[tarantool-patches] [PATCH v7] Configurable syslog destination

[Olga Arkhangelskaia <krishtal.olja@gmail.com>]

From: Olga Arkhangelskaia <arkholga@tarantool.org>

Added server option to syslog configuration.
Server option is responsible for log destination. At the momemt
there is two ways of usage:server=unix:/path/to/socket or
server=ipv4:port. If port is not set default udp port 514 is used.
If logging to syslog is set, however there is no server options -
default location is used: Linux /dev/log and Mac /var/run/syslog.
---
https://github.com/tarantool/tarantool/issues/3487
https://github.com/tarantool/tarantool/tree/OKriw/gh-3487-syslog-conf-dest-1.10


v1:
https://www.freelists.org/post/tarantool-patches/PATCH-03-Syslog-destination

v2:
https://www.freelists.org/post/tarantool-patches/PATCH-v2-03-Syslog-destination

v3:
https://www.freelists.org/post/tarantool-patches/PATCH-v3-04-Syslog-destination

v4:
https://www.freelists.org/post/tarantool-patches/PATCH-v4-04-Syslog-destination

v5:
https://www.freelists.org/post/tarantool-patches/PATCH-v5-04-Syslog-destination

v6:
https://www.freelists.org/post/tarantool-patches/PATCH-Configurable-syslog-destination

Changes in v2:
- Changed tests. Use random port, no sever is started, used current dir
- Changed basic structs - now we have emum for syslog dst, reuse log->pathi

Changes in v3:
- moved test to box-tap
- used pcall in case of stopped/unconfigured syslogd
- added syslog check syslog configuration test 

Changes in v4:
- fixed memory leak
- changed variables name
- removed unnecessary libs in tests
- removed pcall
- fixed identation 

Changes in v5:
-changed variable names
-fixed indentation
-changed test unix socket, now it looks the same as remote test
-fixed spelling error

Changes in v6:
-squashed patches into one
-deleted default syslog config. test
-fixed indentation

Changes in v7:
- fixed test for centos/fedora26/27

 src/say.c                 | 104 +++++++++++++++++++++++++++++++++++++++++++---
 src/say.h                 |  15 ++++++-
 test/box-tap/cfg.test.lua |  77 +++++++++++++++++++++++++++++++++-
 3 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/src/say.c b/src/say.c
index 063e0295c..ed46f7449 100644
--- a/src/say.c
+++ b/src/say.c
@@ -36,6 +36,7 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
+#include <netdb.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -48,6 +49,7 @@
 pid_t log_pid = 0;
 int log_level = S_INFO;
 enum say_format log_format = SF_PLAIN;
+enum { SAY_SYSLOG_DEFAULT_PORT = 512 };
 
 /** List of logs to rotate */
 static RLIST_HEAD(log_rotate_list);
@@ -473,16 +475,86 @@ syslog_connect_unix(const char *path)
 	return fd;
 }
 
+/**
+ * Connect to remote syslogd using server:port.
+ * @param server_address address of remote host.
+ * @retval not 0 Socket descriptor.
+ * @retval    -1 Socket error.
+ */
+static int
+syslog_connect_remote(const char *server_address)
+{
+	struct addrinfo *inf, hints, *ptr;
+	char *remote;
+	char buf[10];
+	char *portnum, *copy;
+	int fd = -1;
+	int ret;
+
+	copy = strdup(server_address);
+	if (copy == NULL) {
+		diag_set(OutOfMemory, strlen(server_address), "malloc",
+			 "stslog server address");
+		return fd;
+	}
+	portnum = copy;
+	remote = strsep(&portnum, ":");
+	if (portnum == NULL) {
+		snprintf(buf, sizeof(buf), "%d", SAY_SYSLOG_DEFAULT_PORT);
+		portnum = buf;
+	}
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_INET;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_protocol = IPPROTO_UDP;
+
+	ret = getaddrinfo(remote, portnum, &hints, &inf);
+	if (ret < 0) {
+		errno = EIO;
+		diag_set(SystemError, "getaddrinfo: %s",
+			 gai_strerror(ret));
+		goto out;
+	}
+	for (ptr = inf; ptr; ptr = ptr->ai_next) {
+		fd = socket(ptr->ai_family, ptr->ai_socktype, ptr->ai_protocol);
+		if (fd < 0) {
+			diag_set(SystemError, "socket");
+			continue;
+		}
+		if (connect(fd, inf->ai_addr, inf->ai_addrlen) != 0) {
+			close(fd);
+			fd = -1;
+			diag_set(SystemError, "connect");
+			continue;
+		}
+		break;
+	}
+	freeaddrinfo(inf);
+out:
+	free(copy);
+	return fd;
+}
+
 static inline int
 log_syslog_connect(struct log *log)
 {
 	/*
-	 * Try two locations: '/dev/log' for Linux and
+	 * If server option is not set use '/dev/log' for Linux and
 	 * '/var/run/syslog' for Mac.
 	 */
-	log->fd = syslog_connect_unix("/dev/log");
-	if (log->fd < 0)
-		log->fd = syslog_connect_unix("/var/run/syslog");
+	switch (log->syslog_server_type) {
+	case SAY_SYSLOG_UNIX:
+		log->fd = syslog_connect_unix(log->path);
+		break;
+	case SAY_SYSLOG_REMOTE:
+		log->fd = syslog_connect_remote(log->path);
+		break;
+	default:
+		log->fd = syslog_connect_unix("/dev/log");
+		if (log->fd < 0)
+			log->fd = syslog_connect_unix("/var/run/syslog");
+
+	}
 	return log->fd;
 }
 
@@ -498,6 +570,15 @@ log_syslog_init(struct log *log, const char *init_str)
 	if (say_parse_syslog_opts(init_str, &opts) < 0)
 		return -1;
 
+	log->syslog_server_type = opts.server_type;
+	if (log->syslog_server_type != SAY_SYSLOG_DEFAULT) {
+		log->path = strdup(opts.server_path);
+		if (log->path == NULL) {
+			diag_set(OutOfMemory, strlen(opts.server_path),
+				 "malloc", "server address");
+			return -1;
+		}
+	}
 	if (opts.identity == NULL)
 		log->syslog_ident = strdup("tarantool");
 	else
@@ -1047,6 +1128,8 @@ say_syslog_facility_by_name(const char *facility)
 int
 say_parse_syslog_opts(const char *init_str, struct say_syslog_opts *opts)
 {
+	opts->server_path = NULL;
+	opts->server_type = SAY_SYSLOG_DEFAULT;
 	opts->identity = NULL;
 	opts->facility = syslog_facility_MAX;
 	opts->copy = strdup(init_str);
@@ -1063,7 +1146,18 @@ say_parse_syslog_opts(const char *init_str, struct say_syslog_opts *opts)
 			break;
 
 		value = option;
-		if (say_parse_prefix(&value, "identity=")) {
+		if (say_parse_prefix(&value, "server=")) {
+			if (opts->server_path != NULL ||
+			    opts->server_type != SAY_SYSLOG_DEFAULT)
+				goto duplicate;
+			if (say_parse_prefix(&value, "unix:")) {
+				opts->server_type = SAY_SYSLOG_UNIX;
+				opts->server_path = value;
+			} else {
+				opts->server_type = SAY_SYSLOG_REMOTE;
+				opts->server_path = value;
+			}
+		} else if (say_parse_prefix(&value, "identity=")) {
 			if (opts->identity != NULL)
 				goto duplicate;
 			opts->identity = value;
diff --git a/src/say.h b/src/say.h
index 708637c41..bf6aa1896 100644
--- a/src/say.h
+++ b/src/say.h
@@ -79,6 +79,12 @@ say_log_level_is_enabled(int level)
 
 extern enum say_format log_format;
 
+enum say_syslog_server_type {
+	SAY_SYSLOG_DEFAULT,
+	SAY_SYSLOG_UNIX,
+	SAY_SYSLOG_REMOTE
+};
+
 enum say_logger_type {
 	/**
 	 * Before the app server core is initialized, we do not
@@ -141,7 +147,12 @@ struct log {
 	/** The current log level. */
 	int level;
 	enum say_logger_type type;
-	/** path to file if logging to file. */
+	/* Type of syslog destination. */
+	enum say_syslog_server_type syslog_server_type;
+	/** 
+	 * Path to file if logging to file, socket
+	 * or server address in case of syslog.
+	 */
 	char *path;
 	bool nonblock;
 	log_format_func_t format_func;
@@ -392,6 +403,8 @@ say_parse_logger_type(const char **str, enum say_logger_type *type);
 
 /** Syslog logger initialization params */
 struct say_syslog_opts {
+	enum say_syslog_server_type server_type;
+	const char *server_path;
 	const char *identity;
 	enum syslog_facility facility;
 	/* Input copy (content unspecified). */
diff --git a/test/box-tap/cfg.test.lua b/test/box-tap/cfg.test.lua
index 53e3c629a..cb61607fe 100755
--- a/test/box-tap/cfg.test.lua
+++ b/test/box-tap/cfg.test.lua
@@ -6,7 +6,7 @@ local socket = require('socket')
 local fio = require('fio')
 local uuid = require('uuid')
 local msgpack = require('msgpack')
-test:plan(93)
+test:plan(95)
 
 --------------------------------------------------------------------------------
 -- Invalid values
@@ -455,5 +455,80 @@ code = string.format(code_fmt, dir, instance_uuid, uuid.new())
 test:is(run_script(code), PANIC, "replicaset_uuid mismatch")
 fio.rmdir(dir)
 
+--
+-- Check syslog unix socket configuration
+--
+code = [[
+local socket = require('socket')
+local log = require('log')
+local fio = require('fio')
+
+path = fio.pathjoin(fio.cwd(), 'log_unix_socket_test.sock')
+unix_socket = socket('AF_UNIX', 'SOCK_DGRAM', 0)
+unix_socket:bind('unix/', path)
+
+opt = string.format("syslog:server=unix:%s,identity=tarantool", path)
+local res = 1
+local buf = 'Started\n'
+box.cfg{log = opt}
+
+-- make sure that socket would not block
+while unix_socket:readable(1) do
+    buf = buf .. unix_socket:recv(1000)
+end
+log.info("Test socket syslog destination")
+while unix_socket:readable(1) do
+    buf = buf .. unix_socket:recv(1000)
+    if buf:match('Test socket syslog destination') then res = 0 end
+end
+
+unix_socket:close()                                                         
+os.remove(path) 
+os.exit(res)
+]]
+test:is(run_script(code), 0, "unix socket syslog log configuration")
+
+--
+-- Check syslog remote configuration
+--
+code = [[
+local socket = require('socket')
+local log = require('log')
+
+addr = '127.0.0.1'
+port = 1000 + math.random(32768)
+
+sc = socket('AF_INET', 'SOCK_DGRAM', 'udp')
+local attempt = 0
+while attempt < 10 do
+    if not sc:bind (addr, port) then
+        port = 1000 + math.random(32768)
+        attempt = attempt + 1
+    else
+        break
+    end
+end
+sc:bind(addr, port)
+
+local opt = string.format("syslog:server=%s:%u,identity=tarantool", addr, port)
+local res = 1
+local buf = 'Started\n'
+box.cfg{log = opt}
+
+-- make sure that socket would not block
+while sc:readable(1) do
+    buf = buf .. sc:recv(1000)
+end
+log.info('Test syslog destination')
+while sc:readable(1) do
+    buf = buf .. sc:recv(1000)
+    if buf:match('Test syslog destination') then res = 0 end
+end
+
+sc:close()
+os.exit(res)
+]]
+test:is(run_script(code), 0, "remote syslog log configuration")
+
 test:check()
 os.exit(0)
-- 
2.14.3 (Apple Git-98)