Support for multiple handlers with different routing keys

[csmcdermott]

This change allows you to create multiple handlers with different routing keys, ie:

{
"handlers": {
"victorops": {
"type": "pipe",
"command": "/etc/sensu/handlers/victorops.rb --routingkey everyone",
"severities": [
"ok",
"critical"
]
},
"victorops_database": {
"type": "pipe",
"command": "/etc/sensu/handlers/victorops.rb --routingkey victorops_database",
"severities": [
"ok",
"critical"
]
}
}
}

Alternatively you can leave the --routingkey option off and use this handler exactly like before - this change is backwards compatible.

[kalabiyau]

I think global variable here is too much for the purpose, instance variable would be enough.

[piavlo]

I was also thinking about implementing better key routing mechanism for vitctorops.
I have two ideas

1. just use the check name as routing key, and then map all the checks to different teams in victorops
   the not mapped checks will just go to default team.

2. similar to above but instead check name will be mapped to routing keys in sensu config, something like this

{
  "handlers": {
    "victorops": {
      "type": "pipe",
      "command": "/etc/sensu/handlers/victorops.rb"
    }
  },
  "victorops": {
    "api_url": "https://alert.victorops.com/integrations/generic/20131114/xxxxxxxxxxxxxxxxxxx",
    "routing_key": "the-default-fallback-routing-key"
    "routing":  {
      "check_mysql_replication": "database",
      "check_rabbitmq": "messaging",
      "check_disk": "system",
      ...
    }
  }
}

wdyt?

[kalabiyau]

@csmcdermott i think idea is worthy, please look at sensu-plugins/sensu-plugin#66 maybe you can later base your work on that

[kalabiyau]

Still blocked in sensu itself. Closing until that blocker is fixed.