Server cannot establish a connection to the database because there's no database server listening on

localhost:5432

. This could happen if the Prefect Server is configured to connect to a local database that isn't running or if the connection configuration is incorrect. The

[Errno 99] Cannot assign requested address

part of the error often suggests a network issue within the container or the host it's running on. It could mean that the Prefect Server cannot bind to the requested network address or port, which might happen if the address/port is not available within the container's network namespace or the host. Here are some steps to resolve common issues related to this error: 1. Check Database Connection Configuration: Ensure that the

PREFECT_API_DATABASE_CONNECTION_URL

environment variable is set to the correct connection string pointing to the Azure PostgreSQL server, not

localhost

or

127.0.0.1

. 2. Database Reachability: Confirm that your Azure PostgreSQL server is actually reachable from within your Kubernetes environment and that all firewalls or network security groups are allowing traffic on the relevant port (normally

5432

for PostgreSQL). 3. Secrets and Environment Variables: If you're using a Kubernetes secret to hold the database connection string, verify that it's correctly referenced in the Prefect Server deployment configuration and that environment variables are set accordingly. 4. Inspect Prefect Server Deployment: Verify that the Prefect Server deployment YAML is correct and that the database connection string is not defaulting to

localhost

. If necessary, update it to point to the correct database address. 5. Resource Conflicts: Make sure there's no conflict with any other services trying to bind to the same port within your Kubernetes cluster. This can happen if other services are incorrectly configured or if there are port forwarding issues. 6. Logging: Increase the logging level in Prefect Server to get more details about the connection attempts and see where they might be going wrong. If after reviewing these items you're still experiencing the issue, consider gathering more detailed logs from the Prefect Server pod and checking within the Kubernetes cluster networking configurations for anything that could be causing the assignment address issue.

@Marvin After "describe pod" Environment: HOME: /home/prefect PREFECT_API_URL: http://localhost:4200/api PREFECT_DEBUG_MODE: false PREFECT_LOGGING_SERVER_LEVEL: WARNING PREFECT_SERVER_API_HOST: 0.0.0.0 PREFECT_SERVER_API_PORT: 4200 PREFECT_UI_ENABLED: true PREFECT_UI_STATIC_DIRECTORY: /ui_build PREFECT_API_DATABASE_CONNECTION_URL: <set to the key 'connection-string' in secret 'prefect-postgres-secret'> Optional: false

The environment variable

PREFECT_API_DATABASE_CONNECTION_URL

is set to reference a key in the

prefect-postgres-secret

Kubernetes secret. However, the Prefect Server is still attempting to connect to

localhost:4200/api

, which is likely a misconfiguration. The

PREFECT_API_URL

environment variable should not point to

localhost

if the server needs to use an external database. Instead, it should be set to the internal or external service endpoint where the Prefect API is reachable within your Kubernetes environment. Here's what you should check and possibly correct: 1. Database Connection URL: Review the

prefect-postgres-secret

Kubernetes secret to ensure that the

connection-string

key exists and contains the correct connection string to your external Azure Postgres server. 2. PREFECT_API_URL: The

PREFECT_API_URL

environment variable should likely be set to the internal service name for the Prefect API within Kubernetes, for example,

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

or whatever the correct internal DNS name and port number that your Prefect Server's API service is available at. 3. Database Configuration: In the Prefect Server deployment configuration, confirm that the

PREFECT_API_DATABASE_CONNECTION_URL

environment variable is properly referencing the secret and that the secret's

connection-string

is the correct Azure Postgres connection string. 4. Secret Referencing: Make sure that the way you are referencing the secret key is correct in the Kubernetes Deployment YAML. For example:

yaml
env:
  - name: PREFECT_API_DATABASE_CONNECTION_URL
    valueFrom:
      secretKeyRef:
        name: prefect-postgres-secret
        key: connection-string

5. Restart Prefect Server: After correcting the configuration, you might need to restart Prefect Server for the changes to take effect. You can do this by deleting the existing Pod so that Kubernetes will recreate it with the updated configuration:

sh
kubectl delete pod <prefect-server-pod-name>

6. Deployment Inspection: Check the Prefect Server deployment again to confirm that the environment variables are now set correctly. By updating these configurations, you should be able to rectify the incorrect

localhost

connection attempt and ensure that Prefect Server is using the correct database connection information from

prefect-postgres-secret

.

@Marvin do I need to change "prefectApiUrl" to sue external postgres

No, you generally do not need to change the

PREFECT_API_URL

environment variable to use an external PostgreSQL database. This variable is used to specify the location of the Prefect API for clients and the UI to connect to, not the location of the database. The

PREFECT_API_DATABASE_CONNECTION_URL

is the critical environment variable that needs to be set correctly to point to your external PostgreSQL instance. This variable should contain the full database connection string that allows Prefect Server to connect to the external PostgreSQL database. Here's what you should typically configure for an external PostgreSQL instance: 1. PREFECT_API_DATABASE_CONNECTION_URL: This should be set with the connection string to your external PostgreSQL database. It follows this format:

postgresql+asyncpg://<username>:<password>@<hostname>:<port>/<database>

Ensure that you replace

<username>

,

<password>

,

<hostname>

,

<port>

, and

<database>

with the actual credentials and details of your PostgreSQL instance. This environment variable can be set in your Kubernetes deployment using a

secretKeyRef

if you stored the information in a Kubernetes secret. 2. PREFECT_API_URL: This should remain pointing to the Prefect API service endpoint within your Kubernetes cluster if Prefect Server and the Prefect API are deployed within the same cluster. Clients and the UI use this URL to make requests to the Prefect API. It typically does not need to be changed unless you have set up an ingress or some other form of external access to the Prefect Server API. Remember that environment variables can be set directly or referenced from Kubernetes secrets in your deployment manifests. Here's an example snippet that sets the

PREFECT_API_DATABASE_CONNECTION_URL

from a secret:

yaml
env:
  - name: PREFECT_API_DATABASE_CONNECTION_URL
    valueFrom:
      secretKeyRef:
        name: prefect-postgres-secret
        key: connection-string

Ensure to apply the configuration changes to your Prefect Server deployment for them to take effect.