MEDIUM: log: add support for logging to a ring buffer
Now by prefixing a log server with "ring@<name>" it's possible to send
the logs to a ring buffer. One nice thing is that it allows multiple
sessions to consult the logs in real time in parallel over the CLI, and
without requiring file system access. At the moment, ring0 is created as
a default sink for tracing purposes and is available. No option is
provided to create new rings though this is trivial to add to the global
section.
diff --git a/src/log.c b/src/log.c
index 1b34c63..b96c174 100644
--- a/src/log.c
+++ b/src/log.c
@@ -39,7 +39,9 @@
#include <proto/fd.h>
#include <proto/frontend.h>
#include <proto/log.h>
+#include <proto/ring.h>
#include <proto/sample.h>
+#include <proto/sink.h>
#include <proto/ssl_sock.h>
#include <proto/stream.h>
#include <proto/stream_interface.h>
@@ -1000,6 +1002,20 @@
/* now, back to the address */
logsrv->type = LOG_TARGET_DGRAM;
+ if (strncmp(args[1], "ring@", 5) == 0) {
+ struct sink *sink = sink_find(args[1] + 5);
+
+ if (!sink || sink->type != SINK_TYPE_BUFFER) {
+ memprintf(err, "cannot find ring buffer '%s'", args[1] + 5);
+ goto error;
+ }
+
+ logsrv->addr.ss_family = AF_UNSPEC;
+ logsrv->type = LOG_TARGET_BUFFER;
+ logsrv->ring = sink->ctx.ring;
+ goto done;
+ }
+
if (strncmp(args[1], "fd@", 3) == 0)
logsrv->type = LOG_TARGET_FD;
@@ -1017,6 +1033,7 @@
if (!port1)
set_host_port(&logsrv->addr, SYSLOG_PORT);
}
+ done:
LIST_ADDQ(logsrvs, &logsrv->list);
return 1;
@@ -1510,12 +1527,15 @@
/* the socket's address is a file descriptor */
plogfd = (int *)&((struct sockaddr_in *)&logsrv->addr)->sin_addr.s_addr;
}
+ else if (logsrv->type == LOG_TARGET_BUFFER) {
+ plogfd = NULL;
+ }
else if (logsrv->addr.ss_family == AF_UNIX)
plogfd = &logfdunix;
else
plogfd = &logfdinet;
- if (unlikely(*plogfd < 0)) {
+ if (plogfd && unlikely(*plogfd < 0)) {
/* socket not successfully initialized yet */
if ((*plogfd = socket(logsrv->addr.ss_family, SOCK_DGRAM,
(logsrv->addr.ss_family == AF_UNIX) ? 0 : IPPROTO_UDP)) < 0) {
@@ -1652,7 +1672,7 @@
max = MIN(size, maxlen - sd_max) - 1;
send:
if (logsrv->addr.ss_family == AF_UNSPEC) {
- /* the target is a direct file descriptor */
+ /* the target is a file descriptor or a ring buffer */
struct ist msg[7];
msg[0].ptr = hdr_ptr; msg[0].len = hdr_max;
@@ -1663,7 +1683,10 @@
msg[5].ptr = sd; msg[5].len = sd_max;
msg[6].ptr = dataptr; msg[6].len = max;
- sent = fd_write_frag_line(*plogfd, ~0, NULL, 0, msg, 7, 1);
+ if (logsrv->type == LOG_TARGET_BUFFER)
+ sent = ring_write(logsrv->ring, ~0, NULL, 0, msg, 7);
+ else /* LOG_TARGET_FD */
+ sent = fd_write_frag_line(*plogfd, ~0, NULL, 0, msg, 7, 1);
}
else {
iovec[0].iov_base = hdr_ptr;