Master Trait

Deprecated since2.9.0 The Master trait allows to configure the integration to automatically leverage Kubernetes resources for doing leader election and starting master routes only on certain instances.

It’s activated automatically when using the master endpoint in a route, e.g. from("master:lockname:telegram:bots")…​.

this trait adds special permissions to the integration service account in order to read/write configmaps and read pods. It’s recommended to use a different service account than "default" when running the integration.
The Master trait is deprecated and will be removed in future release versions. This trait requires the operator to manage RBAC explicitly, which should be avoided for security and simplicity reasons. Users should manually create the required Role and RoleBinding, then configure Quarkus properties directly: 
-p quarkus.camel.cluster.kubernetes.resource-name=<integration>-lock
-p quarkus.camel.cluster.kubernetes.resource-type=Lease
-p quarkus.camel.cluster.kubernetes.labels."camel.apache.org/integration"=<integration-name>

This trait is available in the following profiles: Kubernetes, Knative, OpenShift.

Configuration

Trait properties can be specified when running any integration with the CLI:

$ kamel run --trait master.[key]=[value] --trait master.[key2]=[value2] integration.yaml

The following configuration options are available:

Property Type Description

master.enabled

bool

Can be used to enable or disable a trait. All traits share this common property.

master.auto

bool

Enables automatic configuration of the trait.

master.include-delegate-dependencies

bool

When this flag is active, the operator analyzes the source code to add dependencies required by delegate endpoints. E.g. when using master:lockname:timer, then camel:timer is automatically added to the set of dependencies. It’s enabled by default.

master.resource-name

string

Name of the configmap that will be used to store the lock. Defaults to "<integration-name>-lock". Name of the configmap/lease resource that will be used to store the lock. Defaults to "<integration-name>-lock".

master.resource-type

string

Type of Kubernetes resource to use for locking ("ConfigMap" or "Lease"). Defaults to "Lease".

master.label-key

string

Label that will be used to identify all pods contending the lock. Defaults to "camel.apache.org/integration".

master.label-value

string

Label value that will be used to identify all pods contending the lock. Defaults to the integration name.

Migration Guide

The Master trait is deprecated and will be removed in a future release. This trait requires the operator to manage RBAC explicitly, which should be avoided for security and simplicity reasons.

Why Migrate?

  • Reduced Operator Permissions: The operator no longer needs permissions to create Role and RoleBinding resources

  • Explicit RBAC Control: Users have full control over the RBAC configuration

  • Simplified Security Model: Better separation of concerns between integration and infrastructure

Migration Steps

Step 1: Create RBAC Resources Manually

Apply the following RBAC resources to your namespace:

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: <integration-name>-master
rules:
  - apiGroups:
      - coordination.k8s.io
    resources:
      - leases
    verbs:
      - create
      - delete
      - deletecollection
      - get
      - list
      - patch
      - update
      - watch
  - apiGroups:
      - ""
    resources:
      - pods
    verbs:
      - get
      - list
      - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: <integration-name>-master
subjects:
  - kind: ServiceAccount
    name: <service-account-name>
roleRef:
  kind: Role
  name: <integration-name>-master
  apiGroup: rbac.authorization.k8s.io

Step 2: Configure Quarkus Properties

Instead of using the trait properties, configure the equivalent Quarkus properties directly:

Master Trait Property Quarkus Property Description

master.resource-name

quarkus.camel.cluster.kubernetes.resource-name

Name of the lock resource

master.resource-type

quarkus.camel.cluster.kubernetes.resource-type

Type of Kubernetes resource (Lease or ConfigMap)

master.label-key / master.label-value

quarkus.camel.cluster.kubernetes.labels."<key>"

Labels for pod identification

Example Migration

Before (using deprecated trait):

$ kamel run MyRoute.java \
  -t master.resource-name=my-lock \
  -t master.resource-type=Lease \
  -t master.label-key=leader-group \
  -t master.label-value=my-group

After (using Quarkus properties):

# First apply the RBAC resources
$ kubectl apply -f master-rbac.yaml

# Then run with Quarkus properties
$ kamel run MyRoute.java \
  --service-account my-integration-sa \
  -p quarkus.camel.cluster.kubernetes.resource-name=my-lock \
  -p quarkus.camel.cluster.kubernetes.resource-type=Lease \
  -p quarkus.camel.cluster.kubernetes.labels."leader-group"=my-group

Notes

  • The master: component in Camel routes continues to work; only the automatic RBAC creation is removed

  • Ensure the service account used by the integration has the necessary permissions

  • For existing integrations, create the RBAC resources before removing the trait configuration

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