shepherd

Documentation

Index

• Variables
• type Availability
  • func (a Availability) String() string
• type CreateMachineRequest
• type Machine
• type Provider
• type ProviderID
  • func (p ProviderID) IsValid() bool
• type Recoverer

Variables

var ErrMachineNotFound = fmt.Errorf("machine not found")

var ErrNotImplemented = fmt.Errorf("not implemented")

Types

type Availability

type Availability int

Availability defines the availability state according to the provider. See the different states for more information.

const (
	// AvailabilityUndefined is used as a placeholder to prevent that the default
	// value can create any type of bad behaviour.
	AvailabilityUndefined Availability = iota
	// AvailabilityPossiblyUsed defines the state where a machine is possibly used,
	// this is a state for use in stateless providers where the shepherd has
	// to check against the bmdb if Machine.ID is already provisioned or not.
	// These machines must have a valid ID and Addr.
	AvailabilityPossiblyUsed
	// AvailabilityKnownUnused defines the state where a machine is know to be free,
	// e.g. a hardware reservation at equinix. These machines may not have an
	// ID or Addr.
	AvailabilityKnownUnused
	// AvailabilityKnownUsed defines the state where a machine is known to be used,
	// e.g. a deployed machine that is in use. These machines must have a
	// valid ID and Addr.
	AvailabilityKnownUsed
)

func (Availability) String

func (a Availability) String() string

type CreateMachineRequest

type CreateMachineRequest struct {
	// UnusedMachine resembles a machine to use as deployment target.
	UnusedMachine Machine
}

type Machine

type Machine interface {
	// ID returns the provider id, see ProviderID for more information.
	ID() ProviderID
	// Addr returns the machines ip address that is reachable from the
	// shepherd. It is used to connect to the machine via SSH to execute
	// all takeover tasks, etc.
	Addr() netip.Addr
	// Availability returns the availability of the machine.
	Availability() Availability
	// Failed should return true if the machine is in a failed state and
	// should be ignored if there are inconsistencies between the provider
	// and BMDB.
	Failed() bool
}

type Provider

type Provider interface {
	// ListMachines returns all existing machines for a provider. Machines
	// that are still in the state of being created by CreateMachine should
	// not be returned.
	ListMachines(context.Context) ([]Machine, error)

	// GetMachine returns an existing machine for a provider. Machines
	// that are still in the state of being created by CreateMachine should
	// not be returned. If a there are no machines found after these filters
	// an error should be returned.
	GetMachine(context.Context, ProviderID) (Machine, error)

	// CreateMachine creates a new machine with the given parameters and
	// returns the created instance. The provider is required to create the
	// entry into the machine table and MachineProvided tag. If there are no
	// more machines avaiable, an error should be returned.
	CreateMachine(context.Context, *bmdb.Session, CreateMachineRequest) (Machine, error)

	// Type returns the value that represents this provider inside the database.
	Type() model.Provider
}

Provider is the interface that is used to abstract the interaction between the shepherd and machine providers like Equinix. All methods inside this interface must not be called concurrently.

type ProviderID

type ProviderID string

ProviderID is an opaque unique identifier for a machine within a single provider instance. It is generated by the Provider and usually the same as the ID of the machine within the system that the Provider managed. The Shepherd (and BMaaS in general) requires these IDs to be unique within a provider and stable.

const InvalidProviderID ProviderID = "invalid"

func (ProviderID) IsValid

func (p ProviderID) IsValid() bool

IsValid reports whether the ProviderID is valid.

type Recoverer

type Recoverer interface {
	Provider

	// RebootMachine tries to bring a machine back from the dead by e.g. rebooting
	RebootMachine(context.Context, ProviderID) error

	// ReinstallMachine should reinstall the given machine and if the provider
	// does not support reinstallation, the function should return an error
	// stating this. If reinstalled, the installed tag should be updated to
	// allow the reconcile loop to restart the takeover process.
	ReinstallMachine(context.Context, ProviderID) error
}