Consistently configure & start the ZooKeeper across all service systems

[jeffbyrnes]

Discovered a number of issues while debugging the Upstart script:

• Upstart & SysV services were not set to start immediately, unlike runit (the default)
• Env vars are not consistently applied
  • The runit style just uses the env var systems built-in to ZooKeeper (using zkServer.sh and zkEnv.sh)
  • SysV and Upstart have an /etc/default/zookeeper that sets up their own env vars
  • SysV still uses the zkServer.sh script, which does the same env var dance as runit, but with the overrides coming in from /etc/default/zookeeper
  • Upstart avoids zkServer.sh and handles ZooKeeper directly

Solutions:

• Avoid creating /etc/default/zookeeper, and just use the zookeeper-env.sh file that ZK sources in its own scripts (we already have a mechanism in place to populate this file)
• Avoid starting ZooKeeper directly from a service script, always use zkServer.sh

Fixes #179

[jeffbyrnes]

Don’t have any more cycles for this at the moment, I’ll try to circle back later this week or next week.

[jeffbyrnes]

Frustratingly, the SysV stuff works & tests well on a second convergence. Something about how it starts ZooKeeper means it can’t read/write fast enough to converge the zookeeper_node resources in the zookeeper_tester cookbook.

[jeffbyrnes]

Going to go ahead & merge this in; it’s at least as good as the current state of things for SysV, and a vast improvement for Upstart.