open-consul/consul/kvs_endpoint.go
2015-01-05 16:42:30 -08:00

211 lines
5.1 KiB
Go

package consul
import (
"fmt"
"time"
"github.com/armon/go-metrics"
"github.com/hashicorp/consul/consul/structs"
)
// KVS endpoint is used to manipulate the Key-Value store
type KVS struct {
srv *Server
}
// Apply is used to apply a KVS request to the data store. This should
// only be used for operations that modify the data
func (k *KVS) Apply(args *structs.KVSRequest, reply *bool) error {
if done, err := k.srv.forward("KVS.Apply", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"consul", "kvs", "apply"}, time.Now())
// Verify the args
if args.DirEnt.Key == "" && args.Op != structs.KVSDeleteTree {
return fmt.Errorf("Must provide key")
}
// Apply the ACL policy if any
acl, err := k.srv.resolveToken(args.Token)
if err != nil {
return err
} else if acl != nil {
switch args.Op {
case structs.KVSDeleteTree:
if !acl.KeyWritePrefix(args.DirEnt.Key) {
return permissionDeniedErr
}
default:
if !acl.KeyWrite(args.DirEnt.Key) {
return permissionDeniedErr
}
}
}
// If this is a lock, we must check for a lock-delay. Since lock-delay
// is based on wall-time, each peer expire the lock-delay at a slightly
// different time. This means the enforcement of lock-delay cannot be done
// after the raft log is committed as it would lead to inconsistent FSMs.
// Instead, the lock-delay must be enforced before commit. This means that
// only the wall-time of the leader node is used, preventing any inconsistencies.
if args.Op == structs.KVSLock {
state := k.srv.fsm.State()
expires := state.KVSLockDelay(args.DirEnt.Key)
if expires.After(time.Now()) {
k.srv.logger.Printf("[WARN] consul.kvs: Rejecting lock of %s due to lock-delay until %v",
args.DirEnt.Key, expires)
*reply = false
return nil
}
}
// Apply the update
resp, err := k.srv.raftApply(structs.KVSRequestType, args)
if err != nil {
k.srv.logger.Printf("[ERR] consul.kvs: Apply failed: %v", err)
return err
}
if respErr, ok := resp.(error); ok {
return respErr
}
// Check if the return type is a bool
if respBool, ok := resp.(bool); ok {
*reply = respBool
}
return nil
}
// Get is used to lookup a single key
func (k *KVS) Get(args *structs.KeyRequest, reply *structs.IndexedDirEntries) error {
if done, err := k.srv.forward("KVS.Get", args, args, reply); done {
return err
}
acl, err := k.srv.resolveToken(args.Token)
if err != nil {
return err
}
// Get the local state
state := k.srv.fsm.State()
opts := blockingRPCOptions{
queryOpts: &args.QueryOptions,
queryMeta: &reply.QueryMeta,
kvWatch: true,
kvPrefix: args.Key,
run: func() error {
index, ent, err := state.KVSGet(args.Key)
if err != nil {
return err
}
if acl != nil && !acl.KeyRead(args.Key) {
ent = nil
}
if ent == nil {
// Must provide non-zero index to prevent blocking
// Index 1 is impossible anyways (due to Raft internals)
if index == 0 {
reply.Index = 1
} else {
reply.Index = index
}
reply.Entries = nil
} else {
reply.Index = ent.ModifyIndex
reply.Entries = structs.DirEntries{ent}
}
return nil
},
}
return k.srv.blockingRPCOpt(&opts)
}
// List is used to list all keys with a given prefix
func (k *KVS) List(args *structs.KeyRequest, reply *structs.IndexedDirEntries) error {
if done, err := k.srv.forward("KVS.List", args, args, reply); done {
return err
}
acl, err := k.srv.resolveToken(args.Token)
if err != nil {
return err
}
// Get the local state
state := k.srv.fsm.State()
opts := blockingRPCOptions{
queryOpts: &args.QueryOptions,
queryMeta: &reply.QueryMeta,
kvWatch: true,
kvPrefix: args.Key,
run: func() error {
tombIndex, index, ent, err := state.KVSList(args.Key)
if err != nil {
return err
}
if acl != nil {
ent = FilterDirEnt(acl, ent)
}
if len(ent) == 0 {
// Must provide non-zero index to prevent blocking
// Index 1 is impossible anyways (due to Raft internals)
if index == 0 {
reply.Index = 1
} else {
reply.Index = index
}
} else {
// Determine the maximum affected index
var maxIndex uint64
for _, e := range ent {
if e.ModifyIndex > maxIndex {
maxIndex = e.ModifyIndex
}
}
if tombIndex > maxIndex {
maxIndex = tombIndex
}
reply.Index = maxIndex
reply.Entries = ent
}
return nil
},
}
return k.srv.blockingRPCOpt(&opts)
}
// ListKeys is used to list all keys with a given prefix to a seperator
func (k *KVS) ListKeys(args *structs.KeyListRequest, reply *structs.IndexedKeyList) error {
if done, err := k.srv.forward("KVS.ListKeys", args, args, reply); done {
return err
}
acl, err := k.srv.resolveToken(args.Token)
if err != nil {
return err
}
// Get the local state
state := k.srv.fsm.State()
opts := blockingRPCOptions{
queryOpts: &args.QueryOptions,
queryMeta: &reply.QueryMeta,
kvWatch: true,
kvPrefix: args.Prefix,
run: func() error {
index, keys, err := state.KVSListKeys(args.Prefix, args.Seperator)
reply.Index = index
if acl != nil {
keys = FilterKeys(acl, keys)
}
reply.Keys = keys
return err
},
}
return k.srv.blockingRPCOpt(&opts)
}