Constraints enhance Mist's team policies with more nuanced control over machines.
In more details:
- With cost constraints you can configure cost quotas for your team and/or organization. Cost constraints help you stay within budget and avoid unpleasant surprises in your cloud bills.
- With expiration constraints you can enforce machine leases and take action automatically, shutting down and/or destroying machines, after the lease period has lapsed. Expiration constraints help you reduce machine sprawl and avoid long forgotten VMs running in vain for months.
- With size constraints you can control the amount of resources a new or resized machine can have. Size constraints help you avoid a fleet of unnecessary XL instances in AWS or a KVM host with all its resources dedicated to a single VM.
- With field constraints you can hide and/or suggest reasonable defaults for all provisioning options. Field constraints help you simplify the machine provisioning process for your end users.
All of the above can be combined to create the ideal policy for your organization.
Follow the links above for additional details and examples on how to configure the relevant constraints.
Notes and requirements
Constraints are available only in Mist Hosted Service (HS) and Mist Enterprise Edition (EE), versions v4.2 and later.
Constraints can be configured only by members of the Owners team. For more information on teams and role-based access controls check out this page.
To configure constraints click the gear icon next to rule that applies to machines and a web form will pop up.
The team policy rules that support constraints are:
- MACHINE: CREATE
- MACHINE: EDIT
- MACHINE: RESIZE
- MACHINE: ALL
If you add a constraint to a rule with the ALL action, the constraints will automatically be added to all types of actions, i.e. CREATE, EDIT and RESIZE.
The easiest way to configure constraints is through the web form. The form was introduced in Mist v4.5 and we didn't deprecate the old JSON-based interface. In fact, the JSON interface is very helpful when looking to quickly copy and paste the same policies to multiple teams. To edit constraints in JSON, toggle the JSON switch at the top right of the web form.