services/device/doc.go

// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package device defines interfaces for configuration of the Vanadium device
// manager.  The subdirectories implement the v.io/v23/services/device
// interfaces.
//
// The device manager is a server that is expected to run on every
// Vanadium-enabled device, and it handles both device management and management
// of the applications running on the device.
//
// The device manager is responsible for installing, updating, and launching
// applications.  It therefore sets up a footprint on the local filesystem, both
// to maintain its internal state, and to provide applications with their own
// private workspaces.
//
// The device manager is responsible for updating itself.  The mechanism to do
// so is implementation-dependent, though each device manager expects to be
// supplied with the file path of a symbolic link file, which the device manager
// will then update to point to the updated version of itself before terminating
// itself.  The device manager should therefore be launched via this symbolic
// link to enable auto-updates.  To enable updates, in addition to the symbolic
// link path, the device manager needs to be told what its application metadata
// is (such as command-line arguments and environment variables, i.e. the
// application envelope defined in the v.io/v23/services/application package),
// as well as the object name for where it can fetch an updated envelope, and
// the local filesystem path for its previous version (for rollbacks).
//
// Finally, the device manager needs to know its own object name, so it can pass
// that along to the applications that it starts.
//
// The impl subpackage contains the implementation of the device manager
// service.
//
// The config subpackage encapsulates the configuration settings that form the
// device manager service's 'contract' with its environment.
//
// The deviced subpackage contains the main driver.
package device