Add chart filtering parameter to the allmetrics API query (#12820)

* Add chart filtering in the allmetrics API call

* Fix compilation warnings

* Remove unnecessary function

* Update the documentation

* Apply suggestions from code review

* Check for filter instead of filter_string

* Do not check both - chart id and name for prometheus and shell formats

* Fix unit tests

Co-authored-by: Ilya Mashchenko <ilya@netdata.cloud>

2 files changed, 39 insertions, 20 deletions

diff --git a/exporting/prometheus/prometheus.c b/exporting/prometheus/prometheus.c
index 97c3a29f0e..dc8e870ef2 100644
--- a/exporting/prometheus/prometheus.c
+++ b/exporting/prometheus/prometheus.c
@@ -12,9 +12,10 @@
  *
  * @param instance an instance data structure.
  * @param st a chart.
+ * @param filter a simple pattern to match against.
  * @return Returns 1 if the chart can be sent, 0 otherwise.
  */
-inline int can_send_rrdset(struct instance *instance, RRDSET *st)
+inline int can_send_rrdset(struct instance *instance, RRDSET *st, SIMPLE_PATTERN *filter)
 {
 #ifdef NETDATA_INTERNAL_CHECKS
     RRDHOST *host = st->rrdhost;
@@ -27,19 +28,29 @@ inline int can_send_rrdset(struct instance *instance, RRDSET *st)
     if (unlikely(rrdset_flag_check(st, RRDSET_FLAG_EXPORTING_IGNORE)))
         return 0;
 
-    if (unlikely(!rrdset_flag_check(st, RRDSET_FLAG_EXPORTING_SEND))) {
-        // we have not checked this chart
-        if (simple_pattern_matches(instance->config.charts_pattern, st->id) ||
-            simple_pattern_matches(instance->config.charts_pattern, st->name))
-            rrdset_flag_set(st, RRDSET_FLAG_EXPORTING_SEND);
-        else {
-            rrdset_flag_set(st, RRDSET_FLAG_EXPORTING_IGNORE);
-            debug(
-                D_EXPORTING,
-                "EXPORTING: not sending chart '%s' of host '%s', because it is disabled for exporting.",
-                st->id,
-                host->hostname);
-            return 0;
+    if (filter) {
+        if (instance->config.options & EXPORTING_OPTION_SEND_NAMES) {
+            if (!simple_pattern_matches(filter, st->name))
+                return 0;
+        } else {
+            if (!simple_pattern_matches(filter, st->id))
+                return 0;
+        }
+    } else {
+        if (unlikely(!rrdset_flag_check(st, RRDSET_FLAG_EXPORTING_SEND))) {
+            // we have not checked this chart
+            if (simple_pattern_matches(instance->config.charts_pattern, st->id) ||
+                simple_pattern_matches(instance->config.charts_pattern, st->name))
+                rrdset_flag_set(st, RRDSET_FLAG_EXPORTING_SEND);
+            else {
+                rrdset_flag_set(st, RRDSET_FLAG_EXPORTING_IGNORE);
+                debug(
+                    D_EXPORTING,
+                    "EXPORTING: not sending chart '%s' of host '%s', because it is disabled for exporting.",
+                    st->id,
+                    host->hostname);
+                return 0;
+            }
         }
     }
 
@@ -480,6 +491,7 @@ static void generate_as_collected_prom_metric(BUFFER *wb, struct gen_parameters
  *
  * @param instance an instance data structure.
  * @param host a data collecting host.
+ * @param filter_string a simple pattern filter.
  * @param wb the buffer to fill with metrics.
  * @param prefix a prefix for every metric.
  * @param exporting_options options to configure what data is exported.
@@ -489,12 +501,14 @@ static void generate_as_collected_prom_metric(BUFFER *wb, struct gen_parameters
 static void rrd_stats_api_v1_charts_allmetrics_prometheus(
     struct instance *instance,
     RRDHOST *host,
+    const char *filter_string,
     BUFFER *wb,
     const char *prefix,
     EXPORTING_OPTIONS exporting_options,
     int allhosts,
     PROMETHEUS_OUTPUT_OPTIONS output_options)
 {
+    SIMPLE_PATTERN *filter = simple_pattern_create(filter_string, NULL, SIMPLE_PATTERN_EXACT);
     rrdhost_rdlock(host);
 
     char hostname[PROMETHEUS_ELEMENT_MAX + 1];
@@ -592,7 +606,7 @@ static void rrd_stats_api_v1_charts_allmetrics_prometheus(
     rrdset_foreach_read(st, host)
     {
 
-        if (likely(can_send_rrdset(instance, st))) {
+        if (likely(can_send_rrdset(instance, st, filter))) {
             rrdset_rdlock(st);
 
             char chart[PROMETHEUS_ELEMENT_MAX + 1];
@@ -777,6 +791,7 @@ static void rrd_stats_api_v1_charts_allmetrics_prometheus(
     }
 
     rrdhost_unlock(host);
+    simple_pattern_free(filter);
 }
 
 /**
@@ -850,6 +865,7 @@ static inline time_t prometheus_preparation(
  * Write metrics and auxiliary information for one host to a buffer.
  *
  * @param host a data collecting host.
+ * @param filter_string a simple pattern filter.
  * @param wb the buffer to write to.
  * @param server the name of a Prometheus server.
  * @param prefix a prefix for every metric.
@@ -858,6 +874,7 @@ static inline time_t prometheus_preparation(
  */
 void rrd_stats_api_v1_charts_allmetrics_prometheus_single_host(
     RRDHOST *host,
+    const char *filter_string,
     BUFFER *wb,
     const char *server,
     const char *prefix,
@@ -880,13 +897,14 @@ void rrd_stats_api_v1_charts_allmetrics_prometheus_single_host(
         output_options);
 
     rrd_stats_api_v1_charts_allmetrics_prometheus(
-        prometheus_exporter_instance, host, wb, prefix, exporting_options, 0, output_options);
+        prometheus_exporter_instance, host, filter_string, wb, prefix, exporting_options, 0, output_options);
 }
 
 /**
  * Write metrics and auxiliary information for all hosts to a buffer.
  *
  * @param host a data collecting host.
+ * @param filter_string a simple pattern filter.
  * @param wb the buffer to write to.
  * @param server the name of a Prometheus server.
  * @param prefix a prefix for every metric.
@@ -895,6 +913,7 @@ void rrd_stats_api_v1_charts_allmetrics_prometheus_single_host(
  */
 void rrd_stats_api_v1_charts_allmetrics_prometheus_all_hosts(
     RRDHOST *host,
+    const char *filter_string,
     BUFFER *wb,
     const char *server,
     const char *prefix,
@@ -920,7 +939,7 @@ void rrd_stats_api_v1_charts_allmetrics_prometheus_all_hosts(
     rrdhost_foreach_read(host)
     {
         rrd_stats_api_v1_charts_allmetrics_prometheus(
-            prometheus_exporter_instance, host, wb, prefix, exporting_options, 1, output_options);
+            prometheus_exporter_instance, host, filter_string, wb, prefix, exporting_options, 1, output_options);
     }
     rrd_unlock();
 }
diff --git a/exporting/prometheus/prometheus.h b/exporting/prometheus/prometheus.h
index 2f0845ce98..4b8860ded8 100644
--- a/exporting/prometheus/prometheus.h
+++ b/exporting/prometheus/prometheus.h
@@ -23,13 +23,13 @@ typedef enum prometheus_output_flags {
 } PROMETHEUS_OUTPUT_OPTIONS;
 
 extern void rrd_stats_api_v1_charts_allmetrics_prometheus_single_host(
-    RRDHOST *host, BUFFER *wb, const char *server, const char *prefix,
+    RRDHOST *host, const char *filter_string, BUFFER *wb, const char *server, const char *prefix,
     EXPORTING_OPTIONS exporting_options, PROMETHEUS_OUTPUT_OPTIONS output_options);
 extern void rrd_stats_api_v1_charts_allmetrics_prometheus_all_hosts(
-    RRDHOST *host, BUFFER *wb, const char *server, const char *prefix,
+    RRDHOST *host, const char *filter_string, BUFFER *wb, const char *server, const char *prefix,
     EXPORTING_OPTIONS exporting_options, PROMETHEUS_OUTPUT_OPTIONS output_options);
 
-int can_send_rrdset(struct instance *instance, RRDSET *st);
+int can_send_rrdset(struct instance *instance, RRDSET *st, SIMPLE_PATTERN *filter);
 size_t prometheus_name_copy(char *d, const char *s, size_t usable);
 size_t prometheus_label_copy(char *d, const char *s, size_t usable);
 char *prometheus_units_copy(char *d, const char *s, size_t usable, int showoldunits);