Hi!
As mentioned in [1], loadable Zabbix agent modules (DSOs) can be used
to extend the agent with all available PCP metrics (way over 1000 by
default).
https://www.zabbix.com/documentation/3.0/manual/config/items/loadablemodules
The implementation below provides the connection between the two APIs.
Otherwise it should be rather straightforward but a couple of remarks:
- pmNewContext(PM_CONTEXT_LOCAL, "") of course works as expected from
standalone clients but seems to fail from the DSO. This means that the
DSO to work PMCD must be running (which is the norm with PCP anyway).
If this is unfixable, then the code snippet could be removed.
- if you test this and it doesn't seem to work, check SELinux AVCs
- while the realloc-per-metric might seem a bit excessive it's done
only during initialization and Zabbix actually does the same as well
(and then some more)
What do you think, could this live in pcp.git?
An easy way to test this is to install just the Zabbix agent (e.g. from
[2]) and then do something like "zabbix_agentd -p | grep pcp".
1) http://oss.sgi.com/pipermail/pcp/2015-October/008550.html
2) http://repo.zabbix.com/zabbix/
/*
* Zabbix loadable PCP module
*
* Copyright (C) 2015 Marko Myllynen <myllynen@xxxxxxxxxx>
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* For description on Zabbix loadable modules, see:
* https://www.zabbix.com/documentation/3.0/manual/config/items/loadablemodules
*/
/*
* gcc -shared -fPIC -I/usr/src/zabbix/include -lpcp -o zbxpcp.so zbxpcp.c
*/
/*
* TODO
* - derived metrics support
* - config file support
* - conn type
* - conn target
* - replace defines
* - list of supported metrics
* - scaling
*/
#ifndef ZBX_PCP_METRIC_BASE
#define ZBX_PCP_METRIC_BASE ""
#endif
#ifndef ZBX_PCP_METRIC_PREFIX
#define ZBX_PCP_METRIC_PREFIX "pcp."
#endif
#include <stdlib.h>
#include <string.h>
/* PCP includes. */
#include <pcp/pmapi.h>
/* Zabbix includes. */
#include "sysinc.h"
#include "module.h"
/*
* PCP connection
*/
static int ctx = -1;
int zbx_module_pcp_init()
{
#ifndef ZBX_PCP_LOCAL_CONTEXT
ctx = pmNewContext(PM_CONTEXT_HOST, "local:");
#endif
if (ctx < 0) {
ctx = pmNewContext(PM_CONTEXT_LOCAL, "");
}
return ctx;
}
int zbx_module_pcp_uninit()
{
return pmDestroyContext(ctx);
}
/*
* Zabbix connection
*/
int zbx_module_init()
{
if (zbx_module_pcp_init() < 0)
return ZBX_MODULE_FAIL;
return ZBX_MODULE_OK;
}
int zbx_module_api_version()
{
return ZBX_MODULE_API_VERSION_ONE;
}
static int metric_count = 0;
static ZBX_METRIC *metrics = NULL;
void zbx_module_pcp_add_metric(const char *name);
ZBX_METRIC *zbx_module_item_list()
{
int sts;
ZBX_METRIC *mptr;
static ZBX_METRIC empty[] = { {NULL} };
/* Add PCP metrics to the Zabbix metric set. */
sts = pmTraversePMNS(ZBX_PCP_METRIC_BASE, zbx_module_pcp_add_metric);
if (sts < 0 || !metric_count) { free(metrics); return empty; }
/* Finalize the Zabbix set. */
mptr = metrics;
metrics = (ZBX_METRIC *)realloc(mptr, (metric_count + 1) *
sizeof(ZBX_METRIC));
if (metrics == NULL) { free(mptr); return empty; }
metrics[metric_count].key = NULL;
return metrics;
}
void zbx_module_item_timeout(int timeout)
{
/* PCP will handle timeouts. */
(void)timeout;
}
int zbx_module_uninit()
{
if (zbx_module_pcp_uninit() != 0)
return ZBX_MODULE_FAIL;
return ZBX_MODULE_OK;
}
/*
* Zabbix/PCP connection
*/
int zbx_module_pcp_fetch_metric(AGENT_REQUEST *request, AGENT_RESULT *result);
void zbx_module_pcp_add_metric(const char *name)
{
int sts;
pmID pmid[1];
pmDesc desc[1];
char *metric;
unsigned flags = 0;
char *param = NULL;
int *instlist;
char **namelist;
ZBX_METRIC *mptr = metrics;
/* PCP preparations. */
sts = pmLookupName(1, (char **)&name, pmid);
if (sts < 0) return;
sts = pmLookupDesc(pmid[0], desc);
if (sts < 0) return;
/* Construct the Zabbix metric name. */
metric = (char *)malloc(strlen(ZBX_PCP_METRIC_PREFIX) + strlen(name) + 1);
if (metric == NULL) return;
strcpy(metric, ZBX_PCP_METRIC_PREFIX);
strcat(metric, name);
/* Pick a PCP metric instance for use with zabbix_agentd -p. */
if (desc[0].indom != PM_INDOM_NULL) {
sts = pmGetInDom(desc[0].indom, &instlist, &namelist);
if (sts < 0) { free(metric); return; }
if (sts) {
flags = CF_HAVEPARAMS;
param = strdup(namelist[0]);
free(instlist);
free(namelist);
}
}
/* Ready for Zabbix. */
metrics = (ZBX_METRIC *)realloc(mptr, (metric_count + 1) *
sizeof(ZBX_METRIC));
if (metrics == NULL) { metrics = mptr; free(metric); free(param); return; }
metrics[metric_count].key = metric;
metrics[metric_count].flags = flags;
metrics[metric_count].function = zbx_module_pcp_fetch_metric;
metrics[metric_count].test_param = param;
metric_count++;
}
int zbx_module_pcp_fetch_metric(AGENT_REQUEST *request, AGENT_RESULT *result)
{
int sts;
char *metric[] = { request->key + strlen(ZBX_PCP_METRIC_PREFIX) };
char *inst;
pmID pmid[1];
pmDesc desc[1];
pmResult *rp;
pmAtomValue atom;
int iid = 0;
int i;
/* Parameter is the instance. */
switch(request->nparam) {
case 0:
inst = NULL;
break;
case 1:
inst = get_rparam(request, 0);
break;
default:
SET_MSG_RESULT(result, strdup("Extraneous instance
specification."));
return SYSINFO_RET_FAIL;
break;
}
/* Preparations and sanity checks. */
sts = pmLookupName(1, metric, pmid);
if (sts < 0) return SYSINFO_RET_FAIL;
sts = pmLookupDesc(pmid[0], desc);
if (sts < 0) return SYSINFO_RET_FAIL;
if (inst != NULL && desc[0].indom == PM_INDOM_NULL) {
SET_MSG_RESULT(result, strdup("Extraneous instance specification."));
return SYSINFO_RET_FAIL;
}
if ((inst == NULL && desc[0].indom != PM_INDOM_NULL) ||
(request->nparam == 1 && !strlen(inst))) {
SET_MSG_RESULT(result, strdup("Missing instance specification."));
return SYSINFO_RET_FAIL;
}
if (desc[0].indom != PM_INDOM_NULL) {
iid = pmLookupInDom(desc[0].indom, inst);
if (iid < 0) {
SET_MSG_RESULT(result, strdup("Instance not available."));
return SYSINFO_RET_FAIL;
}
}
/* Fetch the metric values. */
sts = pmFetch(1, pmid, &rp);
if (sts < 0) return SYSINFO_RET_FAIL;
if (rp->vset[0]->numval < 1) {
pmFreeResult(rp);
SET_MSG_RESULT(result, strdup("No value available."));
return SYSINFO_RET_FAIL;
}
/* Locate the correct instance. */
for (i = 0; desc[0].indom != PM_INDOM_NULL && i < rp->vset[0]->numval; i++)
{
if (rp->vset[0]->vlist[i].inst == iid) {
break;
}
}
if (i == rp->vset[0]->numval) {
pmFreeResult(rp);
return SYSINFO_RET_FAIL;
}
/* Extract the wanted value. */
sts = pmExtractValue(rp->vset[0]->valfmt, &rp->vset[0]->vlist[i],
desc[0].type, &atom, desc[0].type);
pmFreeResult(rp);
if (sts < 0) return SYSINFO_RET_FAIL;
/* Hand it to the caller. */
switch(desc[0].type) {
case PM_TYPE_32:
SET_UI64_RESULT(result, atom.l);
break;
case PM_TYPE_U32:
SET_UI64_RESULT(result, atom.ul);
break;
case PM_TYPE_64:
SET_UI64_RESULT(result, atom.ll);
break;
case PM_TYPE_U64:
SET_UI64_RESULT(result, atom.ull);
break;
case PM_TYPE_FLOAT:
SET_DBL_RESULT(result, atom.f);
break;
case PM_TYPE_DOUBLE:
SET_DBL_RESULT(result, atom.d);
break;
case PM_TYPE_STRING:
SET_STR_RESULT(result, strdup(atom.cp));
break;
default:
SET_MSG_RESULT(result, strdup("Unsupported metric value type."));
return SYSINFO_RET_FAIL;
break;
}
/* Success. */
return SYSINFO_RET_OK;
}
Thanks,
--
Marko Myllynen
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