support connection type as unique identifier along with id

[NNcrawler]

Problem
Raccoon supports unique websocket connections per user by specifying SERVER_WEBSOCKET_CONN_UNIQ_ID_HEADER configuration. There is a requirement to support connection types that is part of another header. Connection types combined with id will be used to maintain unique connections instead.

Which version was this found?
v0.1.0

Is there any workaround?
An alternative approach is to make user id globally unique.

What is the impact?
The current behavior is still supported. However, if SERVER_WEBSOCKET_CONN_TYPE_HEADER config is provided, Raccoon will use the header value together with id for uniqueness.

Solution

• Add another configuration to specify connection type header key and use that connection type header value as connection identifier.
• Add conn_type tags to each sensible metrics.

[ravisuhag]

@NNcrawler SERVER_WEBSOCKET_CONN_GROUP_HEADER Would this be better instead of TYPE. WDYT?

[NNcrawler]

Ya, that will avoid the confusion.