A GCE backend for Machine Provider.
GCE Backend is composed of a series of cron jobs. Each cron runs independently of the others and performs idempotent operations. Many of the jobs are only eventually consistent, converging on the desired state over multiple calls.
<appid> below with your project id.Add Member and add someone else so you can safely be hit by a bus../tools/gae upl -x -A <appid>Proceed.instance\_url property of the components.machine_provider.utils.MachineProviderConfiguration entity in the datastore.TODO(smut): Move the following into doc/ as applicable.
The configuration defines the desired instance templates, and the desired instance group managers created from those templates. Configured in the config service as templates.cfg and managers.cfg respectively.
Responsible for importing the current GCE configuration from the config service. When a new config is detected, the local copy of the config in the datastore is updated. This task ensures that the valid manager and template configurations are updated synchronously.
Responsible for creating an entity structure corresponding to the config.
A models.InstanceTemplate is created for each template defined in templates.cfg which has a globally unique base_name. Any reuse of base_name, even when the configured project is different, is considered to be another revision of the same instance template. A revision of an instance template is one set of fields for it, and a corresponding models.InstanceTemplateRevision is created. Each time a template in templates.cfg with the same name has its other fields changed a new models.InstanceTemplateRevision is created for it.
A models.InstanceGroupManager is created for each manager defined in managers.cfg which refers to an existing template by template_base_name. At most one instance group manager in each zone may exist for each template.
Ensures a GCE instance template exists for each template in the config. Updates models.InstanceTemplateRevisions with the URL of the created instance template.
Ensures a GCE instance group manager exists for each manager in the config. Updates models.InstanceGroupManagers with the URL of the created instance group manager. Waits for an instance template to exist for the template the manager is configured to use before attempting to create the instance group manager.
Fetches the list of instances created by each instance group manager, creating a models.Instance for each one. Waits for the instance group manager to exist before attempting to fetch the list of instances.
Adds instances to the Machine Provider catalog. Any instance not cataloged and not pending deletion is added to the catalog.
Checks the state of the instance in the Machine Provider catalog. If the Machine Provider has leased the instance, that instance is marked as leased. If the Machine Provider has reclaimed the instance after lease expiration, schedules an operation to delete the GCE instance.
Deletes GCE instances for each models.Instance with pending_deletion set.
Embiggens a GCE managed instance group whose size has fallen below the minimum configured size.
Removes each models.Instance from the Machine Provider catalog that wasn't created from an instance template currently referenced in the config and sets pending_deletion.
Deletes GCE instance group managers that aren't found in the config and have no instances created from them.
Deletes GCE instance templates that aren't found in the config and have no instance group managers configured to use them.
Deletes entities that are no longer needed.