[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, 51 insertions, 0 deletions

diff --git a/vendor/github.com/prometheus/procfs/proc_sys.go b/vendor/github.com/prometheus/procfs/proc_sys.go
new file mode 100644
index 000000000..12c5bf05b
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/proc_sys.go
@@ -0,0 +1,51 @@
+// 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 (
+	"fmt"
+	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+func sysctlToPath(sysctl string) string {
+	return strings.Replace(sysctl, ".", "/", -1)
+}
+
+func (fs FS) SysctlStrings(sysctl string) ([]string, error) {
+	value, err := util.SysReadFile(fs.proc.Path("sys", sysctlToPath(sysctl)))
+	if err != nil {
+		return nil, err
+	}
+	return strings.Fields(value), nil
+
+}
+
+func (fs FS) SysctlInts(sysctl string) ([]int, error) {
+	fields, err := fs.SysctlStrings(sysctl)
+	if err != nil {
+		return nil, err
+	}
+
+	values := make([]int, len(fields))
+	for i, f := range fields {
+		vp := util.NewValueParser(f)
+		values[i] = vp.Int()
+		if err := vp.Err(); err != nil {
+			return nil, fmt.Errorf("%s: field %d in sysctl %s is not a valid int: %w", ErrFileParse, i, sysctl, err)
+		}
+	}
+	return values, nil
+}