dyncfg v2 (#16702)

* split rrdfunctions streaming and progress

* simplified internal inline functions API

* split rrdfunctions inflight management

* split rrd functions exporters

* renames

* base dyncfg structure

* config pluginsd

* intercept dyncfg function calls

* loading and saving of dyncfg metadata and data

* save metadata and payload to a single file; added code to update the plugins with jobs and saved configs

* basic working unit test

* added payload to functions execution

* removed old dyncfg code that is not needed any more

* more cleanup

* cleanup sender for functions with payload

* dyncfg functions are not exposed as functions

* remaining work to avoid indexing the \0 terminating character in dictionary keys

* added back old dyncfg plugins.d commands as noop, to allow plugins continue working

* working api; working streaming;

* updated plugins.d documentation

* aclk and http api requests share the same header parsing logic

* added source type internal

* fixed crashes

* added god mode for tests

* fixes

* fixed messages

* save host machine guids to configs

* cleaner manipulation of supported commands

* the functions event loop for external plugins can now process dyncfg requests

* unified internal and external plugins dyncfg API

* Netdata serves schema requests from /etc/netdata/schema.d and /var/lib/netdata/conf.d/schema.d

* cleanup and various fixes; fixed bug in previous dyncfg implementation on streaming that was sending the paylod in a way that allowed other streaming commands to be multiplexed

* internals go to a separate header file

* fix duplicate ACLK requests sent by aclk queue mechanism

* use fstat instead of stat

* working api

* plugin actions renamed to create and delete; dyncfg files are removed only from user actions

* prevent deadlock by using the react callback

* fix for string_strndupz()

* better dyncfg unittests

* more tests at the unittests

* properly detect dyncfg functions

* hide config functions from the UI

* tree response improvements

* send the initial update with payload

* determine tty using stdout, not stderr

* changes to statuses, cleanup and the code to bring all business logic into interception

* do not crash when the status is empty

* functions now propagate the source of the requests to plugins

* avoid warning about unused functions

* in the count at items for attention, do not count the orphan entries

* save source into dyncfg

* make the list null terminated

* fixed invalid comparison

* prevent memory leak on duplicated headers; log x-forwarded-for

* more unit tests

* added dyncfg unittests into the default unittests

* more unit tests and fixes

* more unit tests and fixes

* fix dictionary unittests

* config functions require admin access

2 files changed, 22 insertions, 0 deletions

diff --git a/libnetdata/string/string.c b/libnetdata/string/string.c
index 81c8b3401f..0b4a6470d7 100644
--- a/libnetdata/string/string.c
+++ b/libnetdata/string/string.c
@@ -307,6 +307,25 @@ STRING *string_strdupz(const char *str) {
     return string;
 }
 
+STRING *string_strndupz(const char *str, size_t len) {
+    if(unlikely(!str || !*str || !len)) return NULL;
+
+#ifdef NETDATA_INTERNAL_CHECKS
+    uint8_t partition = string_partition_str(str);
+#endif
+
+    char buf[len + 1];
+    memcpy(buf, str, len);
+    buf[len] = '\0';
+
+    STRING *string = string_index_search(buf, len + 1);
+    while(!string)
+        string = string_index_insert(buf, len + 1);
+
+    string_stats_atomic_increment(partition, active_references);
+    return string;
+}
+
 void string_freez(STRING *string) {
     if(unlikely(!string)) return;
 
diff --git a/libnetdata/string/string.h b/libnetdata/string/string.h
index ba0e3876bc..f2ff9666ca 100644
--- a/libnetdata/string/string.h
+++ b/libnetdata/string/string.h
@@ -8,7 +8,10 @@
 // STRING implementation
 
 typedef struct netdata_string STRING;
+
 STRING *string_strdupz(const char *str);
+STRING *string_strndupz(const char *str, size_t len);
+
 STRING *string_dup(STRING *string);
 void string_freez(STRING *string);
 size_t string_strlen(STRING *string);