open-consul/consul/session_endpoint.go

191 lines
5.4 KiB
Go

package consul
import (
"fmt"
"time"
"github.com/armon/go-metrics"
"github.com/hashicorp/consul/consul/structs"
)
// Session endpoint is used to manipulate sessions for KV
type Session struct {
srv *Server
}
// Apply is used to apply a modifying request to the data store. This should
// only be used for operations that modify the data
func (s *Session) Apply(args *structs.SessionRequest, reply *string) error {
if done, err := s.srv.forward("Session.Apply", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"consul", "session", "apply"}, time.Now())
// Verify the args
if args.Session.ID == "" && args.Op == structs.SessionDestroy {
return fmt.Errorf("Must provide ID")
}
if args.Session.Node == "" && args.Op == structs.SessionCreate {
return fmt.Errorf("Must provide Node")
}
// Ensure that the specified behavior is allowed
switch args.Session.Behavior {
case "":
// Default behavior to Release for backwards compatibility
args.Session.Behavior = structs.SessionKeysRelease
case structs.SessionKeysRelease:
case structs.SessionKeysDelete:
default:
return fmt.Errorf("Invalid Behavior setting '%s'", args.Session.Behavior)
}
// Ensure the Session TTL is valid if provided
if args.Session.TTL != "" {
ttl, err := time.ParseDuration(args.Session.TTL)
if err != nil {
return fmt.Errorf("Session TTL '%s' invalid: %v", args.Session.TTL, err)
}
if ttl != 0 && (ttl < structs.SessionTTLMin || ttl > structs.SessionTTLMax) {
return fmt.Errorf("Invalid Session TTL '%d', must be between [%v=%v]",
ttl, structs.SessionTTLMin, structs.SessionTTLMax)
}
}
// If this is a create, we must generate the Session ID. This must
// be done prior to appending to the raft log, because the ID is not
// deterministic. Once the entry is in the log, the state update MUST
// be deterministic or the followers will not converge.
if args.Op == structs.SessionCreate {
// Generate a new session ID, verify uniqueness
state := s.srv.fsm.State()
for {
args.Session.ID = generateUUID()
_, sess, err := state.SessionGet(args.Session.ID)
if err != nil {
s.srv.logger.Printf("[ERR] consul.session: Session lookup failed: %v", err)
return err
}
if sess == nil {
break
}
}
}
// Apply the update
resp, err := s.srv.raftApply(structs.SessionRequestType, args)
if err != nil {
s.srv.logger.Printf("[ERR] consul.session: Apply failed: %v", err)
return err
}
if args.Op == structs.SessionCreate && args.Session.TTL != "" {
// If we created a session with a TTL, reset the expiration timer
s.srv.resetSessionTimer(args.Session.ID, &args.Session)
} else if args.Op == structs.SessionDestroy {
// If we destroyed a session, it might potentially have a TTL,
// and we need to clear the timer
s.srv.clearSessionTimer(args.Session.ID)
}
if respErr, ok := resp.(error); ok {
return respErr
}
// Check if the return type is a string
if respString, ok := resp.(string); ok {
*reply = respString
}
return nil
}
// Get is used to retrieve a single session
func (s *Session) Get(args *structs.SessionSpecificRequest,
reply *structs.IndexedSessions) error {
if done, err := s.srv.forward("Session.Get", args, args, reply); done {
return err
}
// Get the local state
state := s.srv.fsm.State()
return s.srv.blockingRPC(&args.QueryOptions,
&reply.QueryMeta,
state.QueryTables("SessionGet"),
func() error {
index, session, err := state.SessionGet(args.Session)
reply.Index = index
if session != nil {
reply.Sessions = structs.Sessions{session}
} else {
reply.Sessions = nil
}
return err
})
}
// List is used to list all the active sessions
func (s *Session) List(args *structs.DCSpecificRequest,
reply *structs.IndexedSessions) error {
if done, err := s.srv.forward("Session.List", args, args, reply); done {
return err
}
// Get the local state
state := s.srv.fsm.State()
return s.srv.blockingRPC(&args.QueryOptions,
&reply.QueryMeta,
state.QueryTables("SessionList"),
func() error {
var err error
reply.Index, reply.Sessions, err = state.SessionList()
return err
})
}
// NodeSessions is used to get all the sessions for a particular node
func (s *Session) NodeSessions(args *structs.NodeSpecificRequest,
reply *structs.IndexedSessions) error {
if done, err := s.srv.forward("Session.NodeSessions", args, args, reply); done {
return err
}
// Get the local state
state := s.srv.fsm.State()
return s.srv.blockingRPC(&args.QueryOptions,
&reply.QueryMeta,
state.QueryTables("NodeSessions"),
func() error {
var err error
reply.Index, reply.Sessions, err = state.NodeSessions(args.Node)
return err
})
}
// Renew is used to renew the TTL on a single session
func (s *Session) Renew(args *structs.SessionSpecificRequest,
reply *structs.IndexedSessions) error {
if done, err := s.srv.forward("Session.Renew", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"consul", "session", "renew"}, time.Now())
// Get the session, from local state
state := s.srv.fsm.State()
index, session, err := state.SessionGet(args.Session)
if err != nil {
return err
}
// Reset the session TTL timer
reply.Index = index
if session != nil {
reply.Sessions = structs.Sessions{session}
if err := s.srv.resetSessionTimer(args.Session, session); err != nil {
s.srv.logger.Printf("[ERR] consul.session: Session renew failed: %v", err)
return err
}
}
return nil
}