[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, 63 insertions, 0 deletions

diff --git a/vendor/github.com/prometheus/procfs/kernel_random.go b/vendor/github.com/prometheus/procfs/kernel_random.go
new file mode 100644
index 000000000..db88566bd
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/kernel_random.go
@@ -0,0 +1,63 @@
+// Copyright 2020 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.
+
+//go:build !windows
+// +build !windows
+
+package procfs
+
+import (
+	"os"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+// KernelRandom contains information about to the kernel's random number generator.
+type KernelRandom struct {
+	// EntropyAvaliable gives the available entropy, in bits.
+	EntropyAvaliable *uint64
+	// PoolSize gives the size of the entropy pool, in bits.
+	PoolSize *uint64
+	// URandomMinReseedSeconds is the number of seconds after which the DRNG will be reseeded.
+	URandomMinReseedSeconds *uint64
+	// WriteWakeupThreshold the number of bits of entropy below which we wake up processes
+	// that do a select(2) or poll(2) for write access to /dev/random.
+	WriteWakeupThreshold *uint64
+	// ReadWakeupThreshold is the number of bits of entropy required for waking up processes that sleep
+	// waiting for entropy from /dev/random.
+	ReadWakeupThreshold *uint64
+}
+
+// KernelRandom returns values from /proc/sys/kernel/random.
+func (fs FS) KernelRandom() (KernelRandom, error) {
+	random := KernelRandom{}
+
+	for file, p := range map[string]**uint64{
+		"entropy_avail":           &random.EntropyAvaliable,
+		"poolsize":                &random.PoolSize,
+		"urandom_min_reseed_secs": &random.URandomMinReseedSeconds,
+		"write_wakeup_threshold":  &random.WriteWakeupThreshold,
+		"read_wakeup_threshold":   &random.ReadWakeupThreshold,
+	} {
+		val, err := util.ReadUintFromFile(fs.proc.Path("sys", "kernel", "random", file))
+		if os.IsNotExist(err) {
+			continue
+		}
+		if err != nil {
+			return random, err
+		}
+		*p = &val
+	}
+
+	return random, nil
+}