This is a re-architect of the vmpooler initialisation code to:
1. Allow an API service for both manager and the api
2. Add the Prometheus endpoints to the web service.
Needed to change the way the Rack Service is started as instantiating
using ".New" leads to a failure to initialise the http Stats
collection.
3. Selectively load the pooler api and/or Prometheus endpoints.
4. Rework API Spec tests for revised API loading. Needed to tidy up the
initialisation and perform a reset! after each test to avoid "leaks"
and dependencies between the tests.
This change adds a capability to vmpooler to provision instances on
demand. Without this change vmpooler only supports retrieving machines
from pre-provisioned pools.
Additionally, this change refactors redis interactions to reduce round
trips to redis. Specifically, multi and pipelined redis commands are
added where possible to reduce the number of times we are calling redis.
To support the redis refactor the redis interaction has changed to
leveraging a connection pool. In addition to offering multiple
connections for pool manager to use, the redis interactions in pool
manager are now thread safe.
Ready TTL is now a global parameter that can be set as a default for all
pools. A default of 0 has been removed, because this is an unreasonable
default behavior, which would leave a provisioned instance in the pool
indefinitely.
Pool empty messages have been removed when the pool size is set to 0.
Without this change, when a pool was set to a size of 0 the API and pool
manager would both show that a pool is empty.
This commit updates vmpooler gem dependencies in Gemfile and gemspec files. Without this change vmpooler is pinned to out of date version of multiple libraries.
This commit adds the spicy-proton gem to vmpooler.gemspec. Without this change the spicy-proton gem is in the Gemfile, but not the gemspec, causing issues when deploying from gem.
This commit updates get_vm in the vmpooler API to allow for setting weights for backends. Additionally, when an alias for a pool exists, and the backend configured is not weighted, then the selection of the pool based on alias will be randomly sampled. Without this change any pool with the title of the alias is exhausted before an alternate pool with the configured alias is used, which results in an uneven distribution of VMs. When all backends involved are configured with weighted values the VM selection will be based on probability using those weights.
A bug is fixed when setting the default ttl for check_ready_vm.
Pickup is added to handle weighted VM selection.
A dockerfile is added that allows for building and installing vmpooler
from the current HEAD in docker to make for easy testing.
This commit updates gemspec and Gemfile in preparation of a vmpooler release. To support this change the vmpooler executable is placed into a bin directory for inclusion in the gem. The license in gemspec is updated to Apache 2.0 to reflect the vmpooler project license.
