From 0da0a8f9dae35e6a9cb63b9e4a3285e24c001af3 Mon Sep 17 00:00:00 2001
From: Nalin Dahyabhai <nalin@redhat.com>
Date: Thu, 14 Apr 2016 15:21:42 -0400
Subject: [PATCH] Add support for reading journal extras and in UTC

When told to read additional attributes from logs that we've sent to the
journal, pull out all of the non-trusted, non-user fields that we didn't
hard-code ourselves.  More of PR#20726 and PR#21889.

When reading entries in the journald log reader, set the time zone on
timestamps that we read to UTC, so that we send UTC values to the client
instead of values that are local to whatever timezone dockerd happens to
be running in.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com> (github: nalind)
---
 daemon/logger/journald/read.go | 67 +++++++++++++++++++++++++++++++++-
 1 file changed, 65 insertions(+), 2 deletions(-)

diff --git a/daemon/logger/journald/read.go b/daemon/logger/journald/read.go
index 3892eac356..bc009f61cf 100644
--- a/daemon/logger/journald/read.go
+++ b/daemon/logger/journald/read.go
@@ -50,6 +50,53 @@ package journald
 //	}
 //	return rc;
 //}
+//static int is_attribute_field(const char *msg, size_t length)
+//{
+//	const struct known_field {
+//		const char *name;
+//		size_t length;
+//	} fields[] = {
+//		{"MESSAGE", sizeof("MESSAGE") - 1},
+//		{"MESSAGE_ID", sizeof("MESSAGE_ID") - 1},
+//		{"PRIORITY", sizeof("PRIORITY") - 1},
+//		{"CODE_FILE", sizeof("CODE_FILE") - 1},
+//		{"CODE_LINE", sizeof("CODE_LINE") - 1},
+//		{"CODE_FUNC", sizeof("CODE_FUNC") - 1},
+//		{"ERRNO", sizeof("ERRNO") - 1},
+//		{"SYSLOG_FACILITY", sizeof("SYSLOG_FACILITY") - 1},
+//		{"SYSLOG_IDENTIFIER", sizeof("SYSLOG_IDENTIFIER") - 1},
+//		{"SYSLOG_PID", sizeof("SYSLOG_PID") - 1},
+//		{"CONTAINER_NAME", sizeof("CONTAINER_NAME") - 1},
+//		{"CONTAINER_ID", sizeof("CONTAINER_ID") - 1},
+//		{"CONTAINER_ID_FULL", sizeof("CONTAINER_ID_FULL") - 1},
+//		{"CONTAINER_TAG", sizeof("CONTAINER_TAG") - 1},
+//	};
+//	unsigned int i;
+//	void *p;
+//	if ((length < 1) || (msg[0] == '_') || ((p = memchr(msg, '=', length)) == NULL)) {
+//		return -1;
+//	}
+//	length = ((const char *) p) - msg;
+//	for (i = 0; i < sizeof(fields) / sizeof(fields[0]); i++) {
+//		if ((fields[i].length == length) && (memcmp(fields[i].name, msg, length) == 0)) {
+//			return -1;
+//		}
+//	}
+//	return 0;
+//}
+//static int get_attribute_field(sd_journal *j, const char **msg, size_t *length)
+//{
+//	int rc;
+//	*msg = NULL;
+//	*length = 0;
+//	while ((rc = sd_journal_enumerate_data(j, (const void **) msg, length)) > 0) {
+//		if (is_attribute_field(*msg, *length) == 0) {
+//			break;
+//		}
+//		rc = -ENOENT;
+//	}
+//	return rc;
+//}
 //static int wait_for_data_or_close(sd_journal *j, int pipefd)
 //{
 //	struct pollfd fds[2];
@@ -98,6 +145,7 @@ import "C"
 
 import (
 	"fmt"
+	"strings"
 	"time"
 	"unsafe"
 
@@ -116,7 +164,7 @@ func (s *journald) Close() error {
 }
 
 func (s *journald) drainJournal(logWatcher *logger.LogWatcher, config logger.ReadConfig, j *C.sd_journal, oldCursor string) string {
-	var msg, cursor *C.char
+	var msg, data, cursor *C.char
 	var length C.size_t
 	var stamp C.uint64_t
 	var priority C.int
@@ -156,8 +204,23 @@ drain:
 			} else if priority == C.int(journal.PriInfo) {
 				source = "stdout"
 			}
+			// Retrieve the values of any variables we're adding to the journal.
+			attrs := make(map[string]string)
+			C.sd_journal_restart_data(j)
+			for C.get_attribute_field(j, &data, &length) > C.int(0) {
+				kv := strings.SplitN(C.GoStringN(data, C.int(length)), "=", 2)
+				attrs[kv[0]] = kv[1]
+			}
+			if len(attrs) == 0 {
+				attrs = nil
+			}
 			// Send the log message.
-			logWatcher.Msg <- &logger.Message{Line: line, Source: source, Timestamp: timestamp}
+			logWatcher.Msg <- &logger.Message{
+				Line:      line,
+				Source:    source,
+				Timestamp: timestamp.In(time.UTC),
+				Attrs:     attrs,
+			}
 		}
 		// If we're at the end of the journal, we're done (for now).
 		if C.sd_journal_next(j) <= 0 {