Apache Camel 4.x Upgrade Guide
This document is for helping you upgrade your Apache Camel application from Camel 4.x to 4.y. For example, if you are upgrading Camel 4.0 to 4.2, then you should follow the guides from both 4.0 to 4.1 and 4.1 to 4.2.
| The Camel Upgrade Recipes project provides automated assistance for some common migration tasks. Note that manual migration is still required. See the documentation page for details. |
Upgrading Camel 4.20 to 4.21
camel-yaml-dsl
A new canonical JSON Schema variant (camelYamlDsl-canonical.json) has been added alongside the existing classic schema (camelYamlDsl.json). The canonical schema removes all implicit patterns (string shorthands, inline expressions, oneOf/anyOf/not constructs) to provide a simpler, more predictable schema for tooling such as IDEs, code generators, and AI assistants. See the YAML DSL documentation for details.
The YamlValidator class now accepts a boolean canonical constructor parameter to validate against the canonical schema.
A new camel yaml normalize command has been added to Camel JBang. It rewrites YAML routes from the classic (shorthand) form to the canonical (explicit) form. The camel validate yaml command also supports a new --canonical flag to validate against the canonical schema.
camel-kafka / Spring Boot
When using camel-kafka-starter with Spring Boot, the standard spring.kafka. properties are now automatically bridged to the Camel Kafka component configuration (CAMEL-22760). This means you no longer need to duplicate Kafka settings under both spring.kafka. and camel.component.kafka.*.
The bridged properties include bootstrap-servers, security.protocol, SSL/TLS settings (keystore, truststore), consumer.group-id, client-id, and SASL properties (sasl.mechanism, sasl.jaas.config, sasl.kerberos.service.name).
Explicit camel.component.kafka.* settings always take precedence over the bridged Spring Boot values.
The bridge is enabled by default. To disable it, set:
camel.component.kafka.bridge-spring-kafka-properties=false