Add Generic Controller Related Metrics

To enhance operatability for the service using norman framework,
It's better to expose internal state as detail as possible.
This is the just starting point but at least which handler is executed
often and which handler with which key's execution is often failed
metrics is very useful to spot the place operator have to dig in when
something happened.
So this commit added 2 metrics.
1: handler execution total count
2: handler execution failure total count

vendor/github.com/prometheus/procfs/xfrm.go

@@ -0,0 +1,187 @@
+// Copyright 2017 Prometheus Team
+// 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 procfs
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// XfrmStat models the contents of /proc/net/xfrm_stat.
+type XfrmStat struct {
+	// All errors which are not matched by other
+	XfrmInError int
+	// No buffer is left
+	XfrmInBufferError int
+	// Header Error
+	XfrmInHdrError int
+	// No state found
+	// i.e. either inbound SPI, address, or IPSEC protocol at SA is wrong
+	XfrmInNoStates int
+	// Transformation protocol specific error
+	// e.g. SA Key is wrong
+	XfrmInStateProtoError int
+	// Transformation mode specific error
+	XfrmInStateModeError int
+	// Sequence error
+	// e.g. sequence number is out of window
+	XfrmInStateSeqError int
+	// State is expired
+	XfrmInStateExpired int
+	// State has mismatch option
+	// e.g. UDP encapsulation type is mismatched
+	XfrmInStateMismatch int
+	// State is invalid
+	XfrmInStateInvalid int
+	// No matching template for states
+	// e.g. Inbound SAs are correct but SP rule is wrong
+	XfrmInTmplMismatch int
+	// No policy is found for states
+	// e.g. Inbound SAs are correct but no SP is found
+	XfrmInNoPols int
+	// Policy discards
+	XfrmInPolBlock int
+	// Policy error
+	XfrmInPolError int
+	// All errors which are not matched by others
+	XfrmOutError int
+	// Bundle generation error
+	XfrmOutBundleGenError int
+	// Bundle check error
+	XfrmOutBundleCheckError int
+	// No state was found
+	XfrmOutNoStates int
+	// Transformation protocol specific error
+	XfrmOutStateProtoError int
+	// Transportation mode specific error
+	XfrmOutStateModeError int
+	// Sequence error
+	// i.e sequence number overflow
+	XfrmOutStateSeqError int
+	// State is expired
+	XfrmOutStateExpired int
+	// Policy discads
+	XfrmOutPolBlock int
+	// Policy is dead
+	XfrmOutPolDead int
+	// Policy Error
+	XfrmOutPolError     int
+	XfrmFwdHdrError     int
+	XfrmOutStateInvalid int
+	XfrmAcquireError    int
+}
+
+// NewXfrmStat reads the xfrm_stat statistics.
+func NewXfrmStat() (XfrmStat, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return XfrmStat{}, err
+	}
+
+	return fs.NewXfrmStat()
+}
+
+// NewXfrmStat reads the xfrm_stat statistics from the 'proc' filesystem.
+func (fs FS) NewXfrmStat() (XfrmStat, error) {
+	file, err := os.Open(fs.Path("net/xfrm_stat"))
+	if err != nil {
+		return XfrmStat{}, err
+	}
+	defer file.Close()
+
+	var (
+		x = XfrmStat{}
+		s = bufio.NewScanner(file)
+	)
+
+	for s.Scan() {
+		fields := strings.Fields(s.Text())
+
+		if len(fields) != 2 {
+			return XfrmStat{}, fmt.Errorf(
+				"couldn't parse %s line %s", file.Name(), s.Text())
+		}
+
+		name := fields[0]
+		value, err := strconv.Atoi(fields[1])
+		if err != nil {
+			return XfrmStat{}, err
+		}
+
+		switch name {
+		case "XfrmInError":
+			x.XfrmInError = value
+		case "XfrmInBufferError":
+			x.XfrmInBufferError = value
+		case "XfrmInHdrError":
+			x.XfrmInHdrError = value
+		case "XfrmInNoStates":
+			x.XfrmInNoStates = value
+		case "XfrmInStateProtoError":
+			x.XfrmInStateProtoError = value
+		case "XfrmInStateModeError":
+			x.XfrmInStateModeError = value
+		case "XfrmInStateSeqError":
+			x.XfrmInStateSeqError = value
+		case "XfrmInStateExpired":
+			x.XfrmInStateExpired = value
+		case "XfrmInStateInvalid":
+			x.XfrmInStateInvalid = value
+		case "XfrmInTmplMismatch":
+			x.XfrmInTmplMismatch = value
+		case "XfrmInNoPols":
+			x.XfrmInNoPols = value
+		case "XfrmInPolBlock":
+			x.XfrmInPolBlock = value
+		case "XfrmInPolError":
+			x.XfrmInPolError = value
+		case "XfrmOutError":
+			x.XfrmOutError = value
+		case "XfrmInStateMismatch":
+			x.XfrmInStateMismatch = value
+		case "XfrmOutBundleGenError":
+			x.XfrmOutBundleGenError = value
+		case "XfrmOutBundleCheckError":
+			x.XfrmOutBundleCheckError = value
+		case "XfrmOutNoStates":
+			x.XfrmOutNoStates = value
+		case "XfrmOutStateProtoError":
+			x.XfrmOutStateProtoError = value
+		case "XfrmOutStateModeError":
+			x.XfrmOutStateModeError = value
+		case "XfrmOutStateSeqError":
+			x.XfrmOutStateSeqError = value
+		case "XfrmOutStateExpired":
+			x.XfrmOutStateExpired = value
+		case "XfrmOutPolBlock":
+			x.XfrmOutPolBlock = value
+		case "XfrmOutPolDead":
+			x.XfrmOutPolDead = value
+		case "XfrmOutPolError":
+			x.XfrmOutPolError = value
+		case "XfrmFwdHdrError":
+			x.XfrmFwdHdrError = value
+		case "XfrmOutStateInvalid":
+			x.XfrmOutStateInvalid = value
+		case "XfrmAcquireError":
+			x.XfrmAcquireError = value
+		}
+
+	}
+
+	return x, s.Err()
+}