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 adds a capability to vmpooler to reset a pool, deleting its ready and pending instances and replacing them with fresh ones. Without this change vmpooler does not offer a mechanism to reset a pool without also changing its template.
This change adds the running host for a VM to the API data available via /vm/hostname. Without this change the running host would be logged to vmpooler log, but not available any other way. Additionally, the data will specify if a machine has been migrated. Without this change parent host data for a vmpooler machine is not available via the vmpooler API.
Prior to this commit the docs and examples used 'company.com'
(a real domain). This commit changes those occurrences to
'example.com', which is a IANA-managed reserved domain.
This commit adds a configuration endpoint to the vmpooler API. Pool
size, and pool template, can be adjusted for pools that are configured
at vmpooler application start time. Pool template changes trigger a pool
refresh, and the new template has delta disks created automatically by
vmpooler.
Additionally, the capability to create template delta disks is added to
the vsphere provider, and this is implemented to ensure that templates
have delta disks created at application start time.
The mechanism used to find template VM objects is simplified to make the flow of logic easier to understand. As an additional benefit, performance of this lookup is improved by using FindByInventoryPath.
A table of contents is added to API.md to ease navigation. Without this change API.md has no table of contents and is difficult to navigate.
Add mutex object for managing pool configuration updates
This commit adds a mutex object for ensuring that pool configuration changes are synchronized across multiple running threads, removing the possibility of two threads attempting to update something at once, without relying on redis data. Without this change this is managed crudely by specifying in redis that a configuration update is taking place. This redis data is left so the REPOPULATE section of _check_pool can still identify when a configuration change is in progress, and prevent a pool from repopulating at that time.
Add wake up event for pool template changes
This commit adds a wake up event to detect pool template changes.
Additionally, GET /config has a template_ready section added to the
output for each pool, which makes clear when a pool is ready to populate
itself.
This commit adds documentation for how to setup a development environment for
VM Pooler. This commit also moves the API under the new docs directory and
modifies the README appropriately.
