#include <microhttpd.h>
#ifndef PROMETHEUS_DEFAULT_STALENESS_DELTA
-#define PROMETHEUS_DEFAULT_STALENESS_DELTA TIME_T_TO_CDTIME_T(300)
+#define PROMETHEUS_DEFAULT_STALENESS_DELTA TIME_T_TO_CDTIME_T_STATIC(300)
#endif
#define VARINT_UINT32_BYTES 5
pthread_mutex_unlock(&metrics_lock);
}
+static char const *escape_label_value(char *buffer, size_t buffer_size,
+ char const *value) {
+ /* shortcut for values that don't need escaping. */
+ if (strpbrk(value, "\n\"\\") == NULL)
+ return value;
+
+ size_t value_len = strlen(value);
+ size_t buffer_len = 0;
+
+ for (size_t i = 0; i < value_len; i++) {
+ switch (value[i]) {
+ case '\n':
+ case '"':
+ case '\\':
+ if ((buffer_size - buffer_len) < 3) {
+ break;
+ }
+ buffer[buffer_len] = '\\';
+ buffer[buffer_len + 1] = (value[i] == '\n') ? 'n' : value[i];
+ buffer_len += 2;
+ break;
+
+ default:
+ if ((buffer_size - buffer_len) < 2) {
+ break;
+ }
+ buffer[buffer_len] = value[i];
+ buffer_len++;
+ break;
+ }
+ }
+
+ assert(buffer_len < buffer_size);
+ buffer[buffer_len] = 0;
+ return buffer;
+}
+
/* format_labels formats a metric's labels in Prometheus-compatible format. This
* format looks like this:
*
assert(m->n_label >= 1);
assert(m->n_label <= 3);
-#define LABEL_BUFFER_SIZE (2 * DATA_MAX_NAME_LEN + 4)
+#define LABEL_KEY_SIZE DATA_MAX_NAME_LEN
+#define LABEL_VALUE_SIZE (2 * DATA_MAX_NAME_LEN - 1)
+#define LABEL_BUFFER_SIZE (LABEL_KEY_SIZE + LABEL_VALUE_SIZE + 4)
char *labels[3] = {
(char[LABEL_BUFFER_SIZE]){0}, (char[LABEL_BUFFER_SIZE]){0},
(char[LABEL_BUFFER_SIZE]){0},
};
- for (size_t i = 0; i < m->n_label; i++)
+ /* N.B.: the label *names* are hard-coded by this plugin and therefore we
+ * know that they are sane. */
+ for (size_t i = 0; i < m->n_label; i++) {
+ char value[LABEL_VALUE_SIZE];
ssnprintf(labels[i], LABEL_BUFFER_SIZE, "%s=\"%s\"", m->label[i]->name,
- m->label[i]->value);
+ escape_label_value(value, sizeof(value), m->label[i]->value));
+ }
strjoin(buffer, buffer_size, labels, m->n_label, ",");
return buffer;
else
format_text(buffer);
+#if defined(MHD_VERSION) && MHD_VERSION >= 0x00090500
+ struct MHD_Response *res = MHD_create_response_from_buffer(
+ simple.len, simple.data, MHD_RESPMEM_MUST_COPY);
+#else
struct MHD_Response *res = MHD_create_response_from_data(
simple.len, simple.data, /* must_free = */ 0, /* must_copy = */ 1);
+#endif
MHD_add_response_header(res, MHD_HTTP_HEADER_CONTENT_TYPE,
want_proto ? CONTENT_TYPE_PROTO : CONTENT_TYPE_TEXT);
sfree(msg);
}
-/* label_pair_create allocates and initializes a new label pair. */
-static Io__Prometheus__Client__LabelPair *label_pair_create(char const *name,
- char const *value) {
- Io__Prometheus__Client__LabelPair *msg = calloc(1, sizeof(*msg));
- if (msg == NULL)
+/* label_pair_clone allocates and initializes a new label pair. */
+static Io__Prometheus__Client__LabelPair *
+label_pair_clone(Io__Prometheus__Client__LabelPair const *orig) {
+ Io__Prometheus__Client__LabelPair *copy = calloc(1, sizeof(*copy));
+ if (copy == NULL)
return NULL;
- io__prometheus__client__label_pair__init(msg);
+ io__prometheus__client__label_pair__init(copy);
- msg->name = strdup(name);
- msg->value = strdup(value);
- if ((msg->name == NULL) || (msg->value == NULL)) {
- label_pair_destroy(msg);
+ copy->name = strdup(orig->name);
+ copy->value = strdup(orig->value);
+ if ((copy->name == NULL) || (copy->value == NULL)) {
+ label_pair_destroy(copy);
return NULL;
}
- return msg;
+ return copy;
}
/* metric_destroy frees the memory used by a metric. */
sfree(msg);
}
-/* metric_add_labels adds the labels that identify this metric to m.
- * The logic is copied from the "collectd_exporter". Essentially, the labels
- * contain the hostname, the plugin instance and the type instance of a
- * value_list_t. */
-static int metric_add_labels(Io__Prometheus__Client__Metric *m,
- value_list_t const *vl) {
- size_t n_label = 1;
- if (strlen(vl->plugin_instance) != 0)
- n_label++;
- if (strlen(vl->type_instance) != 0)
- n_label++;
-
- m->label = calloc(n_label, sizeof(*m->label));
- if (m->label == NULL)
- return ENOMEM;
-
- if (strlen(vl->plugin_instance) != 0) {
- m->label[m->n_label] = label_pair_create(vl->plugin, vl->plugin_instance);
- m->n_label++;
- }
-
- if (strlen(vl->type_instance) != 0) {
- char const *name = "type";
- if (strlen(vl->plugin_instance) == 0)
- name = vl->plugin;
-
- m->label[m->n_label] = label_pair_create(name, vl->type_instance);
- m->n_label++;
- }
-
- m->label[m->n_label] = label_pair_create("instance", vl->host);
- m->n_label++;
-
- for (size_t i = 0; i < m->n_label; i++) {
- if (m->label[i] == NULL)
- return ENOMEM;
- }
-
- return 0;
-}
-
/* metric_cmp compares two metrics. It's prototype makes it easy to use with
* qsort(3) and bsearch(3). */
static int metric_cmp(void const *a, void const *b) {
return 1;
/* Prometheus does not care about the order of labels. All labels in this
- * plugin are created by metric_add_labels(), though, and therefore always
+ * plugin are created by METRIC_ADD_LABELS(), though, and therefore always
* appear in the same order. We take advantage of this and simplify the check
- * by making sure all labels are the same in each position. */
+ * by making sure all labels are the same in each position.
+ *
+ * We also only need to check the label values, because the label names are
+ * the same for all metrics in a metric family.
+ *
+ * 3 labels:
+ * [0] $plugin="$plugin_instance" => $plugin is the same within a family
+ * [1] type="$type_instance" => "type" is a static string
+ * [2] instance="$host" => "instance" is a static string
+ *
+ * 2 labels, variant 1:
+ * [0] $plugin="$plugin_instance" => $plugin is the same within a family
+ * [1] instance="$host" => "instance" is a static string
+ *
+ * 2 labels, variant 2:
+ * [0] $plugin="$type_instance" => $plugin is the same within a family
+ * [1] instance="$host" => "instance" is a static string
+ *
+ * 1 label:
+ * [1] instance="$host" => "instance" is a static string
+ */
for (size_t i = 0; i < m_a->n_label; i++) {
- int status = strcmp(m_a->label[i]->name, m_b->label[i]->name);
+ int status = strcmp(m_a->label[i]->value, m_b->label[i]->value);
if (status != 0)
return status;
- status = strcmp(m_a->label[i]->value, m_b->label[i]->value);
- if (status != 0)
- return status;
+#if COLLECT_DEBUG
+ assert(strcmp(m_a->label[i]->name, m_b->label[i]->name) == 0);
+#endif
}
return 0;
}
-/* metric_create allocates and initializes a new metric. */
-static Io__Prometheus__Client__Metric *metric_create(value_list_t const *vl) {
- Io__Prometheus__Client__Metric *msg = calloc(1, sizeof(*msg));
- if (msg == NULL)
+#define METRIC_INIT \
+ &(Io__Prometheus__Client__Metric) { \
+ .label = \
+ (Io__Prometheus__Client__LabelPair *[]){ \
+ &(Io__Prometheus__Client__LabelPair){ \
+ .name = NULL, \
+ }, \
+ &(Io__Prometheus__Client__LabelPair){ \
+ .name = NULL, \
+ }, \
+ &(Io__Prometheus__Client__LabelPair){ \
+ .name = NULL, \
+ }, \
+ }, \
+ .n_label = 0, \
+ }
+
+#define METRIC_ADD_LABELS(m, vl) \
+ do { \
+ if (strlen((vl)->plugin_instance) != 0) { \
+ (m)->label[(m)->n_label]->name = (char *)(vl)->plugin; \
+ (m)->label[(m)->n_label]->value = (char *)(vl)->plugin_instance; \
+ (m)->n_label++; \
+ } \
+ \
+ if (strlen((vl)->type_instance) != 0) { \
+ (m)->label[(m)->n_label]->name = "type"; \
+ if (strlen((vl)->plugin_instance) == 0) \
+ (m)->label[(m)->n_label]->name = (char *)(vl)->plugin; \
+ (m)->label[(m)->n_label]->value = (char *)(vl)->type_instance; \
+ (m)->n_label++; \
+ } \
+ \
+ (m)->label[(m)->n_label]->name = "instance"; \
+ (m)->label[(m)->n_label]->value = (char *)(vl)->host; \
+ (m)->n_label++; \
+ } while (0)
+
+/* metric_clone allocates and initializes a new metric based on orig. */
+static Io__Prometheus__Client__Metric *
+metric_clone(Io__Prometheus__Client__Metric const *orig) {
+ Io__Prometheus__Client__Metric *copy = calloc(1, sizeof(*copy));
+ if (copy == NULL)
return NULL;
- io__prometheus__client__metric__init(msg);
+ io__prometheus__client__metric__init(copy);
- if (metric_add_labels(msg, vl) != 0) {
- metric_destroy(msg);
+ copy->n_label = orig->n_label;
+ copy->label = calloc(copy->n_label, sizeof(*copy->label));
+ if (copy->label == NULL) {
+ sfree(copy);
return NULL;
}
- return msg;
+ for (size_t i = 0; i < copy->n_label; i++) {
+ copy->label[i] = label_pair_clone(orig->label[i]);
+ if (copy->label[i] == NULL) {
+ metric_destroy(copy);
+ return NULL;
+ }
+ }
+
+ return copy;
}
/* metric_update stores the new value and timestamp in m. */
static int
metric_family_delete_metric(Io__Prometheus__Client__MetricFamily *fam,
value_list_t const *vl) {
- Io__Prometheus__Client__Metric *key = metric_create(vl);
- if (key == NULL)
- return ENOMEM;
+ Io__Prometheus__Client__Metric *key = METRIC_INIT;
+ METRIC_ADD_LABELS(key, vl);
size_t i;
for (i = 0; i < fam->n_metric; i++) {
((fam->n_metric - 1) - i) * sizeof(fam->metric[i]));
fam->n_metric--;
+ if (fam->n_metric == 0) {
+ sfree(fam->metric);
+ return 0;
+ }
+
Io__Prometheus__Client__Metric **tmp =
realloc(fam->metric, fam->n_metric * sizeof(*fam->metric));
- if ((tmp != NULL) || (fam->n_metric == 0))
+ if (tmp != NULL)
fam->metric = tmp;
return 0;
static Io__Prometheus__Client__Metric *
metric_family_get_metric(Io__Prometheus__Client__MetricFamily *fam,
value_list_t const *vl) {
- Io__Prometheus__Client__Metric *key = metric_create(vl);
- if (key == NULL)
- return NULL;
+ Io__Prometheus__Client__Metric *key = METRIC_INIT;
+ METRIC_ADD_LABELS(key, vl);
/* Metrics are sorted in metric_family_add_metric() so that we can do a binary
* search here. */
&key, fam->metric, fam->n_metric, sizeof(*fam->metric), metric_cmp);
if (m != NULL) {
- metric_destroy(key);
return *m;
}
+ Io__Prometheus__Client__Metric *new_metric = metric_clone(key);
+ if (new_metric == NULL)
+ return NULL;
+
DEBUG("write_prometheus plugin: created new metric in family");
- int status = metric_family_add_metric(fam, key);
+ int status = metric_family_add_metric(fam, new_metric);
if (status != 0) {
- metric_destroy(key);
+ metric_destroy(new_metric);
return NULL;
}
- return key;
+ return new_metric;
}
/* metric_family_update looks up the matching metric in a metric family,
if (m == NULL)
return -1;
- return metric_update(m, vl->values[ds_index], ds->ds[ds_index].type, vl->time,
- vl->interval);
+ return metric_update(m, vl->values[ds_index], ds->ds[ds_index].type,
+ vl->time, vl->interval);
}
/* metric_family_destroy frees the memory used by a metric family. */
/* metric_family_get looks up the matching metric family, allocating it if
* necessary. */
static Io__Prometheus__Client__MetricFamily *
-metric_family_get(data_set_t const *ds, value_list_t const *vl,
- size_t ds_index) {
+metric_family_get(data_set_t const *ds, value_list_t const *vl, size_t ds_index,
+ _Bool allocate) {
char *name = metric_family_name(ds, vl, ds_index);
if (name == NULL) {
ERROR("write_prometheus plugin: Allocating metric family name failed.");
return fam;
}
+ if (!allocate) {
+ sfree(name);
+ return NULL;
+ }
+
fam = metric_family_create(name, ds, vl, ds_index);
if (fam == NULL) {
ERROR("write_prometheus plugin: Allocating metric family failed.");
pthread_mutex_lock(&metrics_lock);
for (size_t i = 0; i < ds->ds_num; i++) {
- Io__Prometheus__Client__MetricFamily *fam = metric_family_get(ds, vl, i);
+ Io__Prometheus__Client__MetricFamily *fam =
+ metric_family_get(ds, vl, i, /* allocate = */ 1);
if (fam == NULL)
continue;
pthread_mutex_lock(&metrics_lock);
for (size_t i = 0; i < ds->ds_num; i++) {
- Io__Prometheus__Client__MetricFamily *fam = metric_family_get(ds, vl, i);
+ Io__Prometheus__Client__MetricFamily *fam =
+ metric_family_get(ds, vl, i, /* allocate = */ 0);
if (fam == NULL)
continue;
ERROR("write_prometheus plugin: Deleting a metric in family \"%s\" "
"failed with status %d",
fam->name, status);
+
continue;
}
/* user data = */ NULL);
plugin_register_shutdown("write_prometheus", prom_shutdown);
}
-
-/* vim: set sw=2 sts=2 et fdm=marker : */
projects / collectd.git / blobdiff