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This commit is contained in:
Florian Obser 2018-05-07 14:54:39 +02:00
commit 52919f767c
3 changed files with 487 additions and 0 deletions

21
Makefile Normal file
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BINDIR= /var/www/metrics
PROG= kmunin_exporter
SRCS= kmunin_exporter.c
LDSTATIC= ${STATIC}
NOMAN= YES
#DEBUG= -g -DDEBUG=3 -O0
CFLAGS+= -Wall
CFLAGS+= -Wstrict-prototypes -Wmissing-prototypes
CFLAGS+= -Wmissing-declarations
CFLAGS+= -Wshadow -Wpointer-arith -Wcast-qual
CFLAGS+= -Wsign-compare
CFLAGS+= -I/usr/local/include
LDADD+= -L/usr/local/lib -lkcgihtml -lkcgi -lz
LDADD+= -levent
DPADD+= ${LIBEVENT}
.include <bsd.prog.mk>

8
httpd.conf Normal file
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# example httpd.conf snipped
server "kmuninexporter" {
listen on localhost port 4848
location "/metrics/*" {
fastcgi
root "/"
}
}

458
kmunin_exporter.c Normal file
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/*
* Copyright (c) 2018 Florian Obser <florian@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <err.h>
#include <errno.h>
#include <event.h>
#include <netdb.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <kcgi.h>
#define WAIT_CONNECT 1
#define WAIT_CONNECT_SUCCEED 2
#define WAIT_BANNER 3
#define WRITE_LIST 4
#define WAIT_LIST 5
#define FETCH_ELEMENT 6
#define WAIT_FETCHED_DATA 7
#define BANNER_PREFIX "# munin node at "
struct munin {
SLIST_ENTRY(munin) entry;
struct event ev;
struct kreq *r;
struct sockaddr_storage ss;
int s;
int state;
char hbuf[NI_MAXHOST];
char *data;
ssize_t write_size;
char *hostname;
char *list;
char *current_metric;
};
SLIST_HEAD(munin_head, munin);
struct munin_head munins;
void write_handler(int, short, void *);
void read_handler(int, short, void *);
void export(struct munin *);
void khttp_log(struct kreq *, char *, ...);
void
khttp_log(struct kreq *r, char *fmt, ...)
{
va_list ap;
int ret;
char *str;
va_start(ap, fmt);
ret = vasprintf(&str, fmt, ap);
va_end(ap);
if (ret >= 0) {
khttp_puts(r, "# ");
khttp_puts(r, str);
khttp_putc(r, '\n');
}
free(str);
}
void
export(struct munin *munin)
{
char *d, *line, *k, *v, *str;
d = munin->data;
while((line = strsep(&d, "\n")) != NULL) {
if (*line == '\0')
continue; /* two adjacent delimiters */
if (*line == '#') {
asprintf(&str, "# skipping %s metric comment: %s\n",
munin->current_metric, line);
khttp_puts(munin->r, str);
free(str);
continue;
}
if (line[0] == '.' && line[1] == '\0')
break; /* munin EOF marker */
if ((v = strchr(line, ' ')) == NULL) {
asprintf(&str, "# skipping malformed line: %s\n", line);
khttp_puts(munin->r, str);
free(str);
continue;
} else
*v++ = '\0';
if ((k = strstr(line, ".value")) != NULL)
*k = '\0';
k = line;
asprintf(&str,
"# TYPE %s_%s counter\n%s_%s{hostname=\"%s\"} %s\n",
munin->current_metric, k,
munin->current_metric, k,
munin->hostname, v);
khttp_puts(munin->r, str);
free(str);
}
}
void
read_handler(int fd, short events, void *arg)
{
struct munin *munin, *i, *t;
ssize_t n;
char buf[4096], *tmp, *str;
munin = (struct munin*)arg;
n = read(fd, buf, sizeof(buf) - 1);
switch (n) {
case -1:
switch (errno) {
case EINTR:
case EAGAIN:
return;
default:
asprintf(&str, "# read: %s\n", strerror(errno));
khttp_puts(munin->r, str);
free(str);
goto fail;
}
break;
case 0:
asprintf(&str, "# read: closed connection\n");
khttp_puts(munin->r, str);
free(str);
goto fail;
default:
break;
}
buf[n] = '\0';
if (munin->data == NULL)
munin->data = strdup(buf);
else {
tmp = munin->data;
asprintf(&munin->data, "%s%s", munin->data, buf);
free(tmp);
}
switch (munin->state) {
case WAIT_CONNECT_SUCCEED:
munin->state = WAIT_BANNER;
/* connection succeeded, canceling others */
SLIST_FOREACH_SAFE(i, &munins, entry, t) {
if (i != munin) {
event_del(&i->ev);
close(i->s);
SLIST_REMOVE(&munins, i, munin, entry);
free(i);
}
}
/* fall through */
case WAIT_BANNER:
if ((tmp = strchr(munin->data, '\n')) != NULL) {
*tmp = '\0';
if (strncmp(BANNER_PREFIX, munin->data,
sizeof(BANNER_PREFIX) - 1) == 0) {
munin->hostname = strdup(munin->data +
(sizeof(BANNER_PREFIX) - 1));
asprintf(&str, "#hostname: %s\n",
munin->hostname);
khttp_puts(munin->r, str);
free(str);
}
free(munin->data);
munin->data = strdup("list\n");
munin->write_size = sizeof("list\n") - 1;
munin->state = WRITE_LIST;
event_del(&munin->ev);
event_set(&munin->ev, munin->s, EV_WRITE | EV_PERSIST,
write_handler, munin);
event_add(&munin->ev, NULL);
}
break;
case WAIT_LIST:
/* XXX ignore comment lines */
if ((tmp = strchr(munin->data, '\n')) != NULL) {
*tmp = '\0';
munin->list = strdup(munin->data);
munin->state = FETCH_ELEMENT;
event_del(&munin->ev);
event_set(&munin->ev, munin->s, EV_WRITE | EV_PERSIST,
write_handler, munin);
event_add(&munin->ev, NULL);
}
break;
case WAIT_FETCHED_DATA:
if ((munin->data[0] == '.' && munin->data[1] == '\n')
|| strstr(munin->data, "\n.\n") != NULL) {
export(munin);
free(munin->data);
free(munin->current_metric);
munin->state = FETCH_ELEMENT;
event_del(&munin->ev);
event_set(&munin->ev, munin->s, EV_WRITE | EV_PERSIST,
write_handler, munin);
event_add(&munin->ev, NULL);
}
break;
default:
asprintf(&str, "# %s: unknown state: %d\n", __func__,
munin->state);
khttp_puts(munin->r, str);
free(str);
exit(1);
break;
}
return;
fail:
event_del(&munin->ev);
close(fd);
SLIST_REMOVE(&munins, munin, munin, entry);
free(munin);
}
void
write_handler(int fd, short events, void *arg)
{
struct munin *munin;
int error = 0;
socklen_t len = sizeof(error);
char *tmp, *str;
munin = (struct munin*)arg;
switch (munin->state) {
case WAIT_CONNECT:
if (getsockopt(munin->s, SOL_SOCKET, SO_ERROR, &error, &len)
< 0) {
asprintf(&str, "# getsockopt: %s\n", strerror(errno));
khttp_puts(munin->r, str);
free(str);
goto fail;
}
if (error != 0) {
errno = error;
asprintf(&str, "# connect: %s\n", strerror(errno));
khttp_puts(munin->r, str);
free(str);
goto fail;
}
event_del(&munin->ev);
munin->state = WAIT_CONNECT_SUCCEED;
event_set(&munin->ev, munin->s, EV_READ | EV_PERSIST,
read_handler, munin);
event_add(&munin->ev, NULL);
break;
case WRITE_LIST:
if (write(fd, munin->data, munin->write_size) !=
munin->write_size) {
asprintf(&str, "# write: %s\n", strerror(errno));
khttp_puts(munin->r, str);
free(str);
goto fail;
}
free(munin->data);
munin->data = NULL;
munin->write_size = -1;
event_del(&munin->ev);
munin->state = WAIT_LIST;
event_set(&munin->ev, munin->s, EV_READ | EV_PERSIST,
read_handler, munin);
event_add(&munin->ev, NULL);
break;
case FETCH_ELEMENT:
tmp = strsep(&munin->list, " \t");
if (tmp == NULL) {
free(munin->list);
goto fail; // XXX this is success, we are done!
} else if (tmp == '\0')
break; /* two adjacent delimiters */
munin->current_metric = strdup(tmp);
munin->write_size = asprintf(&munin->data, "fetch %s\n",
munin->current_metric);
if (write(fd, munin->data, munin->write_size) !=
munin->write_size) {
asprintf(&str, "# write: %s\n", strerror(errno));
khttp_puts(munin->r, str);
free(str);
goto fail;
}
free(munin->data);
munin->data = NULL;
munin->write_size = -1;
event_del(&munin->ev);
munin->state = WAIT_FETCHED_DATA;
event_set(&munin->ev, munin->s, EV_READ | EV_PERSIST,
read_handler, munin);
event_add(&munin->ev, NULL);
break;
default:
asprintf(&str, "# %s: unknown state: %d\n", __func__,
munin->state);
khttp_puts(munin->r, str);
free(str);
exit(1);
break;
}
return;
fail:
event_del(&munin->ev);
close(fd);
SLIST_REMOVE(&munins, munin, munin, entry);
free(munin);
}
int
main(int argc, char **argv)
{
struct kreq r;
struct addrinfo hints, *res, *res0;
struct munin *munin;
int error;
char *host = NULL;
if (pledge("stdio dns inet proc", "") == -1)
err(1, "pledge");
if (KCGI_OK != khttp_parse(&r, NULL, 0, NULL, 0, 0))
return(EXIT_FAILURE);
if (pledge("stdio dns inet", "") == -1)
err(1, "pledge");
if (r.fullpath != NULL) {
if (r.fullpath[0] == '/')
host = r.fullpath + 1;
else
host = r.fullpath;
} else {
khttp_head(&r, kresps[KRESP_STATUS], "%s", khttps[KHTTP_500]);
khttp_head(&r, kresps[KRESP_CONTENT_TYPE], "%s", "text/plain");
khttp_body(&r);
khttp_puts(&r, "# missing host\n");
khttp_free(&r);
return (EXIT_SUCCESS);
}
SLIST_INIT(&munins);
event_init();
khttp_head(&r, kresps[KRESP_STATUS], "%s", khttps[KHTTP_200]);
khttp_head(&r, kresps[KRESP_CONTENT_TYPE], "%s", "text/plain");
khttp_body(&r);
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
error = getaddrinfo(host, "4949", &hints, &res0);
if (error) {
khttp_log(&r, "getaddrinfo: %s", gai_strerror(error));
goto out;
}
for (res = res0; res; res = res->ai_next) {
if ((munin = calloc(1, sizeof(*munin))) == NULL) {
khttp_log(&r, "malloc: %s", strerror(errno));
goto out;
}
error = getnameinfo(res->ai_addr, res->ai_addr->sa_len,
munin->hbuf, sizeof(munin->hbuf), NULL, 0, NI_NUMERICHOST |
NI_NUMERICSERV);
if (error) {
khttp_log(&r, "could not get numeric hostname: %s",
gai_strerror(error));
goto out;
}
memcpy(&munin->ss, res->ai_addr, res->ai_addrlen);
if ((munin->s = socket(res->ai_family, res->ai_socktype |
SOCK_NONBLOCK, res->ai_protocol)) == -1) {
khttp_log(&r, "socket: %s", strerror(errno));
goto out;
}
munin->r = &r;
munin->state = WAIT_CONNECT;
event_set(&munin->ev, munin->s, EV_WRITE | EV_PERSIST,
write_handler, munin);
event_add(&munin->ev, NULL);
SLIST_INSERT_HEAD(&munins, munin, entry);
}
freeaddrinfo(res0);
if (pledge("stdio inet", "") == -1)
err(1, "pledge");
SLIST_FOREACH(munin, &munins, entry) {
if (connect(munin->s, (struct sockaddr *)&munin->ss,
munin->ss.ss_len) == -1)
if (errno != EINPROGRESS) {
khttp_log(&r, "connect: %s", strerror(errno));
goto out;
}
}
if (pledge("stdio", "") == -1)
err(1, "pledge");
event_dispatch();
khttp_puts(&r, "# OK\n");
out:
khttp_free(&r);
return (EXIT_SUCCESS);
}