Initial import of the first (working) draft

Makefile

@@ -0,0 +1,19 @@
+CC=cc
+CFLAGS=-Wall -Wextra
+TARGET=netbsd_exporter
+REMOTE_HOST=192.168.2.51
+REMOTE_USER=user
+REMOTE_DIR=/home/user/netbsd_exporter
+
+all: $(TARGET)
+
+$(TARGET): netbsd_exporter.c
+	$(CC) $(CFLAGS) -o $@ $<
+
+clean:
+	rm -f $(TARGET)
+
+deploy: $(TARGET)
+	scp $(TARGET) $(REMOTE_USER)@$(REMOTE_HOST):$(REMOTE_DIR)
+
+.PHONY: all clean deploy

netbsd_exporter.c

@@ -0,0 +1,203 @@
+/*-
+ * Copyright (c) 2023 Matthias Petermann <mp@petermann-it.de>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* This program retrieves system metrics such as disk I/O, network I/O,
+ * RAM and filesystem usage, as well as CPU load from the running system
+ * and exposes them in the format of Prometheus metrics. It is designed
+ * to be integrated into inetd, providing a lightweight, NetBSD-focused
+ * alternative to the node_exporter.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/statvfs.h>
+#include <sys/sysctl.h>
+#include <string.h>
+#include <ifaddrs.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#include <netinet/if_ether.h>
+#include <netinet/ip.h>
+#include <netinet/ip6.h>
+#include <sys/iostat.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <uvm/uvm_extern.h>
+
+/* sysctl hw.drivestats buffer. */
+static struct io_sysctl *drives = NULL;
+
+
+void print_filesystem_metric(const char* metric, const char* device, const char* mountpoint, long value) {
+    printf("os_filesystem_%s_bytes{device=\"%s\",mountpoint=\"%s\"} %ld\n", metric, device, mountpoint, value);
+}
+
+void print_disk_io_metric(const char* device, long long unsigned int rbytes, long long unsigned int wbytes) {
+    printf("os_disk_read_bytes{device=\"%s\"} %llu\n", device, rbytes);
+    printf("os_disk_write_bytes{device=\"%s\"} %llu\n", device, wbytes);
+}
+
+void print_load_metric(const char* metric, double value) {
+    printf("os_load%s %lf\n", metric, value);
+}
+
+void print_network_metric(const char* interface, unsigned long long rxbytes, unsigned long long txbytes, unsigned long long errors) {
+    printf("os_network_rx_bytes{interface=\"%s\"} %llu\n", interface, rxbytes);
+    printf("os_network_tx_bytes{interface=\"%s\"} %llu\n", interface, txbytes);
+    printf("os_network_errors{interface=\"%s\"} %llu\n", interface, errors);
+}
+
+void print_memory_metric(const char* metric, long value) {
+    printf("os_memory_%s_bytes %ld\n", metric, value);
+}
+
+int main() {
+    openlog("netbsd_exporter", LOG_PID, LOG_USER);
+    syslog(LOG_INFO, "Das Programm wurde aufgerufen.");
+
+    printf("HTTP/1.1 200 OK\r\n");
+    printf("Content-Type: text/plain\r\n\r\n");
+
+    int mib[3];
+    size_t size;
+    int i;
+
+    // Disk Space Metrics
+    struct statvfs* fsinfo;
+    int numfs;
+
+    numfs = getmntinfo(&fsinfo, MNT_WAIT);
+    if (numfs == -1) {
+        syslog(LOG_ERR, "getmntinfo failed");
+        return 1;
+    }
+
+    for (i = 0; i < numfs; i++) {
+	// Include only FFS filesystems in metrics
+	if(strcmp(fsinfo[i].f_fstypename,"ffs") != 0) {
+	    continue;
+        }
+	char *token;
+	token = strtok(fsinfo[i].f_mntfromname,"/");
+        if(token != NULL) { 
+            token = strtok(NULL, "/");
+	}
+
+	if(token == NULL) {
+	    syslog(LOG_ERR, "parsing dev failed");
+	    continue;
+        }
+        print_filesystem_metric("size", token, fsinfo[i].f_mntonname, fsinfo[i].f_blocks * fsinfo[i].f_frsize);
+        print_filesystem_metric("used", token, fsinfo[i].f_mntonname, (fsinfo[i].f_blocks - fsinfo[i].f_bfree) * fsinfo[i].f_frsize);
+        print_filesystem_metric("free", token, fsinfo[i].f_mntonname, fsinfo[i].f_bavail * fsinfo[i].f_frsize);
+    }
+
+    // CPU Load Metrics
+    double loadavg[3];
+    if(getloadavg(loadavg,3) != -1) {
+        print_load_metric("1", loadavg[0]);
+        print_load_metric("5", loadavg[1]);
+        print_load_metric("15", loadavg[2]);
+    } else {
+        syslog(LOG_ERR, "loadavg failed.");
+    }
+
+    // Network Card Metrics
+    struct ifaddrs* ifap, *ifa;
+    if (getifaddrs(&ifap) == 0) {
+        for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
+            if (ifa->ifa_addr == NULL || !(ifa->ifa_flags & IFF_UP))
+                continue;
+
+            if (ifa->ifa_addr->sa_family == AF_LINK) {
+                struct if_data* ifd = (struct if_data*)ifa->ifa_data;
+                print_network_metric(ifa->ifa_name, ifd->ifi_ibytes, ifd->ifi_obytes, ifd->ifi_ierrors + ifd->ifi_oerrors);
+            }
+        }
+        freeifaddrs(ifap);
+    } else {
+        syslog(LOG_ERR, "Fehler beim Abrufen der Netzwerkstatistiken.");
+    }
+
+    // Memory Metrics
+    int pagesize;
+    struct uvmexp_sysctl u;
+
+    // getpagesize() is obsolete, see manpage
+    pagesize = sysconf(_SC_PAGESIZE);
+    mib[0] = CTL_VM;
+    mib[1] = VM_UVMEXP2;
+    size = sizeof(struct uvmexp_sysctl);
+    if (sysctl(mib, 2, &u, &size, NULL, 0) == -1) {
+        syslog(LOG_ERR, "sysctl failed."); 
+        return 1;	
+    }
+    print_memory_metric("size", u.npages * pagesize);
+    print_memory_metric("free", u.free * pagesize);
+    print_memory_metric("active", u.active * pagesize);
+    print_memory_metric("inactive", u.inactive * pagesize);
+    print_memory_metric("paging", u.paging * pagesize);
+    print_memory_metric("wired", u.wired * pagesize);
+    print_memory_metric("swap_size", u.swpages * pagesize);
+    print_memory_metric("swap_used", u.swpginuse * pagesize);
+
+    // Disk IO
+    int ndrive;
+    mib[0] = CTL_HW;
+    mib[1] = HW_IOSTATS;
+    mib[2] = sizeof(struct io_sysctl);
+    if (sysctl(mib,3 , NULL, &size, NULL, 0) == -1) {
+        syslog(LOG_ERR, "No drives found"); 
+        return 1;	
+    }
+
+    ndrive = size / sizeof(struct io_stats);
+    if (size == 0) {
+        syslog(LOG_ERR, "No drives attached.");
+    } else {
+        drives = (struct io_sysctl *)malloc(size);
+        if (drives == NULL) {
+            syslog(LOG_ERR,"Memory allocation failure.");
+        }
+
+        /* Read the drive names and set initial selection. */
+        mib[0] = CTL_HW;                /* Should be still set from */
+        mib[1] = HW_IOSTATS;            /* ... above, but be safe... */
+        mib[2] = sizeof(struct io_sysctl);
+        if (sysctl(mib, 3, drives, &size, NULL, 0) == -1) {
+            syslog(LOG_ERR, "sysctl hw.iostats failed");
+        }
+        ndrive = size / sizeof(struct io_sysctl);
+        for (i = 0; i < ndrive; i++) {
+            print_disk_io_metric(drives[i].name, drives[i].rbytes, drives[i].wbytes);
+        }
+    }
+
+    closelog();
+    return 0;
+}