event-plugin: beginning integration / metrics

[jonmorehouse]

This is pretty awesome!

2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 modify_request_plugin_latency 265.409µs
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 request-metric received ...
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 modify_request_plugin_latency 285.932µs
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 request-metric received ...
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 modify_request_plugin_latency 374.773µs
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 request-metric received ...
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 modify_request_plugin_latency 261.346µs
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 request-metric received ...
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 modify_request_plugin_latency 235.185µs
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 request-metric received ...
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 modify_request_plugin_latency 298.627µs
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 request-metric received ...
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 modify_request_plugin_latency 360.431µs
2016/06/13 03:28:07 [DEBUG] plugin: modifier: 2016/06/13 03:28:07 adding X-Request-ID header to the request
2016/06/13 03:28:07 [DEBUG] plugin: modifier: 2016/06/13 03:28:07 adding X-Request-ID header to the request
2016/06/13 03:28:07 [DEBUG] plugin: modifier: 2016/06/13 03:28:07 adding X-Request-ID header to the request
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 general-metric received ...
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 modify_response_plugin_latency 385.439µs
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 general-metric received ...
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 modify_response_plugin_latency 400.305µs
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 general-metric received ...
2016/06/13 03:28:07 [DEBUG] plugin: event-logger: 2016/06/13 03:28:07 modify_response_plugin_latency 410.596µs
2016/06/13 03:28:07 [DEBUG] plugin: modifier: 2016/06/13 03:28:07 adding X-Request-ID header to the request
2016/06/13 03:28:07 [DEBUG] plugin: modifier: 2016/06/13 03:28:07 adding X-Request-ID header to the request
2016/06/13 03:28:07 [DEBUG] plugin: modifier: 2016/06/13 03:28:07 adding X-Request-ID header to the request
2016/06/13 03:28:07 [DEBUG] plugin: modifier: 2016/06/13 03:28:07 adding X-Request-ID header to the request
2016/06/13 03:28:08 [DEBUG] plugin: modifier: 2016/06/13 03:28:08 adding X-Request-ID header to the request
2016/06/13 03:28:08 [DEBUG] plugin: modifier: 2016/06/13 03:28:08 adding X-Request-ID header to the request
2016/06/13 03:28:08 [DEBUG] plugin: modifier: 2016/06/13 03:28:08 adding X-Request-ID header to the request
2016/06/13 03:28:08 [DEBUG] plugin: modifier: 2016/06/13 03:28:08 adding X-Request-ID header to the request
2016/06/13 03:28:08 [DEBUG] plugin: modifier: 2016/06/13 03:28:08 adding X-Request-ID header to the request
2016/06/13 03:28:08 [DEBUG] plugin: modifier: 2016/06/13 03:28:08 adding X-Request-ID header to the request
2016/06/13 03:28:08 [DEBUG] plugin: modifier: 2016/06/13 03:28:08 adding X-Request-ID header to the request
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 468.672µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 382.546µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 389.923µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 417.203µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 410.947µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 377.167µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 401.077µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 390.125µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 398.01µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 398.883µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 general-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_response_plugin_latency 398.204µs
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 request-metric received ...
2016/06/13 03:28:08 [DEBUG] plugin: event-logger: 2016/06/13 03:28:08 modify_request_plugin_latency 265.807µs

Still needs a ton of work, but the event plugins are working end to end now.

[jonmorehouse]

The scope of this PR will include:

• [x] write metrics for plugin latencies
• [x] metricWrapper / figure out a way to clean things up
• [x] pass Metrics by value into metrics writer?
• [x] abstraction around metric logging?

[jonmorehouse]

A few other things happening here...

• InternalError type and adding general robustness around crazy edge cases
• shared.ProgrammingError
• Consolidate MultiError

[jonmorehouse]

Todo:

• [x] rename ErrorResponse to ModifyErrorResponse
• [x] rename upstream_requester to UpstreamRequester
• [x] modify main.go flags

[jonmorehouse]

Working end to end!