Plugin output chaining #23
Description
Proposal:
I introduced the hook system in #21, so that plugins can attach to them and run with their priority. However, at the moment, the results are not stored or passed through to the next one in the chain of the same hook. Going forward, plugin output chaining should be introduced between the hook and plugins. Also the results should be returned to the calling function. For example, plugin A wants to rewrite the query, so it hooks to the onIngressTraffic (formerly onIncomingTraffic). Then, plugin B wants to add a unique trace ID to the same query after plugin B, so it registers with the same hook, but lower priority (higher prio number). The result of plugin A should be returned to the Proxy.PassThrough function and then the function should pass the processed results to the next plugin in chain that was registered with the same hook, as depicted below:
I suspect it would be useful that the plugins receive both the raw query (from client) and the modified one by the plugins higher up in the chain.