merge master

Author: xiang90

Documentation/internal-protocol-versioning.md

@@ -4,9 +4,9 @@ Goal: We want to be able to upgrade an individual peer in an etcd cluster to a n
 The process will take the form of individual followers upgrading to the latest version until the entire cluster is on the new version.
 
 Immediate need: etcd is moving too fast to version the internal API right now.
-But, we need to keep mixed version clusters from being started by a rollowing upgrade process (e.g. the CoreOS developer alpha).
+But, we need to keep mixed version clusters from being started by a rolling upgrade process (e.g. the CoreOS developer alpha).
 
-Longer term need: Having a mixed version cluster where all peers are not be running the exact same version of etcd itself but are able to speak one version of the internal protocol.
+Longer term need: Having a mixed version cluster where all peers are not running the exact same version of etcd itself but are able to speak one version of the internal protocol.
 
 Solution: The internal protocol needs to be versioned just as the client protocol is.
 Initially during the 0.\*.\* series of etcd releases we won't allow mixed versions at all.

README.md

@@ -56,26 +56,26 @@ go version
 ```
 
 
-### Running a single node
+### Running a single machine
 
-These examples will use a single node cluster to show you the basics of the etcd REST API.
+These examples will use a single machine cluster to show you the basics of the etcd REST API.
 Let's start etcd:
 
 ```sh
-./etcd -data-dir node0 -name node0
+./etcd -data-dir machine0 -name machine0
 ```
 
-This will bring up an etcd node listening on port 4001 for client communication and on port 7001 for server-to-server communication.
-The `-data-dir node0` argument tells etcd to write node configuration, logs and snapshots to the `./node0/` directory.
-The `-name node0` tells the rest of the cluster that this node is named node0.
+This will bring up etcd listening on port 4001 for client communication and on port 7001 for server-to-server communication.
+The `-data-dir machine0` argument tells etcd to write machine configuration, logs and snapshots to the `./machine0/` directory.
+The `-name machine` tells the rest of the cluster that this machine is named machine0.
 
 
 
 ## Usage
 
 ### Setting the value to a key
 
-Let’s set the first key-value pair to the node.
+Let’s set the first key-value pair to the datastore.
 In this case the key is `/message` and the value is `Hello world`.
 
 ```sh
@@ -121,7 +121,7 @@ curl -L http://127.0.0.1:4001/v2/keys/message
 You can change the value of `/message` from `Hello world` to `Hello etcd` with another `PUT` request to the key:
 
 ```sh
-curl -L http://127.0.0.1:4001/v1/keys/message -XPUT -d value="Hello etcd"
+curl -L http://127.0.0.1:4001/v2/keys/message -XPUT -d value="Hello etcd"
 ```
 
 ```json
@@ -164,7 +164,7 @@ Note the two new fields in response:
 
 2. The `ttl` is the time to live for the key, in seconds.
 
-_NOTE_: Keys can only be expired by a cluster leader so if a node gets disconnected from the cluster, its keys will not expire until it rejoins.
+_NOTE_: Keys can only be expired by a cluster leader so if a machine gets disconnected from the cluster, its keys will not expire until it rejoins.
 
 Now you can try to get the key by sending a `GET` request:
 
@@ -219,9 +219,9 @@ The watch command returns immediately with the same response as previous.
 
 ### Atomic Compare-and-Swap (CAS)
 
-Etcd can be used as a centralized coordination service in a cluster and `CompareAndSwap` is the most basic operation to build distributed lock service. 
+Etcd can be used as a centralized coordination service in a cluster and `CompareAndSwap` is the most basic operation to build distributed lock service.
 
-This command will set the value of a key only if the client-provided conditions are equal to the current conditions. 
+This command will set the value of a key only if the client-provided conditions are equal to the current conditions.
 
 The current comparable conditions are:
 
@@ -235,14 +235,26 @@ Here is a simple example.
 Let's create a key-value pair first: `foo=one`.
 
 ```sh
-curl -L http://127.0.0.1:4001/v1/keys/foo -XPUT -d value=one
+curl -L http://127.0.0.1:4001/v2/keys/foo -XPUT -d value=one
 ```
 
-Let's try an invalid `CompareAndSwap` command first.
-We can provide the `prevValue` parameter to the set command to make it a `CompareAndSwap` command.
+Let's try some invalid `CompareAndSwap` commands first.
 
+Trying to set this existing key with `prevExist=false` fails as expected:
 ```sh
-curl -L http://127.0.0.1:4001/v1/keys/foo?prevValue=two -XPUT -d value=three
+curl -L http://127.0.0.1:4001/v2/keys/foo?prevExist=false -XPUT -d value=three
+```
+
+The error code explains the problem:
+
+```json
+{"errorCode":105,"message":"Already exists","cause":"/foo","index":39776}
+```
+
+Now lets provide a `prevValue` parameter:
+
+```sh
+curl -L http://127.0.0.1:4001/v2/keys/foo?prevValue=two -XPUT -d value=three
 ```
 
 This will try to compare the previous value of the key and the previous value we provided. If they are equal, the value of the key will change to three.
@@ -378,12 +390,12 @@ For testing you can use the certificates in the `fixtures/ca` directory.
 Let's configure etcd to use this keypair:
 
 ```sh
-./etcd -f -name node0 -data-dir node0 -cert-file=./fixtures/ca/server.crt -key-file=./fixtures/ca/server.key.insecure
+./etcd -f -name machine0 -data-dir machine0 -cert-file=./fixtures/ca/server.crt -key-file=./fixtures/ca/server.key.insecure
 ```
 
 There are a few new options we're using:
 
-* `-f` - forces a new node configuration, even if an existing configuration is found. (WARNING: data loss!)
+* `-f` - forces a new machine configuration, even if an existing configuration is found. (WARNING: data loss!)
 * `-cert-file` and `-key-file` specify the location of the cert and key files to be used for for transport layer security between the client and server.
 
 You can now test the configuration using HTTPS:
@@ -413,7 +425,7 @@ We can also do authentication using CA certs.
 The clients will provide their cert to the server and the server will check whether the cert is signed by the CA and decide whether to serve the request.
 
 ```sh
-./etcd -f -name node0 -data-dir node0 -ca-file=./fixtures/ca/ca.crt -cert-file=./fixtures/ca/server.crt -key-file=./fixtures/ca/server.key.insecure
+./etcd -f -name machine0 -data-dir machine0 -ca-file=./fixtures/ca/ca.crt -cert-file=./fixtures/ca/server.crt -key-file=./fixtures/ca/server.key.insecure
 ```
 
 ```-ca-file``` is the path to the CA cert.
@@ -435,7 +447,7 @@ routines:SSL3_READ_BYTES:sslv3 alert bad certificate
 We need to give the CA signed cert to the server.
 
 ```sh
-curl --key ./fixtures/ca/server2.key.insecure --cert ./fixtures/ca/server2.crt --cacert ./fixtures/ca/server-chain.pem -L https://127.0.0.1:4001/v1/keys/foo -XPUT -d value=bar -v
+curl --key ./fixtures/ca/server2.key.insecure --cert ./fixtures/ca/server2.crt --cacert ./fixtures/ca/server-chain.pem -L https://127.0.0.1:4001/v2/keys/foo -XPUT -d value=bar -v
 ```
 
 You should able to see:
@@ -463,29 +475,29 @@ We use Raft as the underlying distributed protocol which provides consistency an
 
 Let start by creating 3 new etcd instances.
 
-We use `-peer-addr` to specify server port and `-addr` to specify client port and `-data-dir` to specify the directory to store the log and info of the node in the cluster:
+We use `-peer-addr` to specify server port and `-addr` to specify client port and `-data-dir` to specify the directory to store the log and info of the machine in the cluster:
 
 ```sh
-./etcd -peer-addr 127.0.0.1:7001 -addr 127.0.0.1:4001 -data-dir nodes/node1 -name node1
+./etcd -peer-addr 127.0.0.1:7001 -addr 127.0.0.1:4001 -data-dir machines/machine1 -name machine1
 ```
 
 **Note:** If you want to run etcd on an external IP address and still have access locally, you'll need to add `-bind-addr 0.0.0.0` so that it will listen on both external and localhost addresses.
 A similar argument `-peer-bind-addr` is used to setup the listening address for the server port.
 
-Let's join two more nodes to this cluster using the `-peers` argument:
+Let's join two more machines to this cluster using the `-peers` argument:
 
 ```sh
-./etcd -peer-addr 127.0.0.1:7002 -addr 127.0.0.1:4002 -peers 127.0.0.1:7001 -data-dir nodes/node2 -name node2
-./etcd -peer-addr 127.0.0.1:7003 -addr 127.0.0.1:4003 -peers 127.0.0.1:7001 -data-dir nodes/node3 -name node3
+./etcd -peer-addr 127.0.0.1:7002 -addr 127.0.0.1:4002 -peers 127.0.0.1:7001 -data-dir machines/machine2 -name machine2
+./etcd -peer-addr 127.0.0.1:7003 -addr 127.0.0.1:4003 -peers 127.0.0.1:7001 -data-dir machines/machine3 -name machine3
 ```
 
 We can retrieve a list of machines in the cluster using the HTTP API:
 
 ```sh
-curl -L http://127.0.0.1:4001/v1/machines
+curl -L http://127.0.0.1:4001/v2/machines
 ```
 
-We should see there are three nodes in the cluster
+We should see there are three machines in the cluster
 
 ```
 http://127.0.0.1:4001, http://127.0.0.1:4002, http://127.0.0.1:4003
@@ -494,11 +506,11 @@ http://127.0.0.1:4001, http://127.0.0.1:4002, http://127.0.0.1:4003
 The machine list is also available via the main key API:
 
 ```sh
-curl -L http://127.0.0.1:4001/v1/keys/_etcd/machines
+curl -L http://127.0.0.1:4001/v2/keys/_etcd/machines
 ```
 
 ```json
-[{"action":"get","key":"/_etcd/machines/node1","value":"raft=http://127.0.0.1:7001\u0026etcd=http://127.0.0.1:4001","index":1},{"action":"get","key":"/_etcd/machines/node2","value":"raft=http://127.0.0.1:7002\u0026etcd=http://127.0.0.1:4002","index":1},{"action":"get","key":"/_etcd/machines/node3","value":"raft=http://127.0.0.1:7003\u0026etcd=http://127.0.0.1:4003","index":1}]
+[{"action":"get","key":"/_etcd/machines/machine1","value":"raft=http://127.0.0.1:7001\u0026etcd=http://127.0.0.1:4001","index":1},{"action":"get","key":"/_etcd/machines/machine2","value":"raft=http://127.0.0.1:7002\u0026etcd=http://127.0.0.1:4002","index":1},{"action":"get","key":"/_etcd/machines/machine3","value":"raft=http://127.0.0.1:7003\u0026etcd=http://127.0.0.1:4003","index":1}]
 ```
 
 We can also get the current leader in the cluster:
@@ -529,13 +541,13 @@ curl -L http://127.0.0.1:4001/v2/keys/foo -XPUT -d value=bar
 Now if we kill the leader of the cluster, we can get the value from one of the other two machines:
 
 ```sh
-curl -L http://127.0.0.1:4002/v1/keys/foo
+curl -L http://127.0.0.1:4002/v2/keys/foo
 ```
 
 We can also see that a new leader has been elected:
 
 ```
-curl -L http://127.0.0.1:4002/v1/leader
+curl -L http://127.0.0.1:4002/v2/leader
 ```
 
 ```
@@ -551,13 +563,13 @@ http://127.0.0.1:7003
 
 ### Testing Persistence
 
-Next we'll kill all the nodes to test persistence.
-Type `CTRL-C` on each terminal and then rerun the same command you used to start each node.
+Next we'll kill all the machines to test persistence.
+Type `CTRL-C` on each terminal and then rerun the same command you used to start each machine.
 
 Your request for the `foo` key will return the correct value:
 
 ```sh
-curl -L http://127.0.0.1:4002/v1/keys/foo
+curl -L http://127.0.0.1:4002/v2/keys/foo
 ```
 
 ```json
@@ -654,8 +666,8 @@ The command is not committed until the majority of the cluster peers receive tha
 Because of this majority voting property, the ideal cluster should be kept small to keep speed up and be made up of an odd number of peers.
 
 Odd numbers are good because if you have 8 peers the majority will be 5 and if you have 9 peers the majority will still be 5.
-The result is that an 8 peer cluster can tolerate 3 peer failures and a 9 peer cluster can tolerate 4 nodes failures.
-And in the best case when all 9 peers are responding the cluster will perform at the speed of the fastest 5 nodes.
+The result is that an 8 peer cluster can tolerate 3 peer failures and a 9 peer cluster can tolerate 4 machine failures.
+And in the best case when all 9 peers are responding the cluster will perform at the speed of the fastest 5 machines.
 
 
 ### Why SSLv3 alert handshake failure when using SSL client auth?
@@ -677,7 +689,7 @@ Add the following section to your openssl.cnf:
 When creating the cert be sure to reference it in the `-extensions` flag:
 
 ```
-openssl ca -config openssl.cnf -policy policy_anything -extensions ssl_client -out certs/node.crt -infiles node.csr
+openssl ca -config openssl.cnf -policy policy_anything -extensions ssl_client -out certs/machine.crt -infiles machine.csr
 ```
 
 

error/error.go

@@ -32,6 +32,7 @@ const (
 	EcodeNotDir         = 104
 	EcodeNodeExist      = 105
 	EcodeKeyIsPreserved = 106
+	EcodeRootROnly      = 107
 
 	EcodeValueRequired      = 200
 	EcodePrevValueRequired  = 201
@@ -56,6 +57,7 @@ func init() {
 	errors[EcodeNoMorePeer] = "Reached the max number of peers in the cluster"
 	errors[EcodeNotDir] = "Not A Directory"
 	errors[EcodeNodeExist] = "Already exists" // create
+	errors[EcodeRootROnly] = "Root is read only"
 	errors[EcodeKeyIsPreserved] = "The prefix of given key is a keyword in etcd"
 
 	// Post form related errors

server/server.go

@@ -96,6 +96,11 @@ func (s *Server) PeerURL(name string) (string, bool) {
 	return s.registry.PeerURL(name)
 }
 
+// ClientURL retrieves the Client URL for a given node name.
+func (s *Server) ClientURL(name string) (string, bool) {
+	return s.registry.ClientURL(name)
+}
+
 // Returns a reference to the Store.
 func (s *Server) Store() store.Store {
 	return s.store

server/usage.go

@@ -26,8 +26,9 @@ Options:
   -vv               Enabled very verbose logging.
 
 Cluster Configuration Options:
-  -peers=<peers>      Comma-separated list of peers (ip + port) in the cluster.
-  -peers-file=<path>  Path to a file containing the peer list.
+  -peers-file=<path>              Path to a file containing the peer list.
+  -peers=<host:port>,<host:port>  Comma-separated list of peers. The members
+                                  should match the peer's '-peer-addr' flag.
 
 Client Communication Options:
   -addr=<host:port>   The public host:port used for client communication.

server/v2/get_handler.go

@@ -23,7 +23,7 @@ func GetHandler(w http.ResponseWriter, req *http.Request, s Server) error {
 	// Help client to redirect the request to the current leader
 	if req.FormValue("consistent") == "true" && s.State() != raft.Leader {
 		leader := s.Leader()
-		hostname, _ := s.PeerURL(leader)
+		hostname, _ := s.ClientURL(leader)
 		url := hostname + req.URL.Path
 		log.Debugf("Redirect consistent get to %s", url)
 		http.Redirect(w, req, url, http.StatusTemporaryRedirect)

server/v2/v2.go

@@ -13,6 +13,7 @@ type Server interface {
 	CommitIndex() uint64
 	Term() uint64
 	PeerURL(string) (string, bool)
+	ClientURL(string) (string, bool)
 	Store() store.Store
 	Dispatch(raft.Command, http.ResponseWriter, *http.Request) error
 }

store/event_history.go

@@ -2,6 +2,7 @@ package store
 
 import (
 	"fmt"
+	"path"
 	"strings"
 	"sync"
 
@@ -39,8 +40,8 @@ func (eh *EventHistory) addEvent(e *Event) *Event {
 }
 
 // scan function is enumerating events from the index in history and
-// stops till the first point where the key has identified prefix
-func (eh *EventHistory) scan(prefix string, index uint64) (*Event, *etcdErr.Error) {
+// stops till the first point where the key has identified key
+func (eh *EventHistory) scan(key string, recursive bool, index uint64) (*Event, *etcdErr.Error) {
 	eh.rwl.RLock()
 	defer eh.rwl.RUnlock()
 
@@ -62,7 +63,19 @@ func (eh *EventHistory) scan(prefix string, index uint64) (*Event, *etcdErr.Erro
 	for {
 		e := eh.Queue.Events[i]
 
-		if strings.HasPrefix(e.Node.Key, prefix) && index <= e.Index() { // make sure we bypass the smaller one
+		ok := (e.Node.Key == key)
+
+		if recursive {
+			// add tailing slash
+			key := path.Clean(key)
+			if key[len(key)-1] != '/' {
+				key = key + "/"
+			}
+
+			ok = ok || strings.HasPrefix(e.Node.Key, key)
+		}
+
+		if ok && index <= e.Index() { // make sure we bypass the smaller one
 			return e, nil
 		}
 

store/event_test.go

@@ -41,24 +41,24 @@ func TestScanHistory(t *testing.T) {
 	eh.addEvent(newEvent(Create, "/foo/bar/bar", 4, 4))
 	eh.addEvent(newEvent(Create, "/foo/foo/foo", 5, 5))
 
-	e, err := eh.scan("/foo", 1)
+	e, err := eh.scan("/foo", false, 1)
 	if err != nil || e.Index() != 1 {
 		t.Fatalf("scan error [/foo] [1] %v", e.Index)
 	}
 
-	e, err = eh.scan("/foo/bar", 1)
+	e, err = eh.scan("/foo/bar", false, 1)
 
 	if err != nil || e.Index() != 2 {
 		t.Fatalf("scan error [/foo/bar] [2] %v", e.Index)
 	}
 
-	e, err = eh.scan("/foo/bar", 3)
+	e, err = eh.scan("/foo/bar", true, 3)
 
 	if err != nil || e.Index() != 4 {
 		t.Fatalf("scan error [/foo/bar/bar] [4] %v", e.Index)
 	}
 
-	e, err = eh.scan("/foo/bar", 6)
+	e, err = eh.scan("/foo/bar", true, 6)
 
 	if e != nil {
 		t.Fatalf("bad index shoud reuturn nil")