func parseCompare(line string) (*clientv3.Cmp, error) {
var (
key string
op string
val string
)
lparenSplit := strings.SplitN(line, "(", 2)
if len(lparenSplit) != 2 {
return nil, fmt.Errorf("malformed comparison: %s", line)
}
target := lparenSplit[0]
n, serr := fmt.Sscanf(lparenSplit[1], "%q) %s %q", &key, &op, &val)
if n != 3 {
return nil, fmt.Errorf("malformed comparison: %s; got %s(%q) %s %q", line, target, key, op, val)
}
if serr != nil {
return nil, fmt.Errorf("malformed comparison: %s (%v)", line, serr)
}
var (
v int64
err error
cmp clientv3.Cmp
)
switch target {
case "ver", "version":
if v, err = strconv.ParseInt(val, 10, 64); err == nil {
cmp = clientv3.Compare(clientv3.Version(key), op, v)
}
case "c", "create":
if v, err = strconv.ParseInt(val, 10, 64); err == nil {
cmp = clientv3.Compare(clientv3.CreateRevision(key), op, v)
}
case "m", "mod":
if v, err = strconv.ParseInt(val, 10, 64); err == nil {
cmp = clientv3.Compare(clientv3.ModRevision(key), op, v)
}
case "val", "value":
cmp = clientv3.Compare(clientv3.Value(key), op, val)
default:
return nil, fmt.Errorf("malformed comparison: %s (unknown target %s)", line, target)
}
if err != nil {
return nil, fmt.Errorf("invalid txn compare request: %s", line)
}
return &cmp, nil
}
func (b *blockEtcd) Unlock() error {
vid := uint64(b.vid)
k := etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "blocklock")
tx := b.Etcd.Client.Txn(b.getContext()).If(
etcdv3.Compare(etcdv3.Version(k), ">", 0),
etcdv3.Compare(etcdv3.Value(k), "=", b.Etcd.UUID()),
).Then(
etcdv3.OpDelete(etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "blocklock")),
)
resp, err := tx.Commit()
if err != nil {
return err
}
if !resp.Succeeded {
return torus.ErrLocked
}
return nil
}
func (b *blockEtcd) SyncINode(inode torus.INodeRef) error {
vid := uint64(inode.Volume())
inodeBytes := string(inode.ToBytes())
k := etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "blocklock")
tx := b.Etcd.Client.Txn(b.getContext()).If(
etcdv3.Compare(etcdv3.Version(k), ">", 0),
etcdv3.Compare(etcdv3.Value(k), "=", b.Etcd.UUID()),
).Then(
etcdv3.OpPut(etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "blockinode"), inodeBytes),
)
resp, err := tx.Commit()
if err != nil {
return err
}
if !resp.Succeeded {
return torus.ErrLocked
}
return nil
}
func cas(key, value, newValue string, kvc clientv3.KV) error {
ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
tnxRes, err := kvc.Txn(ctx).
If(clientv3.Compare(clientv3.Value(key), "=", value)).
Then(clientv3.OpPut(key, newValue)).
Else(clientv3.OpGet(key)).
Commit()
cancel()
if err != nil {
return err
}
if tnxRes.Succeeded {
return nil
}
log.Println(string(tnxRes.Responses[0].GetResponseRange().Kvs[0].Value))
return errors.New("release error")
}
func ExampleKV_txn() {
cli, err := clientv3.New(clientv3.Config{
Endpoints: endpoints,
DialTimeout: dialTimeout,
})
if err != nil {
log.Fatal(err)
}
defer cli.Close()
kvc := clientv3.NewKV(cli)
_, err = kvc.Put(context.TODO(), "key", "xyz")
if err != nil {
log.Fatal(err)
}
ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
_, err = kvc.Txn(ctx).
If(clientv3.Compare(clientv3.Value("key"), ">", "abc")). // txn value comparisons are lexical
Then(clientv3.OpPut("key", "XYZ")). // this runs, since 'xyz' > 'abc'
Else(clientv3.OpPut("key", "ABC")).
Commit()
cancel()
if err != nil {
log.Fatal(err)
}
gresp, err := kvc.Get(context.TODO(), "key")
cancel()
if err != nil {
log.Fatal(err)
}
for _, ev := range gresp.Kvs {
fmt.Printf("%s : %s\n", ev.Key, ev.Value)
}
// key : XYZ
}
func ExampleAuth() {
cli, err := clientv3.New(clientv3.Config{
Endpoints: endpoints,
DialTimeout: dialTimeout,
})
if err != nil {
log.Fatal(err)
}
defer cli.Close()
if _, err = cli.RoleAdd(context.TODO(), "root"); err != nil {
log.Fatal(err)
}
if _, err = cli.UserAdd(context.TODO(), "root", "123"); err != nil {
log.Fatal(err)
}
if _, err = cli.UserGrantRole(context.TODO(), "root", "root"); err != nil {
log.Fatal(err)
}
if _, err = cli.RoleAdd(context.TODO(), "r"); err != nil {
log.Fatal(err)
}
if _, err = cli.RoleGrantPermission(
context.TODO(),
"r", // role name
"foo", // key
"zoo", // range end
clientv3.PermissionType(clientv3.PermReadWrite),
); err != nil {
log.Fatal(err)
}
if _, err = cli.UserAdd(context.TODO(), "u", "123"); err != nil {
log.Fatal(err)
}
if _, err = cli.UserGrantRole(context.TODO(), "u", "r"); err != nil {
log.Fatal(err)
}
if _, err = cli.AuthEnable(context.TODO()); err != nil {
log.Fatal(err)
}
cliAuth, err := clientv3.New(clientv3.Config{
Endpoints: endpoints,
DialTimeout: dialTimeout,
Username: "******",
Password: "******",
})
if err != nil {
log.Fatal(err)
}
defer cliAuth.Close()
if _, err = cliAuth.Put(context.TODO(), "foo1", "bar"); err != nil {
log.Fatal(err)
}
_, err = cliAuth.Txn(context.TODO()).
If(clientv3.Compare(clientv3.Value("zoo1"), ">", "abc")).
Then(clientv3.OpPut("zoo1", "XYZ")).
Else(clientv3.OpPut("zoo1", "ABC")).
Commit()
fmt.Println(err)
// now check the permission with the root account
rootCli, err := clientv3.New(clientv3.Config{
Endpoints: endpoints,
DialTimeout: dialTimeout,
Username: "******",
Password: "******",
})
if err != nil {
log.Fatal(err)
}
defer rootCli.Close()
resp, err := rootCli.RoleGet(context.TODO(), "r")
if err != nil {
log.Fatal(err)
}
fmt.Printf("user u permission: key %q, range end %q\n", resp.Perm[0].Key, resp.Perm[0].RangeEnd)
if _, err = rootCli.AuthDisable(context.TODO()); err != nil {
log.Fatal(err)
}
// Output: etcdserver: permission denied
// user u permission: key "foo", range end "zoo"
}