Fix #2263: add a Salesforce Pub/Sub source Kamelet

[oscerd]

Fixes #2263. Also covers the first half of #1546, which asks for the same thing — I have left that one open and commented there rather than closing it, because its second question about keystore authentication is separate and still unanswered.

The API has been there; the catalog had not caught up

camel-salesforce in 4.22 carries both Pub/Sub operations:

operationName enum -> [..., 'subscribe', 'pubSubSubscribe', 'pubSubPublish']

along with pubSubBatchSize, pubSubDeserializeType, pubSubPojoClass, pubSubReplayId, replayPreset, and host/port options. The catalog only had salesforce-source, which uses the older streaming API (subscribe, topics, notifyForOperation*). This adds a source for the gRPC one.

I did the source rather than both halves: #2263 asks about consuming, and a pubSubPublish sink is a clean follow-up rather than something to bundle here.

One default deliberately differs from the component

deserializeType defaults to JSON, where the component defaults to AVRO.

A Kamelet emits to kamelet:sink, and AVRO puts binary on the body that the next step has to decode before it is useful. JSON is usable as-is, which is the point of a Kamelet. All five values remain available, and the property description states plainly that AVRO is the component's own default so nobody is surprised.

A runtime caveat worth knowing about

Verifying this turned up something users will hit. Under Camel JBang the resolved protobuf-java is older than the generated gRPC stubs in camel-salesforce expect, and the route dies during class loading:

java.lang.NoClassDefFoundError: com/google/protobuf/RuntimeVersion$RuntimeDomain

That is before any endpoint is built, so it looks nothing like a configuration problem. Adding protobuf explicitly fixes it:

camel run route.yaml --dep=com.google.protobuf:protobuf-java:4.35.1

I put this in the Kamelet description rather than leaving it to be rediscovered.

I did not add it to spec.dependencies. It would work, and protobuf is BSD-3 so the licence is fine, but every pinned mvn: version in this catalog is managed from the root pom by the UpdateKamelets step — artemis-jakarta-client-all is the model. Hardcoding 4.35.1 here would drift from Camel the first time it moves. Wiring a managed protobuf-version property is the correct fix and is a maintainer decision about version coupling, so I have flagged it rather than made it. Say the word and I will do it properly.

Verification

script/validator reports no errors, script/generator adds the nav.adoc entry, mvn clean install passes with tests from the repository root.

With protobuf pinned, the Kamelet reaches a real login attempt and fails only on the deliberately invalid host:

Failed to start component local-salesforce-pubsub-1 because of
  SalesforceException: Unexpected login error: login.salesforce.invalid
Caused by: java.net.UnknownHostException

Every parameter binds and the gRPC path is exercised — the failure is the network, not the configuration.

No Citrus test: this needs a real Salesforce org, which no emulator provides. Ships Preview without kamelet.verified=true.

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Claude Code on behalf of Andrea Cosentino