Prometheus endpoint (#5256)

* Add prometheus collector and route

* dep ensure -add github.com/prometheus/client_golang/prometheus

* dep ensure -update github.com/golang/protobuf

* add metrics to reserved usernames

* add comment head in metrics package

* fix style imports

* add metrics settings

* add bearer token check

* mapping metrics configs

* fix lint

* update config cheat sheet

* update conf sample, typo fix

vendor/github.com/prometheus/procfs/nfs/parse.go

@@ -0,0 +1,317 @@
+// Copyright 2018 The Prometheus Authors
+// 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 nfs
+
+import (
+	"fmt"
+)
+
+func parseReplyCache(v []uint64) (ReplyCache, error) {
+	if len(v) != 3 {
+		return ReplyCache{}, fmt.Errorf("invalid ReplyCache line %q", v)
+	}
+
+	return ReplyCache{
+		Hits:    v[0],
+		Misses:  v[1],
+		NoCache: v[2],
+	}, nil
+}
+
+func parseFileHandles(v []uint64) (FileHandles, error) {
+	if len(v) != 5 {
+		return FileHandles{}, fmt.Errorf("invalid FileHandles, line %q", v)
+	}
+
+	return FileHandles{
+		Stale:        v[0],
+		TotalLookups: v[1],
+		AnonLookups:  v[2],
+		DirNoCache:   v[3],
+		NoDirNoCache: v[4],
+	}, nil
+}
+
+func parseInputOutput(v []uint64) (InputOutput, error) {
+	if len(v) != 2 {
+		return InputOutput{}, fmt.Errorf("invalid InputOutput line %q", v)
+	}
+
+	return InputOutput{
+		Read:  v[0],
+		Write: v[1],
+	}, nil
+}
+
+func parseThreads(v []uint64) (Threads, error) {
+	if len(v) != 2 {
+		return Threads{}, fmt.Errorf("invalid Threads line %q", v)
+	}
+
+	return Threads{
+		Threads: v[0],
+		FullCnt: v[1],
+	}, nil
+}
+
+func parseReadAheadCache(v []uint64) (ReadAheadCache, error) {
+	if len(v) != 12 {
+		return ReadAheadCache{}, fmt.Errorf("invalid ReadAheadCache line %q", v)
+	}
+
+	return ReadAheadCache{
+		CacheSize:      v[0],
+		CacheHistogram: v[1:11],
+		NotFound:       v[11],
+	}, nil
+}
+
+func parseNetwork(v []uint64) (Network, error) {
+	if len(v) != 4 {
+		return Network{}, fmt.Errorf("invalid Network line %q", v)
+	}
+
+	return Network{
+		NetCount:   v[0],
+		UDPCount:   v[1],
+		TCPCount:   v[2],
+		TCPConnect: v[3],
+	}, nil
+}
+
+func parseServerRPC(v []uint64) (ServerRPC, error) {
+	if len(v) != 5 {
+		return ServerRPC{}, fmt.Errorf("invalid RPC line %q", v)
+	}
+
+	return ServerRPC{
+		RPCCount: v[0],
+		BadCnt:   v[1],
+		BadFmt:   v[2],
+		BadAuth:  v[3],
+		BadcInt:  v[4],
+	}, nil
+}
+
+func parseClientRPC(v []uint64) (ClientRPC, error) {
+	if len(v) != 3 {
+		return ClientRPC{}, fmt.Errorf("invalid RPC line %q", v)
+	}
+
+	return ClientRPC{
+		RPCCount:        v[0],
+		Retransmissions: v[1],
+		AuthRefreshes:   v[2],
+	}, nil
+}
+
+func parseV2Stats(v []uint64) (V2Stats, error) {
+	values := int(v[0])
+	if len(v[1:]) != values || values != 18 {
+		return V2Stats{}, fmt.Errorf("invalid V2Stats line %q", v)
+	}
+
+	return V2Stats{
+		Null:     v[1],
+		GetAttr:  v[2],
+		SetAttr:  v[3],
+		Root:     v[4],
+		Lookup:   v[5],
+		ReadLink: v[6],
+		Read:     v[7],
+		WrCache:  v[8],
+		Write:    v[9],
+		Create:   v[10],
+		Remove:   v[11],
+		Rename:   v[12],
+		Link:     v[13],
+		SymLink:  v[14],
+		MkDir:    v[15],
+		RmDir:    v[16],
+		ReadDir:  v[17],
+		FsStat:   v[18],
+	}, nil
+}
+
+func parseV3Stats(v []uint64) (V3Stats, error) {
+	values := int(v[0])
+	if len(v[1:]) != values || values != 22 {
+		return V3Stats{}, fmt.Errorf("invalid V3Stats line %q", v)
+	}
+
+	return V3Stats{
+		Null:        v[1],
+		GetAttr:     v[2],
+		SetAttr:     v[3],
+		Lookup:      v[4],
+		Access:      v[5],
+		ReadLink:    v[6],
+		Read:        v[7],
+		Write:       v[8],
+		Create:      v[9],
+		MkDir:       v[10],
+		SymLink:     v[11],
+		MkNod:       v[12],
+		Remove:      v[13],
+		RmDir:       v[14],
+		Rename:      v[15],
+		Link:        v[16],
+		ReadDir:     v[17],
+		ReadDirPlus: v[18],
+		FsStat:      v[19],
+		FsInfo:      v[20],
+		PathConf:    v[21],
+		Commit:      v[22],
+	}, nil
+}
+
+func parseClientV4Stats(v []uint64) (ClientV4Stats, error) {
+	values := int(v[0])
+	if len(v[1:]) != values {
+		return ClientV4Stats{}, fmt.Errorf("invalid ClientV4Stats line %q", v)
+	}
+
+	// This function currently supports mapping 59 NFS v4 client stats.  Older
+	// kernels may emit fewer stats, so we must detect this and pad out the
+	// values to match the expected slice size.
+	if values < 59 {
+		newValues := make([]uint64, 60)
+		copy(newValues, v)
+		v = newValues
+	}
+
+	return ClientV4Stats{
+		Null:               v[1],
+		Read:               v[2],
+		Write:              v[3],
+		Commit:             v[4],
+		Open:               v[5],
+		OpenConfirm:        v[6],
+		OpenNoattr:         v[7],
+		OpenDowngrade:      v[8],
+		Close:              v[9],
+		Setattr:            v[10],
+		FsInfo:             v[11],
+		Renew:              v[12],
+		SetClientID:        v[13],
+		SetClientIDConfirm: v[14],
+		Lock:               v[15],
+		Lockt:              v[16],
+		Locku:              v[17],
+		Access:             v[18],
+		Getattr:            v[19],
+		Lookup:             v[20],
+		LookupRoot:         v[21],
+		Remove:             v[22],
+		Rename:             v[23],
+		Link:               v[24],
+		Symlink:            v[25],
+		Create:             v[26],
+		Pathconf:           v[27],
+		StatFs:             v[28],
+		ReadLink:           v[29],
+		ReadDir:            v[30],
+		ServerCaps:         v[31],
+		DelegReturn:        v[32],
+		GetACL:             v[33],
+		SetACL:             v[34],
+		FsLocations:        v[35],
+		ReleaseLockowner:   v[36],
+		Secinfo:            v[37],
+		FsidPresent:        v[38],
+		ExchangeID:         v[39],
+		CreateSession:      v[40],
+		DestroySession:     v[41],
+		Sequence:           v[42],
+		GetLeaseTime:       v[43],
+		ReclaimComplete:    v[44],
+		LayoutGet:          v[45],
+		GetDeviceInfo:      v[46],
+		LayoutCommit:       v[47],
+		LayoutReturn:       v[48],
+		SecinfoNoName:      v[49],
+		TestStateID:        v[50],
+		FreeStateID:        v[51],
+		GetDeviceList:      v[52],
+		BindConnToSession:  v[53],
+		DestroyClientID:    v[54],
+		Seek:               v[55],
+		Allocate:           v[56],
+		DeAllocate:         v[57],
+		LayoutStats:        v[58],
+		Clone:              v[59],
+	}, nil
+}
+
+func parseServerV4Stats(v []uint64) (ServerV4Stats, error) {
+	values := int(v[0])
+	if len(v[1:]) != values || values != 2 {
+		return ServerV4Stats{}, fmt.Errorf("invalid V4Stats line %q", v)
+	}
+
+	return ServerV4Stats{
+		Null:     v[1],
+		Compound: v[2],
+	}, nil
+}
+
+func parseV4Ops(v []uint64) (V4Ops, error) {
+	values := int(v[0])
+	if len(v[1:]) != values || values < 39 {
+		return V4Ops{}, fmt.Errorf("invalid V4Ops line %q", v)
+	}
+
+	stats := V4Ops{
+		Op0Unused:    v[1],
+		Op1Unused:    v[2],
+		Op2Future:    v[3],
+		Access:       v[4],
+		Close:        v[5],
+		Commit:       v[6],
+		Create:       v[7],
+		DelegPurge:   v[8],
+		DelegReturn:  v[9],
+		GetAttr:      v[10],
+		GetFH:        v[11],
+		Link:         v[12],
+		Lock:         v[13],
+		Lockt:        v[14],
+		Locku:        v[15],
+		Lookup:       v[16],
+		LookupRoot:   v[17],
+		Nverify:      v[18],
+		Open:         v[19],
+		OpenAttr:     v[20],
+		OpenConfirm:  v[21],
+		OpenDgrd:     v[22],
+		PutFH:        v[23],
+		PutPubFH:     v[24],
+		PutRootFH:    v[25],
+		Read:         v[26],
+		ReadDir:      v[27],
+		ReadLink:     v[28],
+		Remove:       v[29],
+		Rename:       v[30],
+		Renew:        v[31],
+		RestoreFH:    v[32],
+		SaveFH:       v[33],
+		SecInfo:      v[34],
+		SetAttr:      v[35],
+		Verify:       v[36],
+		Write:        v[37],
+		RelLockOwner: v[38],
+	}
+
+	return stats, nil
+}