Bug: processor condition doesn't allow dict access to .Metadata

[rauanmayemir]

Bug description

Processor crashes with:

failed to build source processor tasks: invalid condition: template: :1: bad character U+005B '['" stack=[{"file":"github.com/conduitio/[email protected]/pkg/provisioning/service.go","func":"github.com/conduitio/conduit/pkg/provisioning.(*Service).Init","line":132},{"file":"github.com/conduitio/[email protected]/pkg/provisioning/service.go","func":"github.com/conduitio/conduit/pkg/provisioning.(*Service).provisionPipeline","line":260},{"file":"github.com/conduitio/[email protected]/pkg/lifecycle-poc/service.go","func":"github.com/conduitio/conduit/pkg/lifecycle-poc.(*Service).Start","line":159},{"file":"github.com/conduitio/[email protected]/pkg/lifecycle-poc/service.go","func":"github.com/conduitio/conduit/pkg/lifecycle-poc.(*Service).buildRunnablePipeline","line":301},{"file":"github.com/conduitio/[email protected]/pkg/lifecycle-poc/service.go","func":"github.com/conduitio/conduit/pkg/lifecycle-poc.(*Service).buildSourceTasks","line":411},{"file":"github.com/conduitio/[email protected]/pkg/processor/service.go","func":"github.com/conduitio/conduit/pkg/processor.(*Service).MakeRunnableProcessor","line":105}]

Steps to reproduce

Have a processor with a condition like this:

- id: route_default
  plugin: 'filter'
  condition: '{{ ne .Metadata["outbox.route"] "default" }}'

Version

v0.13.4

[lovromazgon]

That's because the condition is a pure Go template and doesn't accept the map syntax. You have to use the index function to access the field:

{{ ne (index .Metadata "outbox.route") "default" }}

Runnable example: https://go.dev/play/p/XXAeCG6wTET

The confusing part might be that Conduit accepts the syntax you wrote above when referencing record fields. That only applies to certain configuration options in processors, mostly ones called field that configure the processor to work on a specific field (for instance field in avro.decode). This syntax should not be confused with Go templates, even if they look similar.