[VOL-2312] Logging - Integrate voltctl with new etcd-based dynamic loglevel mechanism. Testing is in progress
Change-Id: I2e13bb79008c9a49ebb6f58e575f51efebe6dbfd
diff --git a/vendor/github.com/coreos/go-systemd/journal/journal.go b/vendor/github.com/coreos/go-systemd/journal/journal.go
new file mode 100644
index 0000000..a0f4837
--- /dev/null
+++ b/vendor/github.com/coreos/go-systemd/journal/journal.go
@@ -0,0 +1,225 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// 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 journal provides write bindings to the local systemd journal.
+// It is implemented in pure Go and connects to the journal directly over its
+// unix socket.
+//
+// To read from the journal, see the "sdjournal" package, which wraps the
+// sd-journal a C API.
+//
+// http://www.freedesktop.org/software/systemd/man/systemd-journald.service.html
+package journal
+
+import (
+ "bytes"
+ "encoding/binary"
+ "errors"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "net"
+ "os"
+ "strconv"
+ "strings"
+ "sync"
+ "sync/atomic"
+ "syscall"
+ "unsafe"
+)
+
+// Priority of a journal message
+type Priority int
+
+const (
+ PriEmerg Priority = iota
+ PriAlert
+ PriCrit
+ PriErr
+ PriWarning
+ PriNotice
+ PriInfo
+ PriDebug
+)
+
+var (
+ // This can be overridden at build-time:
+ // https://github.com/golang/go/wiki/GcToolchainTricks#including-build-information-in-the-executable
+ journalSocket = "/run/systemd/journal/socket"
+
+ // unixConnPtr atomically holds the local unconnected Unix-domain socket.
+ // Concrete safe pointer type: *net.UnixConn
+ unixConnPtr unsafe.Pointer
+ // onceConn ensures that unixConnPtr is initialized exactly once.
+ onceConn sync.Once
+)
+
+func init() {
+ onceConn.Do(initConn)
+}
+
+// Enabled checks whether the local systemd journal is available for logging.
+func Enabled() bool {
+ onceConn.Do(initConn)
+
+ if (*net.UnixConn)(atomic.LoadPointer(&unixConnPtr)) == nil {
+ return false
+ }
+
+ if _, err := net.Dial("unixgram", journalSocket); err != nil {
+ return false
+ }
+
+ return true
+}
+
+// Send a message to the local systemd journal. vars is a map of journald
+// fields to values. Fields must be composed of uppercase letters, numbers,
+// and underscores, but must not start with an underscore. Within these
+// restrictions, any arbitrary field name may be used. Some names have special
+// significance: see the journalctl documentation
+// (http://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html)
+// for more details. vars may be nil.
+func Send(message string, priority Priority, vars map[string]string) error {
+ conn := (*net.UnixConn)(atomic.LoadPointer(&unixConnPtr))
+ if conn == nil {
+ return errors.New("could not initialize socket to journald")
+ }
+
+ socketAddr := &net.UnixAddr{
+ Name: journalSocket,
+ Net: "unixgram",
+ }
+
+ data := new(bytes.Buffer)
+ appendVariable(data, "PRIORITY", strconv.Itoa(int(priority)))
+ appendVariable(data, "MESSAGE", message)
+ for k, v := range vars {
+ appendVariable(data, k, v)
+ }
+
+ _, _, err := conn.WriteMsgUnix(data.Bytes(), nil, socketAddr)
+ if err == nil {
+ return nil
+ }
+ if !isSocketSpaceError(err) {
+ return err
+ }
+
+ // Large log entry, send it via tempfile and ancillary-fd.
+ file, err := tempFd()
+ if err != nil {
+ return err
+ }
+ defer file.Close()
+ _, err = io.Copy(file, data)
+ if err != nil {
+ return err
+ }
+ rights := syscall.UnixRights(int(file.Fd()))
+ _, _, err = conn.WriteMsgUnix([]byte{}, rights, socketAddr)
+ if err != nil {
+ return err
+ }
+
+ return nil
+}
+
+// Print prints a message to the local systemd journal using Send().
+func Print(priority Priority, format string, a ...interface{}) error {
+ return Send(fmt.Sprintf(format, a...), priority, nil)
+}
+
+func appendVariable(w io.Writer, name, value string) {
+ if err := validVarName(name); err != nil {
+ fmt.Fprintf(os.Stderr, "variable name %s contains invalid character, ignoring\n", name)
+ }
+ if strings.ContainsRune(value, '\n') {
+ /* When the value contains a newline, we write:
+ * - the variable name, followed by a newline
+ * - the size (in 64bit little endian format)
+ * - the data, followed by a newline
+ */
+ fmt.Fprintln(w, name)
+ binary.Write(w, binary.LittleEndian, uint64(len(value)))
+ fmt.Fprintln(w, value)
+ } else {
+ /* just write the variable and value all on one line */
+ fmt.Fprintf(w, "%s=%s\n", name, value)
+ }
+}
+
+// validVarName validates a variable name to make sure journald will accept it.
+// The variable name must be in uppercase and consist only of characters,
+// numbers and underscores, and may not begin with an underscore:
+// https://www.freedesktop.org/software/systemd/man/sd_journal_print.html
+func validVarName(name string) error {
+ if name == "" {
+ return errors.New("Empty variable name")
+ } else if name[0] == '_' {
+ return errors.New("Variable name begins with an underscore")
+ }
+
+ for _, c := range name {
+ if !(('A' <= c && c <= 'Z') || ('0' <= c && c <= '9') || c == '_') {
+ return errors.New("Variable name contains invalid characters")
+ }
+ }
+ return nil
+}
+
+// isSocketSpaceError checks whether the error is signaling
+// an "overlarge message" condition.
+func isSocketSpaceError(err error) bool {
+ opErr, ok := err.(*net.OpError)
+ if !ok || opErr == nil {
+ return false
+ }
+
+ sysErr, ok := opErr.Err.(*os.SyscallError)
+ if !ok || sysErr == nil {
+ return false
+ }
+
+ return sysErr.Err == syscall.EMSGSIZE || sysErr.Err == syscall.ENOBUFS
+}
+
+// tempFd creates a temporary, unlinked file under `/dev/shm`.
+func tempFd() (*os.File, error) {
+ file, err := ioutil.TempFile("/dev/shm/", "journal.XXXXX")
+ if err != nil {
+ return nil, err
+ }
+ err = syscall.Unlink(file.Name())
+ if err != nil {
+ return nil, err
+ }
+ return file, nil
+}
+
+// initConn initializes the global `unixConnPtr` socket.
+// It is meant to be called exactly once, at program startup.
+func initConn() {
+ autobind, err := net.ResolveUnixAddr("unixgram", "")
+ if err != nil {
+ return
+ }
+
+ sock, err := net.ListenUnixgram("unixgram", autobind)
+ if err != nil {
+ return
+ }
+
+ atomic.StorePointer(&unixConnPtr, unsafe.Pointer(sock))
+}