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/Makefile

@@ -0,0 +1,77 @@
+# 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.
+
+# Ensure GOBIN is not set during build so that promu is installed to the correct path
+unexport GOBIN
+
+GO           ?= go
+GOFMT        ?= $(GO)fmt
+FIRST_GOPATH := $(firstword $(subst :, ,$(shell $(GO) env GOPATH)))
+STATICCHECK  := $(FIRST_GOPATH)/bin/staticcheck
+pkgs          = $(shell $(GO) list ./... | grep -v /vendor/)
+
+PREFIX                  ?= $(shell pwd)
+BIN_DIR                 ?= $(shell pwd)
+
+ifdef DEBUG
+  bindata_flags = -debug
+endif
+
+STATICCHECK_IGNORE =
+
+all: format staticcheck build test
+
+style:
+	@echo ">> checking code style"
+	@! $(GOFMT) -d $(shell find . -path ./vendor -prune -o -name '*.go' -print) | grep '^'
+
+check_license:
+	@echo ">> checking license header"
+	@./scripts/check_license.sh
+
+test: fixtures/.unpacked sysfs/fixtures/.unpacked
+	@echo ">> running all tests"
+	@$(GO) test -race $(shell $(GO) list ./... | grep -v /vendor/ | grep -v examples)
+
+format:
+	@echo ">> formatting code"
+	@$(GO) fmt $(pkgs)
+
+vet:
+	@echo ">> vetting code"
+	@$(GO) vet $(pkgs)
+
+staticcheck: $(STATICCHECK)
+	@echo ">> running staticcheck"
+	@$(STATICCHECK) -ignore "$(STATICCHECK_IGNORE)" $(pkgs)
+
+%/.unpacked: %.ttar
+	./ttar -C $(dir $*) -x -f $*.ttar
+	touch $@
+
+update_fixtures: fixtures.ttar sysfs/fixtures.ttar
+
+%fixtures.ttar: %/fixtures
+	rm -v $(dir $*)fixtures/.unpacked
+	./ttar -C $(dir $*) -c -f $*fixtures.ttar fixtures/
+
+$(FIRST_GOPATH)/bin/staticcheck:
+	@GOOS= GOARCH= $(GO) get -u honnef.co/go/tools/cmd/staticcheck
+
+.PHONY: all style check_license format test vet staticcheck
+
+# Declaring the binaries at their default locations as PHONY targets is a hack
+# to ensure the latest version is downloaded on every make execution.
+# If this is not desired, copy/symlink these binaries to a different path and
+# set the respective environment variables.
+.PHONY: $(GOPATH)/bin/staticcheck