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<@ULVA73B9P> how do i inject k8 secret into env va...
# ask-marvin
y
@Marvin how do i inject k8 secret into env var to be consumed by prefect worker?
m
To inject a Kubernetes secret into an environment variable for a Prefect worker, you can use the 
valueFrom
field in your Kubernetes job configuration. Here's a basic example from the documentation:
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yaml
work_pool:
  name: kubernetes-prd-internal-tools
  job_variables:
    env:
      - name: MYENVFROM
        valueFrom:
          secretKeyRef:
            name: "your-secret-name"
            key: "your-secret-key"
In this configuration, 
MYENVFROM
will be populated with the value from the specified Kubernetes secret. You will need to ensure that your Kubernetes environment has access to the secret and that it is properly configured. For more detailed guidance, you can refer to the Prefect Kubernetes deployment examples. Additionally, you can also use Helm to manage Prefect workers in Kubernetes, as shown in this example. It includes instructions for creating a Kubernetes secret and deploying a Prefect worker using Helm.
y
@Marvin how do i do it in the base job template
m
To inject a Kubernetes secret into an environment variable using the base job template in Prefect, you can modify the 
job_configuration
section of the base job template. Here's a basic outline of how you can do it: 1. Access the Base Job Template: You can modify the base job template through the Prefect UI or by editing the JSON configuration directly. 2. Edit the 
job_configuration
Section: In the 
job_configuration
, you can specify environment variables and use 
valueFrom
to reference Kubernetes secrets. Here's a JSON example to guide you:
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json
{
  "job_configuration": {
    "template": {
      "spec": {
        "containers": [
          {
            "name": "your-container-name",
            "env": [
              {
                "name": "MYENVFROM",
                "valueFrom": {
                  "secretKeyRef": {
                    "name": "your-secret-name",
                    "key": "your-secret-key"
                  }
                }
              }
            ]
          }
        ]
      }
    }
  }
}
3. Variables Section: The 
variables
section of the base job template allows you to define fields that can be customized per deployment or flow run. You can use placeholders in the 
job_configuration
to reference these variables. For further details, you can refer to the Prefect documentation on infrastructure concepts.
y
@Marvin can i have job template in yaml file format?
m
The Prefect documentation primarily references the base job template in JSON format, particularly when discussing the configuration of work pools and jobs. However, you can certainly define your job configuration in YAML format for easier readability and conversion to JSON if needed. Here's an example of how you might structure a base job template in YAML:
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yaml
job_configuration:
  template:
    spec:
      containers:
        - name: your-container-name
          env:
            - name: MYENVFROM
              valueFrom:
                secretKeyRef:
                  name: your-secret-name
                  key: your-secret-key
To use this YAML configuration in Prefect, you would typically convert it to JSON, as JSON is the expected format for the base job template in Prefect's configuration. For more details on configuring work pools and base job templates, you can refer to the Prefect documentation on work pools.
y
@Marvin how can i specify a environment variable placeholder in the job template
m
To specify an environment variable placeholder in a Prefect job template, you can use double curly braces to declare placeholders. These placeholders can reference values provided in the 
variables
section of the base job template. Here's how you can do it: 1. Define Variables: In the 
variables
section of your base job template, define the fields that can be customized. 2. Use Placeholders: In the 
job_configuration
section, use placeholders to reference these variables. Here's a JSON example illustrating this:
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json
{
  "variables": {
    "MY_VARIABLE": {
      "type": "string",
      "default": "default_value"
    }
  },
  "job_configuration": {
    "template": {
      "spec": {
        "containers": [
          {
            "name": "your-container-name",
            "env": [
              {
                "name": "MY_ENV_VAR",
                "value": "{{ MY_VARIABLE }}"
              }
            ]
          }
        ]
      }
    }
  }
}
In this example, 
{{ MY_VARIABLE }}
is a placeholder in the 
job_configuration
that will be replaced with the value specified in the 
variables
section or overridden at deployment time. For more information, you can refer to the Prefect documentation on work pools and job templates.
y
@Marvin how can i overwrite the placeholder at deployment time?
m
To overwrite placeholders at deployment time in Prefect, you can specify job variables in your deployment configuration. This can be done using the 
prefect.yaml
file or by passing variables directly through the CLI or API. Here’s how you can do it using the 
prefect.yaml
file: 1. Define Job Variables in 
prefect.yaml
: Add a 
job_variables
section to your deployment definition to specify the values you want to override.
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yaml
deployments:
  - name: demo-deployment
    job_variables:
      MY_VARIABLE: "new_value"
2. Deploy with Overridden Variables: Run the deployment using the Prefect CLI, and the specified variables will override the defaults in your base job template.
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bash
prefect deploy -n demo-deployment
3. Using the CLI Directly: You can also pass job variables directly via the CLI using the 
-jv
or 
--job-variable
flag.
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bash
prefect deploy -n demo-deployment --job-variable MY_VARIABLE=new_value
These methods allow you to customize the environment for each deployment, ensuring that placeholders in the job template are replaced with the specified values. For more details, check the Prefect documentation on customizing deployments.
y
@Marvin i want to automate the update of image in my cicd pipeline. How can i overwrite the image during cicd in job template
m
To automate the update of an image in your CI/CD pipeline for a Prefect deployment, you can overwrite the image in the job template using variables and automation. Here's a general approach you can follow: 1. Use Placeholders in Job Template: Define a placeholder for the image in your job template. For example:
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yaml
   job_configuration:
     template:
       spec:
         containers:
           - name: your-container-name
             image: "{{ IMAGE_NAME }}"
2. Set Up CI/CD Pipeline: In your CI/CD pipeline, dynamically set the 
IMAGE_NAME
variable to the new image tag/version. You can do this by updating the 
prefect.yaml
file or passing it directly through the CLI. 3. Automate Deployment with Prefect CLI: Use the Prefect CLI to deploy with the updated image. You can use the 
--job-variable
flag to overwrite the image placeholder:
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bash
   prefect deploy -n your-deployment --job-variable IMAGE_NAME=new-image:latest
4. Integrate with CI/CD Tools: Ensure your CI/CD tool runs the above command whenever a new image is built. This can be done through scripts or CI/CD platform-specific configuration. 5. Use Prefect Automations: Optionally, you can set up Prefect automations to trigger deployments based on events or schedules, providing flexibility in how and when deployments occur. For more detailed guidance, you may refer to the Prefect documentation on automations and triggers.
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