The branch stable/13 has been updated by rew: URL: https://cgit.FreeBSD.org/src/commit/?id=0cfae878f057692b9dc8c8c51630ce0a3a5dd4be
commit 0cfae878f057692b9dc8c8c51630ce0a3a5dd4be Author: Robert Wing <[email protected]> AuthorDate: 2021-10-08 01:00:27 +0000 Commit: Robert Wing <[email protected]> CommitDate: 2021-10-10 18:15:18 +0000 prometheus_sysctl_exporter(8): filter output using a regex Add two options, -i and -e, for filtering prometheus metrics. Each option takes a regular expression as an argument. The provided regex will be tested against the prometheus metric name. The -i option includes metrics matching the given regex. The -e option excludes metrics matching the given regex. Sponsored by: Modirum MDPay Sponsored by: Klara Inc. Reviewed by: 0mp, debdrup Differential Revision: https://reviews.freebsd.org/D32269 (cherry picked from commit 8ff2b52241400f2b5c2287b91e6e12b97ffd5773) --- .../prometheus_sysctl_exporter.8 | 18 ++++- .../prometheus_sysctl_exporter.c | 88 ++++++++++++++++------ 2 files changed, 80 insertions(+), 26 deletions(-) diff --git a/usr.sbin/prometheus_sysctl_exporter/prometheus_sysctl_exporter.8 b/usr.sbin/prometheus_sysctl_exporter/prometheus_sysctl_exporter.8 index f4ac44891ecb..7d73e3cab8cd 100644 --- a/usr.sbin/prometheus_sysctl_exporter/prometheus_sysctl_exporter.8 +++ b/usr.sbin/prometheus_sysctl_exporter/prometheus_sysctl_exporter.8 @@ -22,7 +22,7 @@ .\" SUCH DAMAGE. .\" .\" $FreeBSD$ -.Dd December 18, 2016 +.Dd October 7, 2021 .Dt PROMETHEUS_SYSCTL_EXPORTER 8 .Os .Sh NAME @@ -31,6 +31,8 @@ .Sh SYNOPSIS .Nm prometheus_sysctl_exporter .Op Fl dgh +.Op Fl e Ar pattern +.Op Fl i Ar pattern .Op Ar prefix ... .Sh DESCRIPTION Prometheus is a monitoring system that gathers metrics from its targets @@ -74,12 +76,26 @@ The following options are available: .Bl -tag -width indent .It Fl d Print descriptions of metrics when available. +.It Fl e Ar pattern +Same as +.Fl i , +except exclude metrics that match +.Ar pattern . .It Fl g Gzip compresses the HTTP response body. .It Fl h Precede the output with a HTTP response header. This flag is required when running this utility through .Xr inetd 8 . +.It Fl i Ar pattern +If specified, include metrics that match +.Ar pattern . +The format of +.Ar pattern +is to be a regular expression as described in +.Xr re_format 7 . +The provided regular expression is tested against the Prometheus +metric name. .El .Sh SEE ALSO .Xr cron 8 , diff --git a/usr.sbin/prometheus_sysctl_exporter/prometheus_sysctl_exporter.c b/usr.sbin/prometheus_sysctl_exporter/prometheus_sysctl_exporter.c index b1f24ddf203a..25e60f5dddbe 100644 --- a/usr.sbin/prometheus_sysctl_exporter/prometheus_sysctl_exporter.c +++ b/usr.sbin/prometheus_sysctl_exporter/prometheus_sysctl_exporter.c @@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$"); #include <err.h> #include <errno.h> #include <math.h> +#include <regex.h> #include <stdbool.h> #include <stdint.h> #include <stdio.h> @@ -44,6 +45,10 @@ __FBSDID("$FreeBSD$"); #include <unistd.h> #include <zlib.h> +/* Regular expressions for filtering output. */ +static regex_t inc_regex; +static regex_t exc_regex; + /* * Cursor for iterating over all of the system's sysctl OIDs. */ @@ -370,25 +375,27 @@ oid_get_name(const struct oid *o, struct oidname *on) on->oid = *o; } -/* Prints the name and labels of an OID to a file stream. */ +/* Populates the name and labels of an OID to a buffer. */ static void -oidname_print(const struct oidname *on, const struct oidformat *of, - FILE *fp) +oid_get_metric(const struct oidname *on, const struct oidformat *of, + char *metric, size_t mlen) { const char *name, *label; size_t i; - char separator; + char separator, buf[BUFSIZ]; /* Print the name of the metric. */ - fprintf(fp, "sysctl"); + snprintf(metric, mlen, "%s", "sysctl"); name = on->names; label = on->labels; for (i = 0; i < on->oid.len; ++i) { if (*label == '\0') { - fputc('_', fp); + strlcat(metric, "_", mlen); while (*name != '\0') { /* Map unsupported characters to underscores. */ - fputc(isalnum(*name) ? *name : '_', fp); + snprintf(buf, sizeof(buf), "%c", + isalnum(*name) ? *name : '_'); + strlcat(metric, buf, mlen); ++name; } } @@ -396,9 +403,9 @@ oidname_print(const struct oidname *on, const struct oidformat *of, label += strlen(label) + 1; } if (oidformat_is_temperature(of)) - fprintf(fp, "_celcius"); + strlcat(metric, "_celcius", mlen); else if (oidformat_is_timeval(of)) - fprintf(fp, "_seconds"); + strlcat(metric, "_seconds", mlen); /* Print the labels of the metric. */ name = on->names; @@ -410,21 +417,23 @@ oidname_print(const struct oidname *on, const struct oidformat *of, "abcdefghijklmnopqrstuvwxyz" "ABCDEFGHIJKLMNOPQRSTUVWXYZ" "0123456789_")] == '\0'); - fprintf(fp, "%c%s=\"", separator, label); + snprintf(buf, sizeof(buf), "%c%s=\"", separator, label); + strlcat(metric, buf, mlen); while (*name != '\0') { /* Escape backslashes and double quotes. */ if (*name == '\\' || *name == '"') - fputc('\\', fp); - fputc(*name++, fp); + strlcat(metric, "\\", mlen); + snprintf(buf, sizeof(buf), "%c", *name++); + strlcat(metric, buf, mlen); } - fputc('"', fp); + strlcat(metric, "\"", mlen); separator = ','; } name += strlen(name) + 1; label += strlen(label) + 1; } if (separator != '{') - fputc('}', fp); + strlcat(metric, "}", mlen); } /* Returns whether the OID name has any labels associated to it. */ @@ -483,16 +492,25 @@ oiddescription_print(const struct oiddescription *od, FILE *fp) static void oid_print(const struct oid *o, struct oidname *on, bool print_description, - FILE *fp) + bool exclude, bool include, FILE *fp) { struct oidformat of; struct oidvalue ov; struct oiddescription od; + char metric[BUFSIZ]; if (!oid_get_format(o, &of) || !oid_get_value(o, &of, &ov)) return; oid_get_name(o, on); + oid_get_metric(on, &of, metric, sizeof(metric)); + + if (exclude && regexec(&exc_regex, metric, 0, NULL, 0) == 0) + return; + + if (include && regexec(&inc_regex, metric, 0, NULL, 0) != 0) + return; + /* * Print the line with the description. Prometheus expects a * single unique description for every metric, which cannot be @@ -502,14 +520,14 @@ oid_print(const struct oid *o, struct oidname *on, bool print_description, if (print_description && !oidname_has_labels(on) && oid_get_description(o, &od)) { fprintf(fp, "# HELP "); - oidname_print(on, &of, fp); + fprintf(fp, "%s", metric); fputc(' ', fp); oiddescription_print(&od, fp); fputc('\n', fp); } /* Print the line with the value. */ - oidname_print(on, &of, fp); + fprintf(fp, "%s", metric); fputc(' ', fp); oidvalue_print(&ov, fp); fputc('\n', fp); @@ -539,8 +557,9 @@ static void usage(void) { - fprintf(stderr, - "usage: prometheus_sysctl_exporter [-dgh] [prefix ...]\n"); + fprintf(stderr, "%s", + "usage: prometheus_sysctl_exporter [-dgh] [-e pattern] [-i pattern]\n" + "\t[prefix ...]\n"); exit(1); } @@ -551,22 +570,41 @@ main(int argc, char *argv[]) char *http_buf; FILE *fp; size_t http_buflen; - int ch; - bool gzip_mode, http_mode, print_descriptions; + int ch, error; + bool exclude, include, gzip_mode, http_mode, print_descriptions; + char errbuf[BUFSIZ]; /* Parse command line flags. */ - gzip_mode = http_mode = print_descriptions = false; - while ((ch = getopt(argc, argv, "dgh")) != -1) { + include = exclude = gzip_mode = http_mode = print_descriptions = false; + while ((ch = getopt(argc, argv, "de:ghi:")) != -1) { switch (ch) { case 'd': print_descriptions = true; break; + case 'e': + error = regcomp(&exc_regex, optarg, REG_EXTENDED); + if (error != 0) { + regerror(error, &exc_regex, errbuf, sizeof(errbuf)); + errx(1, "bad regular expression '%s': %s", + optarg, errbuf); + } + exclude = true; + break; case 'g': gzip_mode = true; break; case 'h': http_mode = true; break; + case 'i': + error = regcomp(&inc_regex, optarg, REG_EXTENDED); + if (error != 0) { + regerror(error, &inc_regex, errbuf, sizeof(errbuf)); + errx(1, "bad regular expression '%s': %s", + optarg, errbuf); + } + include = true; + break; default: usage(); } @@ -590,7 +628,7 @@ main(int argc, char *argv[]) /* Print all OIDs. */ oid_get_root(&o); do { - oid_print(&o, &on, print_descriptions, fp); + oid_print(&o, &on, print_descriptions, exclude, include, fp); } while (oid_get_next(&o, &o)); } else { int i; @@ -602,7 +640,7 @@ main(int argc, char *argv[]) oid_get_by_name(&root, argv[i]); o = root; do { - oid_print(&o, &on, print_descriptions, fp); + oid_print(&o, &on, print_descriptions, exclude, include, fp); } while (oid_get_next(&o, &o) && oid_is_beneath(&o, &root)); }
