fix(spring-config): init OkapiMicrometerAutoConfiguration considering multiple PTMs

[rawo]

Fixes #80: OkapiMicrometerAutoConfiguration.micrometerOutboxMetrics() crashed Spring context startup with NoUniqueBeanDefinitionException whenever 2+ PlatformTransactionManager beans were present — even when okapi.transaction-manager-qualifier was set to disambiguate, since it never looked at that property at all. It used a bare ObjectProvider.getIfAvailable(), which throws on ambiguity instead of returning null or honoring a qualifier.

OutboxAutoConfiguration already had correct qualifier-aware resolution logic (resolvePlatformTransactionManager()), just not shared.

What changed

• Extracted the qualifier-lookup half of OutboxAutoConfiguration.resolvePlatformTransactionManager() into a new internal resolvePlatformTransactionManagerByQualifier(beanFactory, qualifier), including its okapi-specific error rewrapping (actionable messages for "no bean with that name" and "bean exists but is the wrong type" — e.g. a DataSource name typoed into the qualifier property). resolvePlatformTransactionManager() now delegates to it instead of duplicating the logic.
• OkapiMicrometerAutoConfiguration.micrometerOutboxMetrics() now uses the same resolver: if okapi.transaction-manager-qualifier is set, resolve that specific bean (throwing the same actionable errors OutboxAutoConfiguration would); otherwise fall back to ObjectProvider.getIfUnique(), which returns null on ambiguity instead of throwing. The PTM stays optional here (unlike OutboxAutoConfiguration's required one) — metrics just run without a read-only snapshot transaction when none is available or the beans are ambiguous.
• @EnableConfigurationProperties on OkapiMicrometerAutoConfiguration now also registers OkapiProperties, needed to read the qualifier.

No behavior change for the existing single-PTM or zero-PTM cases; this only changes what happens when 2+ PlatformTransactionManager beans are present.

Test plan

• New OkapiMicrometerAutoConfigurationTest (7 cases): reproduces the OkapiMicrometerAutoConfiguration should reuse transaciton init function OutboxAutoConfiguration.resolvePlatformTransactionManager() #80 crash with 2 PTM beans and no qualifier, confirms the qualifier fixes it, confirms a bad qualifier value still fails fast with an actionable message (proving the resolver is actually shared, not reimplemented), confirms the zero-PTM case still starts, and confirms — via TransactionSynchronizationManager resource binding — that the correct DataSource backs the read-only snapshot transaction in each case (qualifier picks the right one; no qualifier + single PTM uses it; no qualifier + ambiguous PTMs runs without a transaction rather than picking arbitrarily)
• ./gradlew :okapi-spring-boot:ktlintCheck clean
• ./gradlew :okapi-spring-boot:test green, including existing OutboxAutoConfiguration transaction-manager-resolution tests (unaffected by the extraction)

[Copilot]

Pull request overview

Fixes Spring context startup failures in OkapiMicrometerAutoConfiguration.micrometerOutboxMetrics() when multiple PlatformTransactionManager beans are present by honoring okapi.transaction-manager-qualifier and avoiding ambiguous provider lookups.

Changes:

• Extracted qualifier-based PTM resolution into OutboxAutoConfiguration.resolvePlatformTransactionManagerByQualifier(...) and reused it from the required-PTM resolver.
• Updated OkapiMicrometerAutoConfiguration.micrometerOutboxMetrics() to (a) resolve the qualifier explicitly when configured, otherwise (b) use ObjectProvider.getIfUnique() so ambiguity results in “no PTM” rather than a startup crash.
• Added a dedicated regression test suite covering multiple-PTM, qualifier, bad qualifier, and no-PTM scenarios (including verification of which DataSource is bound during the snapshot transaction).

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
okapi-spring-boot/src/test/kotlin/com/softwaremill/okapi/springboot/OkapiMicrometerAutoConfigurationTest.kt	Adds regression and behavior tests for PTM selection logic and startup stability under multiple PTMs.
okapi-spring-boot/src/main/kotlin/com/softwaremill/okapi/springboot/OutboxAutoConfiguration.kt	Extracts and reuses qualifier-based PTM lookup with Okapi-specific error context.
okapi-spring-boot/src/main/kotlin/com/softwaremill/okapi/springboot/OkapiMicrometerAutoConfiguration.kt	Updates Micrometer metrics auto-config to honor qualifier and avoid ambiguous PTM resolution crashes.

Comments suppressed due to low confidence (1)

okapi-spring-boot/src/main/kotlin/com/softwaremill/okapi/springboot/OutboxAutoConfiguration.kt:313

• Similarly, this message suggests that removing okapi.transaction-manager-qualifier will reliably fall back to auto-resolution. For the outbox scheduler path, auto-resolution can still fail when multiple PTMs exist without a unique/@primary candidate. Consider clarifying that the fallback may still require disambiguation.

                    "okapi.transaction-manager-qualifier='$qualifier' — bean named '$qualifier' exists " +
                        "but is of type '${e.actualType.name}', not a PlatformTransactionManager. Check " +
                        "the property value (likely a typo into a DataSource or other bean name) or " +
                        "remove it to fall back to auto-resolution.",

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.