Allow netdata plugins to expose functions for querying more information about specific charts (#13720)

* function renames and code cleanup in popen.c; no actual code changes

* netdata popen() now opens both child process stdin and stdout and returns FILE * for both

* pass both input and output to parser structures

* updated rrdset to call custom functions

* RRDSET FUNCTION leading calls for both sync and async operation

* put RRDSET functions to a separate file

* added format and timeout at function definition

* support for synchronous (internal plugins) and asynchronous (external plugins and children) functions

* /api/v1/function endpoint

* functions are now attached to the host and there is a dictionary view per chart

* functions implemented at plugins.d

* remove the defer until keyword hook from plugins.d when it is done

* stream sender implementation of functions

* sanitization of all functions so that certain characters are only allowed

* strictier sanitization

* common max size

* 1st working plugins.d example

* always init inflight dictionary

* properly destroy dictionaries to avoid parallel insertion of items

* add more debugging on disconnection reasons

* add more debugging on disconnection reasons again

* streaming receiver respects newlines

* dont use the same fp for both streaming receive and send

* dont free dbengine memory with internal checks

* make sender proceed in the buffer

* added timing info and garbage collection at plugins.d

* added info about routing nodes

* added info about routing nodes with delay

* added more info about delays

* added more info about delays again

* signal sending thread to wake up

* streaming version labeling and commented code to support capabilities

* added functions to /api/v1/data, /api/v1/charts, /api/v1/chart, /api/v1/info

* redirect top output to stdout

* address coverity findings

* fix resource leaks of popen

* log attempts to connect to individual destinations

* better messages

* properly parse destinations

* try to find a function from the most matching to the least matching

* log added streaming destinations

* rotate destinations bypassing a node in the middle that does not accept our connection

* break the loops properly

* use typedef to define callbacks

* capabilities negotiation during streaming

* functions exposed upstream based on capabilities; compression disabled per node persisting reconnects; always try to connect with all capabilities

* restore functionality to lookup functions

* better logging of capabilities

* remove old versions from capabilities when a newer version is there

* fix formatting

* optimization for plugins.d rrdlabels to avoid creating and destructing dictionaries all the time

* delayed health initialization for rrddim and rrdset

* cleanup health initialization

* fix for popen() not returning the right value

* add health worker jobs for initializing rrdset and rrddim

* added content type support for functions; apps.plugin permanent function to display all the processes

* fixes for functions parameters parsing in apps.plugin

* fix for process matching in apps.plugiin

* first working function for apps.plugin

* Dashboard ACL is disabled for functions; Function errors are all in JSON format

* apps.plugin function processes returns json table

* use json_escape_string() to escape message

* fix formatting

* apps.plugin exposes all its metrics to function processes

* fix json formatting when filtering out some rows

* reopen the internal pipe of rrdpush in case of errors

* misplaced statement

* do not use buffer->len

* support for GLOBAL functions (functions that are not linked to a chart

* added /api/v1/functions endpoint; removed format from the FUNCTIONS api;

* swagger documentation about the new api end points

* added plugins.d documentation about functions

* never re-close a file

* remove uncessesary ifdef

* fixed issues identified by codacy

* fix for null label value

* make edit-config copy-and-paste friendly

* Revert "make edit-config copy-and-paste friendly"

This reverts commit 54500c0e0a97f65a0c66c4d34e966f6a9056698e.

* reworked sender handshake to fix coverity findings

* timeout is zero, for both send_timeout() and recv_timeout()

* properly detect that parent closed the socket

* support caching of function responses; limit function response to 10MB; added protection from malformed function responses

* disabled excessive logging

* added units to apps.plugin function processes and normalized all values to be human readable

* shorter field names

* fixed issues reported

* fixed apps.plugin error response; tested that pluginsd can properly handle faulty responses

* use double linked list macros for double linked list management

* faster apps.plugin function printing by minimizing file operations

* added memory percentage

* fix compatibility issues with older compilers and FreeBSD

* rrdpush sender code cleanup; rrhost structure cleanup from sender flags and variables;

* fix letftover variable in ifdef

* apps.plugin: do not call detach from the thread; exit immediately when input is broken

* exclude AR charts from health

* flush cleaner; prefer sender output

* clarity

* do not fill the cbuffer if not connected

* fix

* dont enabled host->sender if streaming is not enabled; send host label updates to parent;

* functions are only available through ACLK

* Prepared statement reports only in dev mode

* fix AR chart detection

* fix for streaming not being enabling itself

* more cleanup of sender and receiver structures

* moved read-only flags and configuration options to rrdhost->options

* fixed merge with master

* fix for incomplete rename

* prevent service thread from working on charts that are being collected

Co-authored-by: Stelios Fragkakis <52996999+stelfrag@users.noreply.github.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/web/server/web_client.c b/web/server/web_client.c
index 9865ce671b..ff485384f7 100644
--- a/web/server/web_client.c
+++ b/web/server/web_client.c
@@ -1018,7 +1018,7 @@ static inline HTTP_VALIDATION http_request_validate(struct web_client *w) {
                 // TODO -- ideally we we should avoid copying buffers around
                 snprintfz(w->last_url, NETDATA_WEB_REQUEST_URL_SIZE, "%s%s", w->decoded_url,  w->decoded_query_string);
 #ifdef ENABLE_HTTPS
-                if ( (!web_client_check_unix(w)) && (netdata_srv_ctx) ) {
+                if ( (!web_client_check_unix(w)) && (netdata_ssl_srv_ctx) ) {
                     if ((w->ssl.conn) && ((w->ssl.flags & NETDATA_SSL_NO_HANDSHAKE) && (web_client_is_using_ssl_force(w) || web_client_is_using_ssl_default(w)) && (w->mode != WEB_CLIENT_MODE_STREAM))  ) {
                         w->header_parse_tries = 0;
                         w->header_parse_last_size = 0;
@@ -1054,7 +1054,7 @@ static inline ssize_t web_client_send_data(struct web_client *w,const void *buf,
 {
     ssize_t bytes;
 #ifdef ENABLE_HTTPS
-    if ( (!web_client_check_unix(w)) && (netdata_srv_ctx) ) {
+    if ( (!web_client_check_unix(w)) && (netdata_ssl_srv_ctx) ) {
         if ( ( w->ssl.conn ) && ( !w->ssl.flags ) ){
             bytes = SSL_write(w->ssl.conn,buf, len) ;
         } else {
@@ -1211,7 +1211,7 @@ static inline void web_client_send_http_header(struct web_client *w) {
     size_t count = 0;
     ssize_t bytes;
 #ifdef ENABLE_HTTPS
-    if ( (!web_client_check_unix(w)) && (netdata_srv_ctx) ) {
+    if ( (!web_client_check_unix(w)) && (netdata_ssl_srv_ctx) ) {
            if ( ( w->ssl.conn ) && ( !w->ssl.flags ) ){
                 while((bytes = SSL_write(w->ssl.conn, buffer_tostring(w->response.header_output), buffer_strlen(w->response.header_output))) < 0) {
                     count++;
@@ -1915,7 +1915,7 @@ ssize_t web_client_receive(struct web_client *w)
     buffer_need_bytes(w->response.data, NETDATA_WEB_REQUEST_RECEIVE_SIZE);
 
 #ifdef ENABLE_HTTPS
-    if ( (!web_client_check_unix(w)) && (netdata_srv_ctx) ) {
+    if ( (!web_client_check_unix(w)) && (netdata_ssl_srv_ctx) ) {
         if ( ( w->ssl.conn ) && (!w->ssl.flags)) {
             bytes = SSL_read(w->ssl.conn, &w->response.data->buffer[w->response.data->len], (size_t) (left - 1));
         }else {