proxy

type Daemon struct {
	// Command is the command to execute to start this daemon. This must
	// be a Cmd that isn't yet started.
	Command *exec.Cmd

	// ProxyID is the ID of the proxy service. This is required for API
	// requests (along with the token) and is passed via env var.
	ProxyID string

	// ProxyToken is the special local-only ACL token that allows a proxy
	// to communicate to the Connect-specific endpoints.
	ProxyToken string

	// Logger is where logs will be sent around the management of this
	// daemon. The actual logs for the daemon itself will be sent to
	// a file.
	Logger *log.Logger

	// PidPath is the path where a pid file will be created storing the
	// pid of the active process. If this is empty then a pid-file won't
	// be created. Under erroneous conditions, the pid file may not be
	// created but the error will be logged to the Logger.
	PidPath string
	// contains filtered or unexported fields
}

type Manager struct {
	// State is the local state that is the source of truth for all
	// configured managed proxies.
	State *local.State

	// Logger is the logger for information about manager behavior.
	// Output for proxies will not go here generally but varies by proxy
	// implementation type.
	Logger *log.Logger

	// DataDir is the path to the directory where data for proxies is
	// written, including snapshots for any state changes in the manager.
	// Within the data dir, files will be written in the following locatins:
	//
	//   * logs/ - log files named <service id>-std{out|err}.log
	//   * pids/ - pid files for daemons named <service id>.pid
	//   * snapshot.json - the state of the manager
	//
	DataDir string

	// Extra environment variables to set for the proxies
	ProxyEnv []string

	// SnapshotPeriod is the duration between snapshots. This can be set
	// relatively low to ensure accuracy, because if the new snapshot matches
	// the last snapshot taken, no file will be written. Therefore, setting
	// this low causes only slight CPU/memory usage but doesn't result in
	// disk IO. If this isn't set, ManagerSnapshotPeriod will be the default.
	//
	// This only has an effect if snapshots are enabled (DataDir is set).
	SnapshotPeriod time.Duration

	// CoalescePeriod and QuiescencePeriod control the timers for coalescing
	// updates from the local state. See the defaults at the top of this
	// file for more documentation. These will be set to those defaults
	// by NewManager.
	CoalescePeriod  time.Duration
	QuiescentPeriod time.Duration

	// AllowRoot configures whether proxies can be executed as root (EUID == 0).
	// If this is false then the manager will run and proxies can be added
	// and removed but none will be started an errors will be logged
	// to the logger.
	AllowRoot bool
	// contains filtered or unexported fields
}

type Noop struct{}

type Proxy interface {
	// Start starts the proxy. If an error is returned then the managed
	// proxy registration is rejected. Therefore, this should only fail if
	// the configuration of the proxy itself is irrecoverable, and should
	// retry starting for other failures.
	//
	// Starting an already-started proxy should not return an error.
	Start() error

	// Stop stops the proxy and disallows it from ever being started again.
	// This should also clean up any resources used by this Proxy.
	//
	// If the proxy is not started yet, this should not return an error, but
	// it should disallow Start from working again. If the proxy is already
	// stopped, this should not return an error.
	Stop() error

	// Close should clean up any resources associated with this proxy but
	// keep it running in the background. Only one of Close or Stop can be
	// called.
	Close() error

	// Equal returns true if the argument is equal to the proxy being called.
	// This is called by the manager to determine if a change in configuration
	// results in a proxy that needs to be restarted or not. If Equal returns
	// false, then the manager will stop the old proxy and start the new one.
	// If Equal returns true, the old proxy will remain running and the new
	// one will be ignored.
	Equal(Proxy) bool

	// MarshalSnapshot returns the state that will be stored in a snapshot
	// so that Consul can recover the proxy process after a restart. The
	// result should only contain primitive values and containers (lists/maps).
	//
	// MarshalSnapshot does NOT need to store the following fields, since they
	// are part of the manager snapshot and will be automatically restored
	// for any proxies: proxy ID.
	//
	// UnmarshalSnapshot is called to restore the receiving Proxy from its
	// marshalled state. If UnmarshalSnapshot returns an error, the snapshot
	// is ignored and the marshalled snapshot will be lost. The manager will
	// log.
	//
	// This should save/restore enough state to be able to regain management
	// of a proxy process as well as to perform the Equal method above. The
	// Equal method will be called when a local state sync happens to determine
	// if the recovered process should be restarted or not.
	MarshalSnapshot() map[string]interface{}
	UnmarshalSnapshot(map[string]interface{}) error
}