[feature] Initial Prometheus metrics implementation (#2334)

* feat: Initial OTEL metrics

* docs: add metrics documentation

* fix: metrics endpoint conditional check

* feat: metrics endpoint basic auth

* fix: make metrics-auth-enabled default false

* fix: go fmt helpers.gen.go

* fix: add metric-related env vars to envparsing.sh

* fix: metrics docs

* fix: metrics related stuff in envparsing.sh

* fix: metrics docs

* chore: metrics docs wording

* fix: metrics stuff in envparsing?

* bump otel versions

---------

Co-authored-by: Tsuribori <user@acertaindebian>
Co-authored-by: Tsuribori <none@example.org>
Co-authored-by: tsmethurst <tobi.smethurst@protonmail.com>

1 files changed, 160 insertions, 0 deletions

diff --git a/vendor/github.com/prometheus/procfs/softirqs.go b/vendor/github.com/prometheus/procfs/softirqs.go
new file mode 100644
index 000000000..b8fad677d
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/softirqs.go
@@ -0,0 +1,160 @@
+// Copyright 2022 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 procfs
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+// Softirqs represents the softirq statistics.
+type Softirqs struct {
+	Hi      []uint64
+	Timer   []uint64
+	NetTx   []uint64
+	NetRx   []uint64
+	Block   []uint64
+	IRQPoll []uint64
+	Tasklet []uint64
+	Sched   []uint64
+	HRTimer []uint64
+	RCU     []uint64
+}
+
+func (fs FS) Softirqs() (Softirqs, error) {
+	fileName := fs.proc.Path("softirqs")
+	data, err := util.ReadFileNoStat(fileName)
+	if err != nil {
+		return Softirqs{}, err
+	}
+
+	reader := bytes.NewReader(data)
+
+	return parseSoftirqs(reader)
+}
+
+func parseSoftirqs(r io.Reader) (Softirqs, error) {
+	var (
+		softirqs = Softirqs{}
+		scanner  = bufio.NewScanner(r)
+	)
+
+	if !scanner.Scan() {
+		return Softirqs{}, fmt.Errorf("%w: softirqs empty", ErrFileRead)
+	}
+
+	for scanner.Scan() {
+		parts := strings.Fields(scanner.Text())
+		var err error
+
+		// require at least one cpu
+		if len(parts) < 2 {
+			continue
+		}
+		switch {
+		case parts[0] == "HI:":
+			perCPU := parts[1:]
+			softirqs.Hi = make([]uint64, len(perCPU))
+			for i, count := range perCPU {
+				if softirqs.Hi[i], err = strconv.ParseUint(count, 10, 64); err != nil {
+					return Softirqs{}, fmt.Errorf("%s: couldn't parse %q (HI%d): %w", ErrFileParse, count, i, err)
+				}
+			}
+		case parts[0] == "TIMER:":
+			perCPU := parts[1:]
+			softirqs.Timer = make([]uint64, len(perCPU))
+			for i, count := range perCPU {
+				if softirqs.Timer[i], err = strconv.ParseUint(count, 10, 64); err != nil {
+					return Softirqs{}, fmt.Errorf("%s: couldn't parse %q (TIMER%d): %w", ErrFileParse, count, i, err)
+				}
+			}
+		case parts[0] == "NET_TX:":
+			perCPU := parts[1:]
+			softirqs.NetTx = make([]uint64, len(perCPU))
+			for i, count := range perCPU {
+				if softirqs.NetTx[i], err = strconv.ParseUint(count, 10, 64); err != nil {
+					return Softirqs{}, fmt.Errorf("%s: couldn't parse %q (NET_TX%d): %w", ErrFileParse, count, i, err)
+				}
+			}
+		case parts[0] == "NET_RX:":
+			perCPU := parts[1:]
+			softirqs.NetRx = make([]uint64, len(perCPU))
+			for i, count := range perCPU {
+				if softirqs.NetRx[i], err = strconv.ParseUint(count, 10, 64); err != nil {
+					return Softirqs{}, fmt.Errorf("%s: couldn't parse %q (NET_RX%d): %w", ErrFileParse, count, i, err)
+				}
+			}
+		case parts[0] == "BLOCK:":
+			perCPU := parts[1:]
+			softirqs.Block = make([]uint64, len(perCPU))
+			for i, count := range perCPU {
+				if softirqs.Block[i], err = strconv.ParseUint(count, 10, 64); err != nil {
+					return Softirqs{}, fmt.Errorf("%s: couldn't parse %q (BLOCK%d): %w", ErrFileParse, count, i, err)
+				}
+			}
+		case parts[0] == "IRQ_POLL:":
+			perCPU := parts[1:]
+			softirqs.IRQPoll = make([]uint64, len(perCPU))
+			for i, count := range perCPU {
+				if softirqs.IRQPoll[i], err = strconv.ParseUint(count, 10, 64); err != nil {
+					return Softirqs{}, fmt.Errorf("%s: couldn't parse %q (IRQ_POLL%d): %w", ErrFileParse, count, i, err)
+				}
+			}
+		case parts[0] == "TASKLET:":
+			perCPU := parts[1:]
+			softirqs.Tasklet = make([]uint64, len(perCPU))
+			for i, count := range perCPU {
+				if softirqs.Tasklet[i], err = strconv.ParseUint(count, 10, 64); err != nil {
+					return Softirqs{}, fmt.Errorf("%s: couldn't parse %q (TASKLET%d): %w", ErrFileParse, count, i, err)
+				}
+			}
+		case parts[0] == "SCHED:":
+			perCPU := parts[1:]
+			softirqs.Sched = make([]uint64, len(perCPU))
+			for i, count := range perCPU {
+				if softirqs.Sched[i], err = strconv.ParseUint(count, 10, 64); err != nil {
+					return Softirqs{}, fmt.Errorf("%s: couldn't parse %q (SCHED%d): %w", ErrFileParse, count, i, err)
+				}
+			}
+		case parts[0] == "HRTIMER:":
+			perCPU := parts[1:]
+			softirqs.HRTimer = make([]uint64, len(perCPU))
+			for i, count := range perCPU {
+				if softirqs.HRTimer[i], err = strconv.ParseUint(count, 10, 64); err != nil {
+					return Softirqs{}, fmt.Errorf("%s: couldn't parse %q (HRTIMER%d): %w", ErrFileParse, count, i, err)
+				}
+			}
+		case parts[0] == "RCU:":
+			perCPU := parts[1:]
+			softirqs.RCU = make([]uint64, len(perCPU))
+			for i, count := range perCPU {
+				if softirqs.RCU[i], err = strconv.ParseUint(count, 10, 64); err != nil {
+					return Softirqs{}, fmt.Errorf("%s: couldn't parse %q (RCU%d): %w", ErrFileParse, count, i, err)
+				}
+			}
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return Softirqs{}, fmt.Errorf("%s: couldn't parse softirqs: %w", ErrFileParse, err)
+	}
+
+	return softirqs, scanner.Err()
+}