go.mod, vendor: update (#3358)

* go.mod, vendor: remove unnecessary dependencies

Commands:
1. go mod tidy
2. go mod vendor

* go.mod, vendor: update cloud.google.com/go

Commands:
1. go get -u cloud.google.com/go
2. go mod tidy
3. go mod vendor

* go.mod, vendor: update cloud.google.com/*

Commands:
1. go get -u cloud.google.com/storage cloud.google.com/logging
2. go mod tidy
3. go mod vendor

* go.mod, .golangci.yml, vendor: update *lint*

Commands:
1. go get -u golang.org/x/tools github.com/golangci/golangci-lint@v1.47.0
2. go mod tidy
3. go mod vendor
4. edit .golangci.yml to suppress new errors (resolved in the same PR later)

* all: fix lint errors

hash.go: copy() recommended by gosimple
parse.go: ent is never nil
verifier.go: signal.Notify() with unbuffered channel is bad. Have no idea why.

* .golangci.yml: adjust godot rules

check-all is deprecated, but still work
if you're hesitating too - I'll remove this commit

1 files changed, 48 insertions, 0 deletions

diff --git a/vendor/github.com/prometheus/procfs/internal/util/sysreadfile.go b/vendor/github.com/prometheus/procfs/internal/util/sysreadfile.go
new file mode 100644
index 000000000..c07de0b6c
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/internal/util/sysreadfile.go
@@ -0,0 +1,48 @@
+// 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.
+
+// +build linux,!appengine
+
+package util
+
+import (
+	"bytes"
+	"os"
+	"syscall"
+)
+
+// SysReadFile is a simplified ioutil.ReadFile that invokes syscall.Read directly.
+// https://github.com/prometheus/node_exporter/pull/728/files
+//
+// Note that this function will not read files larger than 128 bytes.
+func SysReadFile(file string) (string, error) {
+	f, err := os.Open(file)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	// On some machines, hwmon drivers are broken and return EAGAIN.  This causes
+	// Go's ioutil.ReadFile implementation to poll forever.
+	//
+	// Since we either want to read data or bail immediately, do the simplest
+	// possible read using syscall directly.
+	const sysFileBufferSize = 128
+	b := make([]byte, sysFileBufferSize)
+	n, err := syscall.Read(int(f.Fd()), b)
+	if err != nil {
+		return "", err
+	}
+
+	return string(bytes.TrimSpace(b[:n])), nil
+}