traits.adoc

Traits

Traits are high level named features of Camel K that can be enabled/disabled or configured to customize the behavior of the final integration.

Camel K provide sensible defaults for all such traits, taking into account the details of the target platform where the integration is going to run into. However, it’s possible for a expert user to configure them in order to obtain a different behavior.

Configuration

Each trait has a unique ID that can be used to configure it using the command line tool.

E.g. in order to disable the creation of a Service for a integration, a user can execute:

kamel run --trait service.enabled=false file.groovy

The flag --trait can be also abbreviated with -t.

The enabled property is available on all traits and can be used to enable/disable them. All traits have their own internal logic to determine if they need to be enabled when the user does not activate them explicitly.

All traits share also a auto property that can be used to enable/disable auto-configuration of the trait based on the environment. The auto-configuration mechanism is able to enable/disable the trait when the enabled property is not explicitly set by the user and also change the trait configuration. The auto property is enabled by default.

Note	Some traits are applicable only to specific platforms (see "profiles" in the table).

A trait may have additional properties that can be configured by the end user.

E.g. the following command configures the container port that should be exposed by the service:

kamel run --trait service.enabled=true --trait service.port=8081 file.groovy

Or the equivalent command (assuming that the service trait is enabled by auto-detection):

kamel run -t service.port=8081 file.groovy

Note	Enabling a trait does not force the trait to be activated, especially if the trait specific preconditions do not hold. E.g. enabling the route trait while the service trait is disabled does not produce automatically a route, since a service is needed for the route trait to work.

Common Traits

The following is a list of common traits that can be configured by the end users:

Trait	Profiles	Description
dependencies	Kubernetes, OpenShift	Automatically adds dependencies required by the Camel routes by inspecting the user code. It’s enabled by default.
deployer	Kubernetes, OpenShift	Configure deployer behavior. It’s enabled by default. deployer.container-image Generates a container image for the Integration that includes the sources and resources in the generated images instead of mounting them to the pod. deployer.kind Allows to explicitly select the desired deployment kind between deployment or knative-service when creating the resources for running the integration.
deployment	Kubernetes, OpenShift	Creates a standard Kubernetes deployment for running the integration. It’s enabled by default on vanilla Kubernetes/Openshift profiles.
affinity	All	Allows to constrain which nodes the integration pod(s) are eligible to be scheduled on, based on labels on the node, or with inter-pod affinity and anti-affinity, based on labels on pods that are already running on the nodes. It’s disabled by default. affinity.pod-affinity Always co-locates multiple replicas of the integration in the same node (default false). affinity.pod-affinity-labels Defines a set of pods (namely those matching the label selector, relative to the given namespace) that the integration pod(s) should be co-located with. affinity.pod-anti-affinity Never co-locates multiple replicas of the integration in the same node (default false). affinity.pod-anti-affinity-labels Defines a set of pods (namely those matching the label selector, relative to the given namespace) that the integration pod(s) should not be co-located with. affinity.node-affinity-labels Defines a set of nodes the integration pod(s) are eligible to be scheduled on, based on labels on the node. Examples: To schedule the integration pod(s) on a specific node using the built-in node label kubernetes.io/hostname: $ kamel run -t affinity.node-affinity-labels="kubernetes.io/hostname in(node-66-50.hosted.k8s.tld)" ... To schedule a single integration pod per node (using the Exists operator): $ kamel run -t affinity.node-anti-affinity-labels="camel.apache.org/integration" ... To co-locate the integration pod(s) with other integration pod(s): $ kamel run -t affinity.node-affinity-labels="camel.apache.org/integration in(it1, it2)" ... The labels options follow the requirements from Label selectors. They can be multi-valuated, then the requirements list is ANDed, e.g., to schedule a single integration pod per node AND not co-located with the Camel K operator pod(s): $ kamel run -t affinity.node-anti-affinity-labels="camel.apache.org/integration" -t affinity.node-anti-affinity-labels="camel.apache.org/component=operator" ... More information can be found in the official Kubernetes documentation about Assigning Pods to Nodes.
knative	Knative (Kubernetes, OpenShift)	Creates Knative resources to run the integration instead of the standard Kubernetes resources. It’s enabled by default when the Knative profile is active. knative.channel-sources Configures a (comma-separated) list of channels to which the Knative service must be subscribed (to receive cloudevents from a channel). knative.channel-sinks Configures a (comma-separated) list of channels to which the Knative service publishes. knative.endpoint-sources Configures a (comma-separated) list of endpoints the Knative service exposes (the name is). knative.endpoint-sinks Configures a (comma-separated) list of endpoints the Knative consumes. knative.filter-source-channels Force the knative endpoint to filter messages based on the ce-knativehistory header (Knative experimental feature). It’s enabled automatically when there are more than 2 source channels. It’s optional (default to false) when there’s a single source channel.
istio	Knative (Kubernetes, OpenShift)	Allows to configure outbound traffic for Istio. It’s enabled by default when the Knative profile is active. istio.allow Configures a (comma-separated) list of CIDR subnets that should not be intercepted by the Istio proxy (10.0.0.0/8,172.16.0.0/12,192.168.0.0/16 by default). istio.inject Forces the value for labels sidecar.istio.io/inject. By default the label is set to true on deployment and not set on Knative Service.
service	All (Knative in deployment mode)	Exposes the integration with a Service resource so that it can be accessed by other applications (or integrations) in the same namespace. It’s enabled by default if the integration depends on a Camel component that can expose a HTTP endpoint. service.port To configure a different port exposed by the container (default 8080).
route	OpenShift	Exposes the service associated with the integration to the outside world with a OpenShift Route. It’s enabled by default whenever a Service is added to the integration (through the service trait). route.host To configure the host exposed by the route.
ingress	Kubernetes	Exposes the service associated with the integration to the outside world with a Kubernetes Ingress. It’s enabled by default whenever a Service is added to the integration (through the service trait). ingress.host Required. To configure the host exposed by the ingress.
debug	All	Run the integration in debug mode (you can port-forward to port 5005 to connect) It’s disabled by default.
jolokia	Kubernetes, OpenShift	Activate and configures the Jolokia Java agent. It’s disabled by default. jolokia.protocol The protocol to use, either http or https (default https for OpenShift) jolokia.host The Host address to which the Jolokia agent should bind to. If "*" or "0.0.0.0" is given, the servers binds to every network interface (default "*"). jolokia.port The Jolokia endpoint port (default 8778). jolokia.user The user to be used for authentication jolokia.password The password used for authentication, applicable when the user option is set jolokia.discovery-enabled Listen for multicast requests (default false) jolokia.use-ssl-client-authentication Whether client certificates should be used for authentication (default true for OpenShift) jolokia.ca-cert The PEM encoded CA certification file path, used to verify client certificates, applicable when protocol is https and use-ssl-client-authentication is true (default /var/run/secrets/kubernetes.io/serviceaccount/ca.crt for OpenShift). jolokia.client-principal The principal which must be given in a client certificate to allow access to the Jolokia endpoint, applicable when protocol is https and use-ssl-client-authentication is true (default clientPrincipal=cn=system:master-proxy for OpenShift). jolokia.extended-client-check Mandate the client certificate contains a client flag in the extended key usage section, applicable when protocol is https and use-ssl-client-authentication is true (default true for OpenShift). jolokia.options A comma-separated list of additional Jolokia options as defined in JVM agent configuration options, e.g.: keystore=…​,executor=…​
prometheus	Kubernetes, OpenShift	Exposes the integration with a Service and a ServiceMonitor resources so that the Prometheus endpoint can be scraped. Warning Creating the ServiceMonitor resource requires the Prometheus Operator custom resource definition to be installed. You can set service-monitor to false for the Prometheus trait to work without the Prometheus operator. It’s disabled by default. prometheus.port The Prometheus endpoint port (default 9778). prometheus.service-monitor Whether a ServiceMonitor resource is created (default true). prometheus.service-monitor-labels The ServiceMonitor resource labels, applicable when service-monitor is true.
camel	All	Resolve Camel version It’s enabled by default. camel.version The camel version to use for the integration, it overrides the default version set in the Integration Platform

Platform Traits (Advanced)

There are also platform traits that normally should not be configured by the end user. So change them only if you know what you’re doing.

Trait	Profiles	Description
owner	All	Ensures that all created resources belong to the integration being created (so they are deleted when the integration is deleted) and transfers annotations and labels on the integration onto these owned resources. It’s enabled by default. owner.target-annotations The annotations to be transferred (A comma-separated list of label keys) owner.target-labels The labels to be transferred (A comma-separated list of label keys)
gc	All	Garbage collect resources that are no longer necessary upon integration updates. It’s enabled by default.