agent

type AgentConfigParams struct {
	DataDir        string
	Tag            string
	Password       string
	Nonce          string
	StateAddresses []string
	APIAddresses   []string
	CACert         []byte
}

type Config interface {
	// DataDir returns the data directory. Each agent has a subdirectory
	// containing the configuration files.
	DataDir() string

	// Tag returns the tag of the entity on whose behalf the state connection
	// will be made.
	Tag() string

	// Dir returns the agent's directory.
	Dir() string

	// Nonce returns the nonce saved when the machine was provisioned
	// TODO: make this one of the key/value pairs.
	Nonce() string

	// CACert returns the CA certificate that is used to validate the state or
	// API servier's certificate.
	CACert() []byte

	// OpenAPI tries to connect to an API end-point.  If a non-empty
	// newPassword is returned, the password used to connect to the state
	// should be changed accordingly - the caller should set the entity's
	// password accordingly.
	OpenAPI(dialOpts api.DialOpts) (st *api.State, newPassword string, err error)

	// OpenState tries to open a direct connection to the state database using
	// the given Conf.
	OpenState() (*state.State, error)

	// Write writes the agent configuration.
	Write() error

	// WriteCommands returns shell commands to write the agent configuration.
	// It returns an error if the configuration does not have all the right
	// elements.
	WriteCommands() ([]string, error)

	// GenerateNewPassword creates a new random password and saves this.  The
	// new password string is returned.
	GenerateNewPassword() (string, error)

	// PasswordHash returns a hash of the password that is stored for state and
	// api connections.
	PasswordHash() string

	// APIServerDetails returns the details needed to run an API server.
	APIServerDetails() (port int, cert, key []byte)
}

type StateMachineConfigParams struct {
	AgentConfigParams
	StateServerCert []byte
	StateServerKey  []byte
	StatePort       int
	APIPort         int
}