Split federation plugin into two: one for queue and another for exchange federation

[dcorbacho]

Splitsrabbitmq_federation plugin into rabbitmq_queue_federation, rabbitmq_exchange_federation and rabbitmq_federation_common

[michaelklishin]

rabbitmq_federation Role

For those upgrading, we should make rabbitmq_federation depend on both of the new plugins, and otherwise be a no-op just like it is right now.

Testing Results

When I start a node with

gmake run-broker PLUGINS="rabbitmq_management rabbitmq_federation rabbitmq_queue_federation rabbitmq_exchange_federation rabbitmq_federation_management"

then the node fails to boot during the plugin startup phase with

  Starting broker...
1>
BOOT FAILED
===========
Exception during startup:

exit:{error,{{shutdown,{failed_to_start_child,q_links,{'EXIT',{undef,[{rabbit_federation_pg,start_scope,[rabbitmq_queue_federation_pg_scope],[]},{rabbit_federation_queue_link_sup_sup,start_link,0,[{file,"rabbit_federation_queue_link_sup_sup.erl"},{line,31}]},{supervisor,do_start_child_i,3,[{file,"supervisor.erl"},{line,996}]},{supervisor,do_start_child,3,[{file,"supervisor.erl"},{line,982}]},{supervisor,'-start_children/2-fun-0-',3,[{file,"supervisor.erl"},{line,966}]},{supervisor,children_map,4,[{file,"supervisor.erl"},{line,1891}]},{supervisor,init_children,2,[{file,"supervisor.erl"},{line,932}]},{gen_server,init_it,2,[{file,"gen_server.erl"},{line,2276}]}]}}}},{child,undefined,rabbit_federation_sup,{rabbit_federation_sup,start_link,[]},transient,false,300000,worker,[rabbit_federation_sup]}}}

    rabbit_boot_steps:-run_step/2-lc$^0/1-0-/2, line 57
    rabbit_boot_steps:run_step/2, line 60
    rabbit_boot_steps:-run_boot_steps/1-lc$^0/1-0-/1, line 24
    rabbit_boot_steps:run_boot_steps/1, line 25
    rabbit:start/2, line 994
    application_master:start_it_old/4, line 299

{exit,terminating,[{application_controller,call,2,[{file,"application_controller.erl"},{line,515}]},{application,'-ensure_all_started/3-lc$^0/1-0-',1,[{file,"application.erl"},{line,368}]},{application,ensure_all_started,3,[{file,"application.erl"},{line,368}]},{rabbit,'-start_it/1-fun-0-',1,[{file,"src/rabbit.erl"},{line,425}]},{timer,tc,2,[{file,"timer.erl"},{line,599}]},{rabbit,start_it,1,[{file,"src/rabbit.erl"},{line,421}]},{init,start_it,1,[]},{init,start_em,1,[]}]}
Kernel pid terminated (application_controller) ("{application_start_failure,rabbit,{{error,{{shutdown,{failed_to_start_child,q_links,{'EXIT',{undef,[{rabbit_federation_pg,start_scope,[rabbitmq_queue_federation_pg_scope],[]},{rabbit_federation_queue_link_sup_sup,start_link,0,[{file,\"rabbit_federation_queue_link_sup_sup.erl\"},{line,31}]},{supervisor,do_start_child_i,3,[{file,\"supervisor.erl\"},{line,996}]},{supervisor,do_start_child,3,[{file,\"supervisor.erl\"},{line,982}]},{supervisor,'-start_children/2-fun-0-',3,[{file,\"supervisor.erl\"},{line,966}]},{supervisor,children_map,4,[{file,\"supervisor.erl\"},{line,1891}]},{supervisor,init_children,2,[{file,\"supervisor.erl\"},{line,932}]},{gen_server,init_it,2,[{file,\"gen_server.erl\"},{line,2276}]}]}}}},{child,undefined,rabbit_federation_sup,{rabbit_federation_sup,start_link,[]},transient,false,300000,worker,[rabbit_federation_sup]}}},{rabbit,start,[normal,[]]}}}")