minio/cmd/rpc-common.go
Harshavardhana 1164fc60f3 Bring semantic versioning to provide for rolling upgrades (#5495)
This PR brings semver capabilities in our RPC layer to
ensure that we can upgrade the servers in rolling fashion
while keeping I/O in progress. This is only a framework change
the functionality remains the same as such and we do not
have any special API changes for now. But in future when
we bring in API changes we will be able to upgrade servers
without a downtime.

Additional change in this PR is to not abort when serverVersions
mismatch in a distributed cluster, instead wait for the quorum
treat the situation as if the server is down. This allows
for administrator to properly upgrade all the servers in the cluster.

Fixes #5393
2018-02-06 15:07:17 -08:00

152 lines
4.1 KiB
Go

/*
* Minio Cloud Storage, (C) 2016, 2017, 2018 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cmd
import (
"strconv"
"time"
"github.com/minio/dsync"
)
// Allow any RPC call request time should be no more/less than 3 seconds.
// 3 seconds is chosen arbitrarily.
const rpcSkewTimeAllowed = 3 * time.Second
func isRequestTimeAllowed(requestTime time.Time) bool {
// Check whether request time is within acceptable skew time.
utcNow := UTCNow()
return !(requestTime.Sub(utcNow) > rpcSkewTimeAllowed ||
utcNow.Sub(requestTime) > rpcSkewTimeAllowed)
}
// semVersion - RPC semantic versioning.
type semVersion struct {
Major uint64
Minor uint64
Patch uint64
}
// semver comparator implementation based on the semver 2.0.0 https://semver.org/.
func (v semVersion) Compare(o semVersion) int {
if v.Major != o.Major {
if v.Major > o.Major {
return 1
}
return -1
}
if v.Minor != o.Minor {
if v.Minor > o.Minor {
return 1
}
return -1
}
if v.Patch != o.Patch {
if v.Patch > o.Patch {
return 1
}
return -1
}
return 0
}
func (v semVersion) String() string {
b := make([]byte, 0, 5)
b = strconv.AppendUint(b, v.Major, 10)
b = append(b, '.')
b = strconv.AppendUint(b, v.Minor, 10)
b = append(b, '.')
b = strconv.AppendUint(b, v.Patch, 10)
return string(b)
}
// AuthRPCArgs represents minimum required arguments to make any authenticated RPC call.
type AuthRPCArgs struct {
// Authentication token to be verified by the server for every RPC call.
AuthToken string
Version semVersion
}
// SetAuthToken - sets the token to the supplied value.
func (args *AuthRPCArgs) SetAuthToken(authToken string) {
args.AuthToken = authToken
}
// SetRPCAPIVersion - sets the rpc version to the supplied value.
func (args *AuthRPCArgs) SetRPCAPIVersion(version semVersion) {
args.Version = version
}
// IsAuthenticated - validated whether this auth RPC args are already authenticated or not.
func (args AuthRPCArgs) IsAuthenticated() error {
// checks if rpc Version is not equal to current server rpc version.
// this is fine for now, but in future when we add backward compatible
// APIs we need to make sure to allow lesser versioned clients to
// talk over RPC, until then we are fine with this check.
if args.Version.Compare(globalRPCAPIVersion) != 0 {
return errRPCAPIVersionUnsupported
}
// Check whether the token is valid
if !isAuthTokenValid(args.AuthToken) {
return errInvalidToken
}
// Good to go.
return nil
}
// AuthRPCReply represents minimum required reply for any authenticated RPC call.
type AuthRPCReply struct{}
// LoginRPCArgs - login username and password for RPC.
type LoginRPCArgs struct {
AuthToken string
Version semVersion
RequestTime time.Time
}
// IsValid - validates whether this LoginRPCArgs are valid for authentication.
func (args LoginRPCArgs) IsValid() error {
// checks if rpc Version is not equal to current server rpc version.
// this is fine for now, but in future when we add backward compatible
// APIs we need to make sure to allow lesser versioned clients to
// talk over RPC, until then we are fine with this check.
if args.Version.Compare(globalRPCAPIVersion) != 0 {
return errRPCAPIVersionUnsupported
}
if !isRequestTimeAllowed(args.RequestTime) {
return errServerTimeMismatch
}
return nil
}
// LoginRPCReply - login reply is a dummy struct perhaps for future use.
type LoginRPCReply struct{}
// LockArgs represents arguments for any authenticated lock RPC call.
type LockArgs struct {
AuthRPCArgs
LockArgs dsync.LockArgs
}
func newLockArgs(args dsync.LockArgs) LockArgs {
return LockArgs{LockArgs: args}
}