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#define _POSIX_C_SOURCE 200809L
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include "collector.h"
#include "scrape.h"
#include "util.h"
#ifndef XCOLLECTORS
#define XCOLLECTORS \
X(cpu) X(diskstats) X(filesystem) X(hwmon) \
X(meminfo) X(network) X(textfile) X(uname)
#endif
#define X(c) extern const struct collector c##_collector;
XCOLLECTORS
#undef X
#define X(c) &c##_collector,
static const struct collector *collectors[] = {
XCOLLECTORS
};
#undef X
#define NCOLLECTORS (sizeof collectors / sizeof *collectors)
enum tristate { flag_off = -1, flag_undef = 0, flag_on = 1 };
struct config {
const char *port;
};
struct handler_ctx {
struct {
enum tristate enabled;
struct slist *args;
struct slist **next_arg;
void *ctx;
} collectors[NCOLLECTORS];
};
static bool parse_args(int argc, char *argv[], struct config *cfg, struct handler_ctx *ctx);
static bool initialize(struct handler_ctx *ctx, int max_args);
static void handler(scrape_req *req, void *ctx_ptr);
int main(int argc, char *argv[]) {
struct config cfg = {
.port = "9100",
};
struct handler_ctx ctx;
if (!parse_args(argc, argv, &cfg, &ctx))
return 1;
if (!initialize(&ctx, argc > 0 ? argc - 1 : 0))
return 1;
if (!scrape_serve(cfg.port, handler, &ctx))
return 1;
return 0;
};
static bool parse_args(int argc, char *argv[], struct config *cfg, struct handler_ctx *ctx) {
for (size_t i = 0; i < NCOLLECTORS; i++) {
ctx->collectors[i].args = 0;
ctx->collectors[i].next_arg = &ctx->collectors[i].args;
ctx->collectors[i].enabled = flag_undef;
}
enum tristate enabled_default = flag_on;
for (int arg = 1; arg < argc; arg++) {
// check for collector arguments
for (size_t i = 0; i < NCOLLECTORS; i++) {
size_t name_len = strlen(collectors[i]->name);
if (strncmp(argv[arg], "--", 2) == 0
&& strncmp(argv[arg] + 2, collectors[i]->name, name_len) == 0
&& argv[arg][2 + name_len] == '-') {
char *carg = argv[arg] + 2 + name_len + 1;
if (strcmp(carg, "on") == 0) {
ctx->collectors[i].enabled = flag_on;
enabled_default = flag_off;
} else if (strcmp(carg, "off") == 0) {
ctx->collectors[i].enabled = flag_off;
} else if (collectors[i]->init && collectors[i]->has_args) {
ctx->collectors[i].next_arg = slist_append(ctx->collectors[i].next_arg, carg);
} else {
fprintf(stderr, "unknown argument: %s (collector %s takes no arguments)\n", argv[arg], collectors[i]->name);
return false;
}
goto next_arg;
}
}
// parse any non-collector arguments
// TODO --help
if (strncmp(argv[arg], "--port=", 7) == 0) {
cfg->port = &argv[arg][7];
goto next_arg;
}
fprintf(stderr, "unknown argument: %s\n", argv[arg]);
return false;
next_arg: ;
}
for (size_t i = 0; i < NCOLLECTORS; i++)
if (ctx->collectors[i].enabled == flag_undef)
ctx->collectors[i].enabled = enabled_default;
return true;
}
static bool initialize(struct handler_ctx *ctx, int max_args) {
int argc;
char *argv[max_args + 1];
for (size_t i = 0; i < NCOLLECTORS; i++) {
if (ctx->collectors[i].enabled == flag_on && collectors[i]->init) {
argc = 0;
for (struct slist *arg = ctx->collectors[i].args; arg && argc < max_args; arg = arg->next)
argv[argc++] = arg->data;
argv[argc] = 0;
ctx->collectors[i].ctx = collectors[i]->init(argc, argv);
if (!ctx->collectors[i].ctx) {
fprintf(stderr, "failed to initialize collector %s\n", collectors[i]->name);
return false;
}
}
}
return true;
}
static void handler(scrape_req *req, void *ctx_ptr) {
struct handler_ctx *ctx = ctx_ptr;
for (size_t c = 0; c < NCOLLECTORS; c++) {
if (ctx->collectors[c].enabled == flag_on)
collectors[c]->collect(req, ctx->collectors[c].ctx);
}
}
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