Use the KubernetesPodOperator

Cloud Composer 3 | Cloud Composer 2 | Cloud Composer 1

This page describes how to use KubernetesPodOperator to deploy Kubernetes Pods from Cloud Composer into the Google Kubernetes Engine cluster that is part of your Cloud Composer environment.

KubernetesPodOperator launches Kubernetes Pods in your environment's cluster. In comparison, Google Kubernetes Engine operators run Kubernetes Pods in a specified cluster, which can be a separate cluster that is not related to your environment. You can also create and delete clusters using Google Kubernetes Engine operators.

KubernetesPodOperator is a good option if you require:

  • Custom Python dependencies that are not available through the public PyPI repository.
  • Binary dependencies that are not available in the stock Cloud Composer worker image.

Before you begin

Check the following list of differences between KubernetesPodOperator in Cloud Composer 3 and Cloud Composer 2 and make sure that your DAGs are compatible:

  • It is not possible to create custom namespaces in Cloud Composer 3. Pods always run in the composer-user-workloads namespace, even if a different namespace is specified. Pods in this namespace have access to your project's resources and VPC network (if enabled) without additional configuration.

  • Kubernetes Secrets and ConfigMaps can't be created using Kubernetes API. Instead, Cloud Composer provides Google Cloud CLI commands, Terraform resources, and Cloud Composer API to manage Kubernetes Secrets and ConfigMaps. For more information, see Use Kubernetes Secrets and ConfigMaps.

  • It isn't possible to deploy custom workloads in Cloud Composer 3. Only Kubernetes Secrets and ConfigMaps can be modified, but all other configuration changes aren't possible.

  • Resource requirements (CPU, memory, and storage) must be specified using supported values.

  • Same as in Cloud Composer 2, Pod affinity configuration is not available. If you want to use Pod affinity, use the GKE operators to launch Pods in a different cluster instead.

About KubernetesPodOperator in Cloud Composer 3

This section describes how KubernetesPodOperator works in Cloud Composer 3.

Resource usage

In Cloud Composer 3, your environment's cluster scales automatically. Extra workloads that you run using KubernetesPodOperator scale independently from your environment. Your environment is not affected by the increased resource demand, but your environment's cluster scales up and down depending on the resource demand.

The pricing for the extra workloads that you run in your environment's cluster follows the Cloud Composer 3 pricing model and uses Cloud Composer 3 SKUs.

Cloud Composer 3 uses Autopilot clusters which introduce the notion of compute classes:

  • Cloud Composer supports only the general-purpose compute class.

  • By default, if no class is selected then the general-purpose class is assumed when you create Pods using KubernetesPodOperator.

  • Each class is associated with specific properties and resource limits, You can read about them in Autopilot documentation. For example, Pods that run within the general-purpose class can use up to 110 GiB of memory.

Access to project's resources

In Cloud Composer 3, your environment's cluster is located in the tenant project, Pods are executed in the environment's cluster, in an isolated namespace.

In Cloud Composer 3, Pods always run in the composer-user-workloads namespace, even if a different namespace is specified. Pods in this namespace can access Google Cloud resources in your project and your VPC network (if it's enabled) without additional configuration. Your environment's service account is used to access these resources. It is not possible to specify a different service account.

Minimal configuration

To create a KubernetesPodOperator, only Pod's name, image to use, and task_id parameters are required. The /home/airflow/composer_kube_config contains credentials to authenticate to GKE.

kubernetes_min_pod = KubernetesPodOperator(
    # The ID specified for the task.
    task_id="pod-ex-minimum",
    # Name of task you want to run, used to generate Pod ID.
    name="pod-ex-minimum",
    # Entrypoint of the container, if not specified the Docker container's
    # entrypoint is used. The cmds parameter is templated.
    cmds=["echo"],
    # The namespace to run within Kubernetes. In Composer 2 environments
    # after December 2022, the default namespace is
    # `composer-user-workloads`. Always use the
    # `composer-user-workloads` namespace with Composer 3.
    namespace="composer-user-workloads",
    # Docker image specified. Defaults to hub.docker.com, but any fully
    # qualified URLs will point to a custom repository. Supports private
    # gcr.io images if the Composer Environment is under the same
    # project-id as the gcr.io images and the service account that Composer
    # uses has permission to access the Google Container Registry
    # (the default service account has permission)
    image="gcr.io/gcp-runtimes/ubuntu_20_0_4",
    # Specifies path to kubernetes config. The config_file is templated.
    config_file="/home/airflow/composer_kube_config",
    # Identifier of connection that should be used
    kubernetes_conn_id="kubernetes_default",
)

Additional configuration

This example shows additional parameters that you can configure in the KubernetesPodOperator.

See the following resources for more information:

kubernetes_full_pod = KubernetesPodOperator(
    task_id="ex-all-configs",
    name="pi",
    namespace="composer-user-workloads",
    image="perl:5.34.0",
    # Entrypoint of the container, if not specified the Docker container's
    # entrypoint is used. The cmds parameter is templated.
    cmds=["perl"],
    # Arguments to the entrypoint. The Docker image's CMD is used if this
    # is not provided. The arguments parameter is templated.
    arguments=["-Mbignum=bpi", "-wle", "print bpi(2000)"],
    # The secrets to pass to Pod, the Pod will fail to create if the
    # secrets you specify in a Secret object do not exist in Kubernetes.
    secrets=[],
    # Labels to apply to the Pod.
    labels={"pod-label": "label-name"},
    # Timeout to start up the Pod, default is 600.
    startup_timeout_seconds=600,
    # The environment variables to be initialized in the container.
    # The env_vars parameter is templated.
    env_vars={"EXAMPLE_VAR": "/example/value"},
    # If true, logs stdout output of container. Defaults to True.
    get_logs=True,
    # Determines when to pull a fresh image, if 'IfNotPresent' will cause
    # the Kubelet to skip pulling an image if it already exists. If you
    # want to always pull a new image, set it to 'Always'.
    image_pull_policy="Always",
    # Annotations are non-identifying metadata you can attach to the Pod.
    # Can be a large range of data, and can include characters that are not
    # permitted by labels.
    annotations={"key1": "value1"},
    # Optional resource specifications for Pod, this will allow you to
    # set both cpu and memory limits and requirements.
    # Prior to Airflow 2.3 and the cncf providers package 5.0.0
    # resources were passed as a dictionary. This change was made in
    # https://github.com/apache/airflow/pull/27197
    # Additionally, "memory" and "cpu" were previously named
    # "limit_memory" and "limit_cpu"
    # resources={'limit_memory': "250M", 'limit_cpu': "100m"},
    container_resources=k8s_models.V1ResourceRequirements(
        requests={"cpu": "1000m", "memory": "10G", "ephemeral-storage": "10G"},
        limits={"cpu": "1000m", "memory": "10G", "ephemeral-storage": "10G"},
    ),
    # Specifies path to kubernetes config. The config_file is templated.
    config_file="/home/airflow/composer_kube_config",
    # If true, the content of /airflow/xcom/return.json from container will
    # also be pushed to an XCom when the container ends.
    do_xcom_push=False,
    # List of Volume objects to pass to the Pod.
    volumes=[],
    # List of VolumeMount objects to pass to the Pod.
    volume_mounts=[],
    # Identifier of connection that should be used
    kubernetes_conn_id="kubernetes_default",
    # Affinity determines which nodes the Pod can run on based on the
    # config. For more information see:
    # https://kubernetes.io/docs/concepts/configuration/assign-pod-node/
    # Pod affinity with the KubernetesPodOperator
    # is not supported with Composer 2
    # instead, create a cluster and use the GKEStartPodOperator
    # https://cloud.google.com/composer/docs/using-gke-operator
    affinity={},
)

Use Jinja templates

Airflow supports Jinja templates in DAGs.

You must declare the required Airflow parameters (task_id, name, and image) with the operator. As shown in the following example, you can template all other parameters with Jinja, including cmds, arguments, env_vars, and config_file.

The env_vars parameter in the example is set from an Airflow variable named my_value. The example DAG gets its value from the vars template variable in Airflow. Airflow has more variables that provide access to different types of information. For example, you can use the conf template variable to access values of Airflow configuration options. For more information and the list of variables available in Airflow, see Templates reference in the Airflow documentation.

Without changing the DAG or creating the env_vars variable, the ex-kube-templates task in the example fails because the variable does not exist. Create this variable in the Airflow UI or with Google Cloud CLI:

Airflow UI

  1. Go to the Airflow UI.

  2. In the toolbar, select Admin > Variables.

  3. On the List Variable page, click Add a new record.

  4. On the Add Variable page, enter the following information:

    • Key:my_value
    • Val: example_value

  5. Click Save.

gcloud

Enter the following command:

gcloud composer environments run ENVIRONMENT \
    --location LOCATION \
    variables set -- \
    my_value example_value

Replace:

  • ENVIRONMENT with the name of the environment.
  • LOCATION with the region where the environment is located.

The following example demonstrates how to use Jinja templates with KubernetesPodOperator:

kubernetes_template_ex = KubernetesPodOperator(
    task_id="ex-kube-templates",
    name="ex-kube-templates",
    namespace="composer-user-workloads",
    image="bash",
    # All parameters below can be templated with Jinja. For more information
    # and the list of variables available in Airflow, see
    # the Airflow templates reference:
    # https://airflow.apache.org/docs/apache-airflow/stable/templates-ref.html
    # Entrypoint of the container, if not specified the Docker container's
    # entrypoint is used. The cmds parameter is templated.
    cmds=["echo"],
    # DS in Jinja is the execution date as YYYY-MM-DD, this Docker image
    # will echo the execution date. Arguments to the entrypoint. The Docker
    # image's CMD is used if this is not provided. The arguments parameter
    # is templated.
    arguments=["{{ ds }}"],
    # The var template variable allows you to access variables defined in
    # Airflow UI. In this case we are getting the value of my_value and
    # setting the environment variable `MY_VALUE`. The pod will fail if
    # `my_value` is not set in the Airflow UI. The env_vars parameter
    # is templated.
    env_vars={"MY_VALUE": "{{ var.value.my_value }}"},
    # Specifies path to Kubernetes config. The config_file is templated.
    config_file="/home/airflow/composer_kube_config",
    # Identifier of connection that should be used
    kubernetes_conn_id="kubernetes_default",
)

Use Kubernetes Secrets and ConfigMaps

A Kubernetes Secret is an object that contains sensitive data. A Kubernetes ConfigMap is an object that contains non-confidential data in key-value pairs.

In Cloud Composer 3, you can create Secrets and ConfigMaps using Google Cloud CLI, API, or Terraform, and then access them from KubernetesPodOperator:

  • With Google Cloud CLI and API, you provide a YAML configuration file.
  • With Terraform, you define Secrets and ConfigMaps as separate resources in Terraform configuration files.

About YAML configuration files

When you create a Kubernetes Secret or a ConfigMap using Google Cloud CLI and API, you provide a file in the YAML format. This file must follow the same format as used by Kubernetes Secrets and ConfigMaps. Kubernetes documentation provides many code samples of ConfigMaps and Secrets. To get started, you can see the Distribute Credentials Securely Using Secrets page and ConfigMaps.

Same as in Kubernetes Secrets, use the base64 representation when you define values in Secrets.

To encode a value, you can use the following command (this is one of many ways to get a base64-encoded value):

echo "postgresql+psycopg2://root:example-password@127.0.0.1:3306/example-db" -n | base64

Output:

cG9zdGdyZXNxbCtwc3ljb3BnMjovL3Jvb3Q6ZXhhbXBsZS1wYXNzd29yZEAxMjcuMC4wLjE6MzMwNi9leGFtcGxlLWRiIC1uCg==

The following two YAML file examples are used in samples later in this guide. Example YAML config file for a Kubernetes Secret:

apiVersion: v1
kind: Secret
metadata:
  name: airflow-secrets
data:
  sql_alchemy_conn: cG9zdGdyZXNxbCtwc3ljb3BnMjovL3Jvb3Q6ZXhhbXBsZS1wYXNzd29yZEAxMjcuMC4wLjE6MzMwNi9leGFtcGxlLWRiIC1uCg==

Another example that demonstrates how to include files. Same as in the previous example, first encode the contents of a file (cat ./key.json | base64), then provide this value in the YAML file:

apiVersion: v1
kind: Secret
metadata:
  name: service-account
data:
  service-account.json: |
    ewogICJ0eXBl...mdzZXJ2aWNlYWNjb3VudC5jb20iCn0K

An example YAML config file for a ConfigMap. You don't need to use the base64 representation in ConfigMaps:

apiVersion: v1
kind: ConfigMap
metadata:
  name: example-configmap
data:
  example_key: example_value

Manage Kubernetes Secrets

gcloud

Create a Secret

To create a Kubernetes Secret, run the following command:

gcloud beta composer environments user-workloads-secrets create \
  --environment ENVIRONMENT_NAME \
  --location LOCATION \
  --secret-file-path SECRET_FILE

Replace the following:

  • ENVIRONMENT_NAME: the name of your environment.
  • LOCATION: the region where the environment is located.
  • SECRET_FILE: path to a local YAML file that contains the Secret's configuration.

Example:

gcloud beta composer environments user-workloads-secrets create \
  --environment example-environment \
  --location us-central1 \
  --secret-file-path ./secrets/example-secret.yaml

Update a Secret

To update a Kubernetes Secret, run the following command. Secret's name will be taken from from the specified YAML file and Secret's contents will be replaced.

gcloud beta composer environments user-workloads-secrets update \
  --environment ENVIRONMENT_NAME \
  --location LOCATION \
  --secret-file-path SECRET_FILE

Replace the following:

  • ENVIRONMENT_NAME: the name of your environment.
  • LOCATION: the region where the environment is located.
  • SECRET_FILE: path to a local YAML file that contains the Secret's configuration. Specify the Secret's name in the metadata > name field in this file.

List Secrets

To get a list of Secrets and their fields for an environment, run the following command. Key values in the output will be replaced with asterisks.

gcloud beta composer environments user-workloads-secrets list \
  --environment ENVIRONMENT_NAME \
  --location LOCATION

Replace the following:

  • ENVIRONMENT_NAME: the name of your environment.
  • LOCATION: the region where the environment is located.

Get Secret's details

To get detailed information about a Secret, run the following command. Key values in the output will be replaced with asterisks.

gcloud beta composer environments user-workloads-secrets describe \
  SECRET_NAME \
  --environment ENVIRONMENT_NAME \
  --location LOCATION

Replace the following:

  • SECRET_NAME: the name of the Secret, as it was defined in the metadata > name field in the YAML file with the Secret's configuration.
  • ENVIRONMENT_NAME: the name of your environment.
  • LOCATION: the region where the environment is located.

Delete a Secret

To delete a Secret, run the following command:

gcloud beta composer environments user-workloads-secrets delete \
  SECRET_NAME \
  --environment ENVIRONMENT_NAME \
  --location LOCATION
  • SECRET_NAME: the name of the Secret, as it was defined in the metadata > name field in the YAML file with the Secret's configuration.
  • ENVIRONMENT_NAME: the name of your environment.
  • LOCATION: the region where the environment is located.

API

Create a Secret

  1. Create an environments.userWorkloadsSecrets.create API request.

  2. In this request:

    1. In the request body, in the name field, specify the URI for the new Secret.
    2. In the request body, in the data field, specify keys and base64-encoded values for the Secret.

Example:

// POST https://composer.googleapis.com/v1beta1/projects/example-project/
// locations/us-central1/environments/example-environment/userWorkloadsSecrets

{
  "name": "projects/example-project/locations/us-central1/environments/example-environment/userWorkloadsSecrets/example-secret",
  "data": {
    "example": "ZXhhbXBsZV92YWx1ZSAtbgo="
  }
}

Update a Secret

  1. Create an environments.userWorkloadsSecrets.update API request.

  2. In this request:

    1. In the request body, in the name field, specify the URI of the Secret.
    2. In the request body, in the data field, specify keys and base64-encoded values for the Secret. The values will be replaced.

Example:

// PUT https://composer.googleapis.com/v1beta1/projects/example-project/
// locations/us-central1/environments/example-environment/userWorkloadsSecrets/example-secret

{
  "name": "projects/example-project/locations/us-central1/environments/example-environment/userWorkloadsSecrets/example-secret",
  "data": {
    "example": "ZXhhbXBsZV92YWx1ZSAtbgo=",
    "another-example": "YW5vdGhlcl9leGFtcGxlX3ZhbHVlIC1uCg=="
  }
}

List Secrets

Create an environments.userWorkloadsSecrets.list API request. Key values in the output will be replaced with asterisks. It's possible to use pagination with this request, see the request's reference for more details.

Example:

// GET https://composer.googleapis.com/v1beta1/projects/example-project/
// locations/us-central1/environments/example-environment/userWorkloadsSecrets

Get Secret's details

Create an environments.userWorkloadsSecrets.get API request. Key values in the output will be replaced with asterisks.

Example:

// GET https://composer.googleapis.com/v1beta1/projects/example-project/
// locations/us-central1/environments/example-environment/userWorkloadsSecrets/example-secret

Delete a Secret

Create an environments.userWorkloadsSecrets.delete API request.

Example:

// DELETE https://composer.googleapis.com/v1beta1/projects/example-project/
// locations/us-central1/environments/example-environment/userWorkloadsSecrets/example-secret

Terraform

The google_composer_user_workloads_secret resource defines a Kubernetes Secret, with keys and values defined in the data block.

resource "google_composer_user_workloads_secret" "example_secret" {
  provider = google-beta
  environment = google_composer_environment.ENVIRONMENT_RESOURCE_NAME.name
  name = "SECRET_NAME"
  region = "LOCATION"

  data = {
    KEY_NAME: "KEY_VALUE"
  }
}
  • ENVIRONMENT_RESOURCE_NAME: the name of the environment's resource, which contains the definition of the environment in Terraform. The actual environment's name is also specified in this resource.
  • LOCATION: the region where the environment is located.
  • SECRET_NAME: the name of the Secret.
  • KEY_NAME: one or more keys for this Secret.
  • KEY_VALUE: base64-encoded value for the key. You can use the base64encode function to encode the value (see the example).

The following two examples of Kubernetes Secrets are used in samples later in this guide.

resource "google_composer_user_workloads_secret" "example_secret" {
  provider = google-beta

  name = "airflow-secrets"

  environment = google_composer_environment.example_environment.name
  region = "us-central1"

  data = {
    sql_alchemy_conn: base64encode("postgresql+psycopg2://root:example-password@127.0.0.1:3306/example-db")
  }
}

Another example that demonstrates how to include files. You can use the file function to read file's contents as a string, and then base64-encode it:

resource "google_composer_user_workloads_secret" "service_account_secret" {
  provider = google-beta

  name = "service-account"

  environment = google_composer_environment.example_environment.name
  region = "us-central1"

  data = {
    "service-account.json": base64encode(file("./key.json"))
  }
}

Use Kubernetes Secrets in your DAGs

This example shows two ways of using Kubernetes Secrets: as an environment variable, and as a volume mounted by the Pod.

The first Secret, airflow-secrets, is set to a Kubernetes environment variable named SQL_CONN (as opposed to an Airflow or Cloud Composer environment variable).

The second Secret, service-account, mounts service-account.json, a file with a service account token, to /var/secrets/google.

Here's what the Secret objects look like:

secret_env = Secret(
    # Expose the secret as environment variable.
    deploy_type="env",
    # The name of the environment variable, since deploy_type is `env` rather
    # than `volume`.
    deploy_target="SQL_CONN",
    # Name of the Kubernetes Secret
    secret="airflow-secrets",
    # Key of a secret stored in this Secret object
    key="sql_alchemy_conn",
)
secret_volume = Secret(
    deploy_type="volume",
    # Path where we mount the secret as volume
    deploy_target="/var/secrets/google",
    # Name of Kubernetes Secret
    secret="service-account",
    # Key in the form of service account file name
    key="service-account.json",
)

The name of the first Kubernetes Secret is defined in the secret_env variable. This Secret is named airflow-secrets. The deploy_type parameter specifies that it must be exposed as an environment variable. The environment variable's name is SQL_CONN, as specified in the deploy_target parameter. Finally, the value of the SQL_CONN environment variable is set to the value of the sql_alchemy_conn key.

The name of the second Kubernetes Secret is defined in the secret_volume variable. This Secret is named service-account. It is exposed as an volume, as specified in the deploy_type parameter. The path of the file to mount, deploy_target, is /var/secrets/google. Finally, the key of the Secret that is stored in the deploy_target is service-account.json.

Here's what the operator configuration looks like:

kubernetes_secret_vars_ex = KubernetesPodOperator(
    task_id="ex-kube-secrets",
    name="ex-kube-secrets",
    namespace="composer-user-workloads",
    image="gcr.io/gcp-runtimes/ubuntu_20_0_4",
    startup_timeout_seconds=300,
    # The secrets to pass to Pod, the Pod will fail to create if the
    # secrets you specify in a Secret object do not exist in Kubernetes.
    secrets=[secret_env, secret_volume],
    # Entrypoint of the container, if not specified the Docker container's
    # entrypoint is used. The cmds parameter is templated.
    cmds=["echo"],
    # env_vars allows you to specify environment variables for your
    # container to use. The env_vars parameter is templated.
    env_vars={
        "EXAMPLE_VAR": "/example/value",
        "GOOGLE_APPLICATION_CREDENTIALS": "/var/secrets/google/service-account.json",
    },
    # Specifies path to kubernetes config. The config_file is templated.
    config_file="/home/airflow/composer_kube_config",
    # Identifier of connection that should be used
    kubernetes_conn_id="kubernetes_default",
)

Manage Kubernetes ConfigMaps

gcloud

Create a ConfigMap

To create a ConfigMap, run the following command:

gcloud beta composer environments user-workloads-config-maps create \
  --environment ENVIRONMENT_NAME \
  --location LOCATION \
  --config-map-file-path CONFIG_MAP_FILE

Replace the following:

  • ENVIRONMENT_NAME: the name of your environment.
  • LOCATION: the region where the environment is located.
  • CONFIG_MAP_FILE: path to a local YAML file that contains the ConfigMap's configuration.

Example:

gcloud beta composer environments user-workloads-config-maps create \
  --environment example-environment \
  --location us-central1 \
  --config-map-file-path ./configs/example-configmap.yaml

Update a ConfigMap

To update a ConfigMap, run the following command. ConfigMaps's name will be taken from from the specified YAML file and ConfigMap's contents will be replaced.

gcloud beta composer environments user-workloads-config-maps update \
  --environment ENVIRONMENT_NAME \
  --location LOCATION \
  --config-map-file-path CONFIG_MAP_FILE

Replace the following:

  • ENVIRONMENT_NAME: the name of your environment.
  • LOCATION: the region where the environment is located.
  • CONFIG_MAP_FILE: path to a local YAML file that contains the ConfigMap's configuration. Specify the ConfigMap's name in the metadata > name field in this file.

List ConfigMaps

To get a list of ConfigMaps and their fields for an environment, run the following command. Key values in the output will be displayed as is.

gcloud beta composer environments user-workloads-config-maps list \
  --environment ENVIRONMENT_NAME \
  --location LOCATION

Replace the following:

  • ENVIRONMENT_NAME: the name of your environment.
  • LOCATION: the region where the environment is located.

Get ConfigMap's details

To get detailed information about a ConfigMap, run the following command. Key values in the output will be displayed as is.

gcloud beta composer environments user-workloads-config-maps describe \
  CONFIG_MAP_NAME \
  --environment ENVIRONMENT_NAME \
  --location LOCATION

Replace the following:

  • CONFIG_MAP_NAME: the name of the ConfigMap, as it was defined in the metadata > name field in the YAML file with the ConfigMap's configuration.
  • ENVIRONMENT_NAME: the name of your environment.
  • LOCATION: the region where the environment is located.

Delete a ConfigMap

To delete a ConfigMap, run the following command:

gcloud beta composer environments user-workloads-config-maps delete \
  CONFIG_MAP_NAME \
  --environment ENVIRONMENT_NAME \
  --location LOCATION
  • CONFIG_MAP_NAME: the name of the ConfigMap, as it was defined in the metadata > name field in the YAML file with the ConfigMap's configuration.
  • ENVIRONMENT_NAME: the name of your environment.
  • LOCATION: the region where the environment is located.

API

Create a ConfigMap

  1. Create an environments.userWorkloadsConfigMaps.create API request.

  2. In this request:

    1. In the request body, in the name field, specify the URI for the new ConfigMap.
    2. In the request body, in the data field, specify keys and values for the ConfigMap.

Example:

// POST https://composer.googleapis.com/v1beta1/projects/example-project/
// locations/us-central1/environments/example-environment/userWorkloadsConfigMaps

{
  "name": "projects/example-project/locations/us-central1/environments/example-environment/userWorkloadsConfigMaps/example-configmap",
  "data": {
    "example_key": "example_value"
  }
}

Update a ConfigMap

  1. Create an environments.userWorkloadsConfigMaps.update API request.

  2. In this request:

    1. In the request body, in the name field, specify the URI of the ConfigMap.
    2. In the request body, in the data field, specify keys and values for the ConfigMap. The values will be replaced.

Example:

// PUT https://composer.googleapis.com/v1beta1/projects/example-project/
// locations/us-central1/environments/example-environment/userWorkloadsConfigMaps/example-configmap

{
  "name": "projects/example-project/locations/us-central1/environments/example-environment/userWorkloadsConfigMaps/example-configmap",
  "data": {
    "example_key": "example_value",
    "another_key": "another_value"
  }
}

List ConfigMaps

Create an environments.userWorkloadsConfigMaps.list API request. Key values in the output will be displayed as is. It's possible to use pagination with this request, see the request's reference for more details.

Example:

// GET https://composer.googleapis.com/v1beta1/projects/example-project/
// locations/us-central1/environments/example-environment/userWorkloadsConfigMaps

Get ConfigMap's details

Create an environments.userWorkloadsConfigMaps.get API request. Key values in the output will be displayed as is.

Example:

// GET https://composer.googleapis.com/v1beta1/projects/example-project/
// locations/us-central1/environments/example-environment/userWorkloadsConfigMaps/example-configmap

Delete a ConfigMap

Create an environments.userWorkloadsConfigMaps.delete API request.

Example:

// DELETE https://composer.googleapis.com/v1beta1/projects/example-project/
// locations/us-central1/environments/example-environment/userWorkloadsConfigMaps/example-configmap

Terraform

The google_composer_user_workloads_config_map resource defines a ConfigMap, with keys and values defined in the data block.

resource "google_composer_user_workloads_config_map" "example_config_map" {
  provider = google-beta
  environment = google_composer_environment.ENVIRONMENT_RESOURCE_NAME.name
  name = "CONFIG_MAP_NAME"
  region = "LOCATION"

  data = {
    KEY_NAME: "KEY_VALUE"
  }
}
  • ENVIRONMENT_RESOURCE_NAME: the name of the environment's resource, which contains the definition of the environment in Terraform. The actual environment's name is also specified in this resource.
  • LOCATION: the region where the environment is located.
  • CONFIG_MAP_NAME: the name of the ConfigMap.
  • KEY_NAME: one or more keys for this ConfigMap.
  • KEY_VALUE: Value for the key.

Example:

resource "google_composer_user_workloads_config_map" "example_config_map" {
  provider = google-beta

  name = "example-config-map"

  environment = google_composer_environment.example_environment.name
  region = "us-central1"

  data = {
    "example_key": "example_value"
  }
}

Use ConfigMaps in your DAGs

This example shows how to use ConfigMaps in your DAGs.

In the following example, a ConfigMap is passed in the configmaps parameter. All keys of this ConfigMap are available as environment variables:

import datetime

from airflow import models
from airflow.providers.cncf.kubernetes.operators.pod import KubernetesPodOperator

with models.DAG(
    dag_id="composer_kubernetes_pod_configmap",
    schedule_interval=None,
    start_date=datetime.datetime(2024, 1, 1),
) as dag:

  KubernetesPodOperator(
    task_id='kpo_configmap_env_vars',
    image='busybox:1.28',
    cmds=['sh'],
    arguments=[
        '-c',
        'echo "Value: $example_key"',
    ],
    configmaps=["example-configmap"],
    config_file="/home/airflow/composer_kube_config",
  )

The following example shows how to mount a ConfigMap as a volume:

import datetime

from airflow import models
from kubernetes.client import models as k8s
from airflow.providers.cncf.kubernetes.operators.pod import KubernetesPodOperator

volume_mount = k8s.V1VolumeMount(name='confmap-example',
  mount_path='/config',
  sub_path=None,
  read_only=False)

volume = k8s.V1Volume(name='confmap-example',
  config_map=k8s.V1ConfigMapVolumeSource(name='example-configmap'))

with models.DAG(
    dag_id="composer_kubernetes_pod_configmap",
    schedule_interval=None,
    start_date=datetime.datetime(2024, 1, 1),
) as dag:

  KubernetesPodOperator(
    task_id='kpo_configmap_volume_mount',
    image='busybox:1.28',
    cmds=['sh'],
    arguments=[
        '-c',
        'ls /config'
    ],
    volumes=[volume],
    volume_mounts=[volume_mount],
    configmaps=["example-configmap"],
    config_file="/home/airflow/composer_kube_config",
  )

Information about CNCF Kubernetes Provider

KubernetesPodOperator is implemented in apache-airflow-providers-cncf-kubernetes provider.

For detailed release notes for CNCF Kubernetes provider refer to CNCF Kubernetes Provider website.

Resource requirements

Cloud Composer 3 supports the following values for resource requirements. For an example of using resource requirements, see Additional configuration.

Resource Minimum Maximum Step
CPU 0.25 32 Step values: 0.25, 0.5, 1, 2, 4, 6, 8, 10, ..., 32. Requested values are rounded up to the closest supported step value (for example, 5 to 6).
Memory 2G (GB) 128G (GB) Step values: 2, 3, 4, 5, ..., 128. Requested values are rounded up to the closest supported step value (for example, 3.5G to 4G).
Storage - 100G (GB) Any value. If more than 100 GB are requested, only 100 GB are provided.

For more information about resource units in Kubernetes, see Resource units in Kubernetes.

Troubleshooting

This section provides advice for troubleshooting common KubernetesPodOperator issues:

View logs

When troubleshooting issues, you can check logs in the following order:

  1. Airflow Task logs:

    1. In the Google Cloud console, go to the Environments page.

      Go to Environments

    2. In the list of environments, click the name of your environment. The Environment details page opens.

    3. Go to the DAGs tab.

    4. Click the name of the DAG, then click the DAG run to view the details and logs.

  2. Airflow scheduler logs:

    1. Go to the Environment details page.

    2. Go to the Logs tab.

    3. Inspect Airflow scheduler logs.

  3. User Workloads logs:

    1. Go to the Environment details page.

    2. Go to the Monitoring tab.

    3. Select User Workloads.

    4. Inspect the list of executed workloads. You can view the logs and resource utilization information for each workload.

Non-zero return codes

When using KubernetesPodOperator (and GKEStartPodOperator), the return code of the container's entry point determines whether the task is considered successful or not. Non-zero return codes indicate failure.

A common pattern is to execute a shell script as the container entry point to group together multiple operations within the container.

If you are writing such a script, we recommended that you include the set -e command at the top of the script so that failed commands in the script terminate the script and propagate the failure to the Airflow task instance.

Pod timeouts

The default timeout for KubernetesPodOperator is 120 seconds, which can result in timeouts occurring before larger images download. You can increase the timeout by altering the startup_timeout_seconds parameter when you create the KubernetesPodOperator.

When a Pod times out, the task specific log is available in the Airflow UI. For example:

Executing <Task(KubernetesPodOperator): ex-all-configs> on 2018-07-23 19:06:58.133811
Running: ['bash', '-c', u'airflow run kubernetes-pod-example ex-all-configs 2018-07-23T19:06:58.133811 --job_id 726 --raw -sd DAGS_FOLDER/kubernetes_pod_operator_sample.py']
Event: pod-name-9a8e9d06 had an event of type Pending
...
...
Event: pod-name-9a8e9d06 had an event of type Pending
Traceback (most recent call last):
  File "/usr/local/bin/airflow", line 27, in <module>
    args.func(args)
  File "/usr/local/lib/python2.7/site-packages/airflow/bin/cli.py", line 392, in run
    pool=args.pool,
  File "/usr/local/lib/python2.7/site-packages/airflow/utils/db.py", line 50, in wrapper
    result = func(*args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/airflow/models.py", line 1492, in _run_raw_task
    result = task_copy.execute(context=context)
  File "/usr/local/lib/python2.7/site-packages/airflow/contrib/operators/kubernetes_pod_operator.py", line 123, in execute
    raise AirflowException('Pod Launching failed: {error}'.format(error=ex))
airflow.exceptions.AirflowException: Pod Launching failed: Pod took too long to start

Pod Timeouts can also occur when the Cloud Composer Service Account lacks the necessary IAM permissions to perform the task at hand. To verify this, look at Pod-level errors using the GKE Dashboards to look at the logs for your particular Workload, or use Cloud Logging.

KubernetesPodOperator tasks fail when a large number of tasks is executed

When your environment executes a large number of KubernetesPodOperator or KubernetesExecutor tasks at the same time, Cloud Composer 3 doesn't accept new tasks until some of the existing tasks are finished.

For more information about troubleshooting this issue, see Troubleshooting KubernetesExecutor tasks.

What's next