Function

WARNING: The current API version is serverless.kyma-project.io/v1alpha2. The serverless.kyma-project.io/v1alpha1 version is still supported but deprecated. For the v1alpha1 version, see the previous Function documentation.

The functions.serverless.kyma-project.io CustomResourceDefinition (CRD) is a detailed description of the kind of data and the format used to manage Functions within Kyma. To get the up-to-date CRD and show the output in the YAML format, run this command:

Click to copy

kubectl get crd functions.serverless.kyma-project.io -o yaml

Sample custom resource

The following Function object creates a Function which responds to HTTP requests with the "Hello John" message. The Function's code (source) and dependencies (dependencies) are specified in the Function CR.

Click to copy

apiVersion: serverless.kyma-project.io/v1alpha2
kind: Function
metadata:
  name: my-test-function
  namespace: default
  labels:
    app: my-test-function
spec:
  runtime: nodejs16
  source:
    inline:
      dependencies: |
        {
          "name": "hellowithdeps",
          "version": "0.0.1",
          "dependencies": {
            "end-of-stream": "^1.4.1",
            "from2": "^2.3.0",
            "lodash": "^4.17.5"
          }
        }
      source: |
        module.exports = {
          main: function(event, context) {
            const name = process.env.PERSON_NAME;
            return 'Hello ' + name;
          }
        }
  scaleConfig:
    minReplicas: 3
    maxReplicas: 3
  resourceConfiguration:
    function:
      resources:
        limits:
          cpu: 1
          memory: 1Gi
        requests:
          cpu: 500m
          memory: 500Mi
    build:
      resources:
        limits:
          cpu: 2
          memory: 2Gi
        requests:
          cpu: 1
          memory: 1Gi
  env:
    - name: PERSON_NAME
      value: "John"
  secretMounts:
    - secretName: SECRET_NAME
      mountPath: /secret/mount/path
  status:
    conditions:
      - lastTransitionTime: "2020-04-14T08:17:11Z"
        message: "Deployment my-test-function-nxjdp is ready"
        reason: DeploymentReady
        status: "True"
        type: Running
      - lastTransitionTime: "2020-04-14T08:16:55Z"
        message: "Job my-test-function-build-552ft finished"
        reason: JobFinished
        status: "True"
        type: BuildReady
      - lastTransitionTime: "2020-04-14T08:16:16Z"
        message: "ConfigMap my-test-function-xv6pc created"
        reason: ConfigMapCreated
        status: "True"
        type: ConfigurationReady

If you store the Function's source code and dependencies in a Git repository and want the Function Controller to fetch them from it, use these parameters in the Function CR:

Click to copy

apiVersion: serverless.kyma-project.io/v1alpha2
kind: Function
metadata:
  name: my-test-function
spec:
  source:
    gitRepository:
      url: github.com/username/repo
      baseDir: "/"
      reference: "branchA"
      auth:
        type: basic
        secretName: secret-name
  runtime: "nodejs16"

Custom resource parameters

This table lists all the possible parameters of a given resource together with their descriptions:

Parameter	Required	Description
metadata.name	Yes	Specifies the name of the CR.
metadata.namespace	No	Defines the Namespace in which the CR is available. It is set to `default` unless you specify otherwise.
metadata.labels	No	Specifies the Function's Pod labels.
spec.runtime	Yes	Specifies the runtime of the Function. The available values are `nodejs16`, `nodejs16`, and `python39`.
spec.runtimeImageOverride	No	Specifies the runtimes image which must be used instead of the default one.
spec.source	Yes	Contains the Function's specification. Only one specification is allowed.
spec.source.inline	No	Defines Function as the inline Function.
spec.source.inline.dependencies	No	Specifies the Function's dependencies.
spec.source.inline.source	Yes	Provides the Function's full source code.
spec.source.gitRepository	No	Defines Function as git-sourced.
spec.source.gitRepository.url	Yes	Provides the address to the Git repository with the Function's code and dependencies. Depending on whether the repository is public or private and what authentication method is used to access it, the URL must start with the `http(s)`, `git`, or `ssh` prefix.
spec.source.gitRepository.baseDir	No	Specifies the relative path to the Git directory that contains the source code from which the Function is built.
spec.source.gitRepository.reference	No	Specifies either the branch name, tag or the commit revision from which the Function Controller automatically fetches the changes in the Function's code and dependencies.
spec.source.gitRepository.auth	No	Specifies that you must authenticate to the Git repository. Required for SSH.
spec.source.gitRepository.auth.type	Yes	Defines if you must authenticate to the repository with a password or token (`basic`), or an SSH key (`key`). For SSH, this parameter must be set to `key`.
spec.source.gitRepository.auth.secretName	Yes	Specifies the name of the Secret with credentials used by the Function Controller to authenticate to the Git repository in order to fetch the Function's source code and dependencies. This Secret must be stored in the same Namespace as the Function CR.
spec.env	No	Specifies an array of key-value pairs to be used as environment variables for the Function. You can define values as static strings or reference values from ConfigMaps or Secrets.
spec.resourceConfiguration	No	Specifies resources requested by Function and build Job.
spec.resourceConfiguration.function	No	Specifies resources requested by the Function's Pod.
spec.resourceConfiguration.function.profile	No	Defines name of predefined set of values of resource. Can't be used at the same time with spec.resourceConfiguration.function.resources.
spec.resourceConfiguration.function.resources	No	Defines amount of resources available for the Function's Pod to use. Can't be used at the same time with spec.resourceConfiguration.function.profile.
spec.resourceConfiguration.function.resources.limits.cpu	No	Defines the maximum number of CPUs available for the Function's Pod to use.
spec.resourceConfiguration.function.resources.limits.memory	No	Defines the maximum amount of memory available for the Function's Pod to use.
spec.resourceConfiguration.function.resources.requests.cpu	No	Specifies the number of CPUs requested by the Function's Pod to operate.
spec.resourceConfiguration.function.resources.requests.memory	No	Specifies the amount of memory requested by the Function's Pod to operate.
spec.resourceConfiguration.build	No	Specifies resources requested by the build Job's Pod.
spec.resourceConfiguration.build.profile	No	Defines name of predefined set of values of resource. Can't be used at the same time with spec.resourceConfiguration.build.resources.
spec.resourceConfiguration.build.resources	No	Defines amount of resources available for the build Job's Pod to use. Can't be used at the same time with spec.resourceConfiguration.build.profile.
spec.resourceConfiguration.build.resources.limits.cpu	No	Defines the maximum number of CPUs available to use for the Kubernetes Job's Pod responsible for building the Function's image.
spec.resourceConfiguration.build.resources.limits.memory	No	Defines the maximum amount of memory available for the Job's Pod to use.
spec.resourceConfiguration.build.resources.requests.cpu	No	Specifies the number of CPUs requested by the build Job's Pod to operate.
spec.resourceConfiguration.build.resources.requests.memory	No	Specifies the amount of memory requested by the build Job's Pod to operate.
spec.replicas	No	Defines the exact number of Function's Pods to run at a time. If spec.scaleConfig is configured, or if Function is targeted by an external scaler, then the spec.replicas field is used by the relevant HorizontalPodAutoscaler to control the number of active replicas.
spec.scaleConfig	No	Defines minimum and maximum number of Function's Pods to run at a time. When it is configured, a HorizontalPodAutoscaler will be deployed and will control the spec.replicas field to scale Function based on the CPU utilisation.
spec.scaleConfig.minReplicas	Yes	Defines the minimum number of Function's Pods to run at a time.
spec.scaleConfig.maxReplicas	Yes	Defines the maximum number of Function's Pods to run at a time.
spec.secretMounts	No	Specifies Secrets to mount into the Function's container filesystem.
spec.secretMounts.secretName	Yes	Specifies name of the Secret in the Function's Namespace to use.
spec.secretMounts.mountPath	Yes	Specifies path within the container at which the Secret should be mounted.
status.conditions.lastTransitionTime	Not applicable	Provides a timestamp for the last time the Function's condition status changed from one to another.
status.conditions.message	Not applicable	Describes a human-readable message on the CR processing progress, success, or failure.
status.conditions.reason	Not applicable	Provides information on the Function CR processing success or failure. See the Reasons section for the full list of possible status reasons and their descriptions. All status reasons are in camelCase.
status.conditions.status	Not applicable	Describes the status of processing the Function CR by the Function Controller. It can be `True` for success, `False` for failure, or `Unknown` if the CR processing is still in progress. If the status of all conditions is `True`, the overall status of the Function CR is ready.
status.conditions.type	Not applicable	Describes a substage of the Function CR processing. There are three condition types that a Function has to meet to be ready: `ConfigurationReady`, `BuildReady`, and `Running`. When displaying the Function status in the terminal, these types are shown under `CONFIGURED`, `BUILT`, and `RUNNING` columns respectively. All condition types can change asynchronously depending on the type of Function modification, but all three need to be in the `True` status for the Function to be considered successfully processed.

Status reasons

Processing of a Function CR can succeed, continue, or fail for one of these reasons:

Reason	Type	Description
`ConfigMapCreated`	`ConfigurationReady`	A new ConfigMap was created based on the Function CR definition.
`ConfigMapUpdated`	`ConfigurationReady`	The existing ConfigMap was updated after changes in the Function CR name, its source code or dependencies.
`SourceUpdated`	`ConfigurationReady`	The Function Controller managed to fetch changes in the Functions's source code and configuration from the Git repository (`type: git`).
`SourceUpdateFailed`	`ConfigurationReady`	The Function Controller failed to fetch changes in the Functions's source code and configuration from the Git repository.
`JobFailed`	`BuildReady`	The image with the Function's configuration could not be created due to an error.
`JobCreated`	`BuildReady`	The Kubernetes Job resource that builds the Function image was created.
`JobUpdated`	`BuildReady`	The existing Job was updated after changing the Function's metadata or spec fields that do not affect the way of building the Function image, such as labels.
`JobRunning`	`BuildReady`	The Job is in progress.
`JobsDeleted`	`BuildReady`	Previous Jobs responsible for building Function images were deleted.
`JobFinished`	`BuildReady`	The Job was finished and the Function's image was uploaded to the Docker Registry.
`DeploymentCreated`	`Running`	A new Deployment referencing the Function's image was created.
`DeploymentUpdated`	`Running`	The existing Deployment was updated after changing the Function's image, scaling parameters, variables, or labels.
`DeploymentFailed`	`Running`	The Function's Pod crashed or could not start due to an error.
`DeploymentWaiting`	`Running`	The Function was deployed and is waiting for the Deployment to be ready.
`DeploymentReady`	`Running`	The Function was deployed and is ready.
`ServiceCreated`	`Running`	A new Service referencing the Function's Deployment was created.
`ServiceUpdated`	`Running`	The existing Service was updated after applying required changes.
`HorizontalPodAutoscalerCreated`	`Running`	A new Horizontal Pod Scaler referencing the Function's Deployment was created.
`HorizontalPodAutoscalerUpdated`	`Running`	The existing Horizontal Pod Scaler was updated after applying required changes.
`MinimumReplicasUnavailable`	`Running`	Insufficient number of available Replicas. The Function is unhealthy.

These are the resources related to this CR:

Custom resource	Description
ConfigMap	Stores the Function's source code and dependencies.
Job	Builds an image with the Function's code in a runtime.
Deployment	Serves the Function's image as a microservice.
Service	Exposes the Function's Deployment as a network service inside the Kubernetes cluster.
HorizontalPodAutoscaler	Automatically scales the number of Function's Pods.

These components use this CR:

Component	Description
Function Controller	Uses the Function CR for the detailed Function definition, including the environment on which it should run.

Function

Sample custom resource

Custom resource parameters

Status reasons

Related resources and components