Easily disable alarms, by persisting the silencers configuration (#6360)

This PR was created to fix #3414, here I am completing the job initiated by Christopher, among the newest features that we are bring we have

JSON inside the core - We are bringing to the core the capacity to work with JSON files, this is available either using the JSON-C library case it is present in the system or using JSMN library that was incorporated to our core. The preference is to have JSON-C, because it is a more complete library, but case the user does not have the library installed we are keeping the JSMN for we do not lose the feature.
Health LIST - We are bringing more one command to the Health API, now with the LIST it is possible to get in JSON format the alarms active with Netdata.
Health reorganized - Previously we had duplicated code in different files, this PR is fixing this (Thanks @cakrit !), the Health is now better organized.
Removing memory leak - The first implementation of the json.c was creating SILENCERS without to link it in anywhere. Now it has been linked properly.
Script updated - We are bringing some changes to the script that tests the Health.
This PR also fixes the race condition created by the previous new position of the SILENCERS creation, I had to move it to daemon/main.c, because after various tests, it was confirmed that the error could happen in different parts of the code, case it was not initialized before the threads starts.

Component Name
health directory
health-cmd

Additional Information
Fixes #6356 and #3414

11 files changed, 1270 insertions, 0 deletions

diff --git a/libnetdata/Makefile.am b/libnetdata/Makefile.am
index d2710f0a3e..87f12b32cb 100644
--- a/libnetdata/Makefile.am
+++ b/libnetdata/Makefile.am
@@ -11,6 +11,8 @@ SUBDIRS = \
     config \
     dictionary \
     eval \
+    json \
+    health \
     locks \
     log \
     popen \
diff --git a/libnetdata/health/Makefile.am b/libnetdata/health/Makefile.am
new file mode 100644
index 0000000000..9b7995f175
--- /dev/null
+++ b/libnetdata/health/Makefile.am
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+
+dist_noinst_DATA = \
+	$(NULL)
diff --git a/libnetdata/health/health.c b/libnetdata/health/health.c
new file mode 100644
index 0000000000..b93de8b93e
--- /dev/null
+++ b/libnetdata/health/health.c
@@ -0,0 +1,170 @@
+#include "health.h"
+
+/**
+ * Create Silencer
+ *
+ * Allocate a new silencer to Netdata.
+ *
+ * @return It returns the address off the silencer on success and NULL otherwise
+ */
+SILENCER *create_silencer(void) {
+    SILENCER *t = callocz(1, sizeof(SILENCER));
+    debug(D_HEALTH, "HEALTH command API: Created empty silencer");
+
+    return t;
+}
+
+/**
+ * Health Silencers add
+ *
+ * Add more one silencer to the list of silenecers.
+ *
+ * @param silencer
+ */
+void health_silencers_add(SILENCER *silencer) {
+    // Add the created instance to the linked list in silencers
+    silencer->next = silencers->silencers;
+    silencers->silencers = silencer;
+    debug(D_HEALTH, "HEALTH command API: Added silencer %s:%s:%s:%s:%s", silencer->alarms,
+          silencer->charts, silencer->contexts, silencer->hosts, silencer->families
+    );
+}
+
+/**
+ * Silencers Add Parameter
+ *
+ * Create a new silencer and adjust the variables
+ *
+ * @param silencer a pointer to the silencer that will be adjusted
+ * @param key the key value sent by client
+ * @param value the value sent to the key
+ *
+ * @return It returns the silencer configured on success and NULL otherwise
+ */
+SILENCER *health_silencers_addparam(SILENCER *silencer, char *key, char *value) {
+    static uint32_t
+            hash_alarm = 0,
+            hash_template = 0,
+            hash_chart = 0,
+            hash_context = 0,
+            hash_host = 0,
+            hash_families = 0;
+
+    if (unlikely(!hash_alarm)) {
+        hash_alarm = simple_uhash(HEALTH_ALARM_KEY);
+        hash_template = simple_uhash(HEALTH_TEMPLATE_KEY);
+        hash_chart = simple_uhash(HEALTH_CHART_KEY);
+        hash_context = simple_uhash(HEALTH_CONTEXT_KEY);
+        hash_host = simple_uhash(HEALTH_HOST_KEY);
+        hash_families = simple_uhash(HEALTH_FAMILIES_KEY);
+    }
+
+    uint32_t hash = simple_uhash(key);
+    if (unlikely(silencer == NULL)) {
+        if (
+                (hash == hash_alarm && !strcasecmp(key, HEALTH_ALARM_KEY)) ||
+                (hash == hash_template && !strcasecmp(key, HEALTH_TEMPLATE_KEY)) ||
+                (hash == hash_chart && !strcasecmp(key, HEALTH_CHART_KEY)) ||
+                (hash == hash_context && !strcasecmp(key, HEALTH_CONTEXT_KEY)) ||
+                (hash == hash_host && !strcasecmp(key, HEALTH_HOST_KEY)) ||
+                (hash == hash_families && !strcasecmp(key, HEALTH_FAMILIES_KEY))
+                ) {
+            silencer = create_silencer();
+            if(!silencer) {
+                error("Cannot add a new silencer to Netdata");
+                return NULL;
+            }
+        }
+    }
+
+    if (hash == hash_alarm && !strcasecmp(key, HEALTH_ALARM_KEY)) {
+        silencer->alarms = strdupz(value);
+        silencer->alarms_pattern = simple_pattern_create(silencer->alarms, NULL, SIMPLE_PATTERN_EXACT);
+    } else if (hash == hash_chart && !strcasecmp(key, HEALTH_CHART_KEY)) {
+        silencer->charts = strdupz(value);
+        silencer->charts_pattern = simple_pattern_create(silencer->charts, NULL, SIMPLE_PATTERN_EXACT);
+    } else if (hash == hash_context && !strcasecmp(key, HEALTH_CONTEXT_KEY)) {
+        silencer->contexts = strdupz(value);
+        silencer->contexts_pattern = simple_pattern_create(silencer->contexts, NULL, SIMPLE_PATTERN_EXACT);
+    } else if (hash == hash_host && !strcasecmp(key, HEALTH_HOST_KEY)) {
+        silencer->hosts = strdupz(value);
+        silencer->hosts_pattern = simple_pattern_create(silencer->hosts, NULL, SIMPLE_PATTERN_EXACT);
+    } else if (hash == hash_families && !strcasecmp(key, HEALTH_FAMILIES_KEY)) {
+        silencer->families = strdupz(value);
+        silencer->families_pattern = simple_pattern_create(silencer->families, NULL, SIMPLE_PATTERN_EXACT);
+    }
+
+    return silencer;
+}
+
+/**
+ * JSON Read Callback
+ *
+ * Callback called by netdata to create the silencer.
+ *
+ * @param e the main json structure
+ *
+ * @return It always return 0.
+ */
+int health_silencers_json_read_callback(JSON_ENTRY *e)
+{
+    switch(e->type) {
+        case JSON_OBJECT:
+#ifndef ENABLE_JSONC
+            e->callback_function = health_silencers_json_read_callback;
+            if(e->name && strcmp(e->name,"")) {
+                // init silencer
+                debug(D_HEALTH, "JSON: Got object with a name, initializing new silencer for %s",e->name);
+#endif
+            e->callback_data = create_silencer();
+            if(e->callback_data) {
+                health_silencers_add(e->callback_data);
+            }
+#ifndef ENABLE_JSONC
+            }
+#endif
+            break;
+
+        case JSON_ARRAY:
+            e->callback_function = health_silencers_json_read_callback;
+            break;
+
+        case JSON_STRING:
+            if(!strcmp(e->name,"type")) {
+                debug(D_HEALTH, "JSON: Processing type=%s",e->data.string);
+                if (!strcmp(e->data.string,"SILENCE")) silencers->stype = STYPE_SILENCE_NOTIFICATIONS;
+                else if (!strcmp(e->data.string,"DISABLE")) silencers->stype = STYPE_DISABLE_ALARMS;
+            } else {
+                debug(D_HEALTH, "JSON: Adding %s=%s", e->name, e->data.string);
+                health_silencers_addparam(e->callback_data, e->name, e->data.string);
+            }
+            break;
+
+        case JSON_BOOLEAN:
+            debug(D_HEALTH, "JSON: Processing all_alarms");
+            silencers->all_alarms=e->data.boolean?1:0;
+            break;
+
+        case JSON_NUMBER:
+        case JSON_NULL:
+            break;
+    }
+
+    return 0;
+}
+
+/**
+ * Initialize Global Silencers
+ *
+ * Initialize the silencer  for the whole netdata system.
+ *
+ * @return It returns 0 on success and -1 otherwise
+ */
+int health_initialize_global_silencers() {
+    silencers =  mallocz(sizeof(SILENCERS));
+    silencers->all_alarms=0;
+    silencers->stype=STYPE_NONE;
+    silencers->silencers=NULL;
+
+    return 0;
+}
\ No newline at end of file
diff --git a/libnetdata/health/health.h b/libnetdata/health/health.h
new file mode 100644
index 0000000000..a3dc0775fc
--- /dev/null
+++ b/libnetdata/health/health.h
@@ -0,0 +1,55 @@
+#ifndef NETDATA_HEALTH_LIB
+# define NETDATA_HEALTH_LIB 1
+
+# include "../libnetdata.h"
+
+#define HEALTH_ALARM_KEY "alarm"
+#define HEALTH_TEMPLATE_KEY "template"
+#define HEALTH_CONTEXT_KEY "context"
+#define HEALTH_CHART_KEY "chart"
+#define HEALTH_HOST_KEY "hosts"
+#define HEALTH_OS_KEY "os"
+#define HEALTH_FAMILIES_KEY "families"
+#define HEALTH_LOOKUP_KEY "lookup"
+#define HEALTH_CALC_KEY "calc"
+
+typedef struct silencer {
+    char *alarms;
+    SIMPLE_PATTERN *alarms_pattern;
+
+    char *hosts;
+    SIMPLE_PATTERN *hosts_pattern;
+
+    char *contexts;
+    SIMPLE_PATTERN *contexts_pattern;
+
+    char *charts;
+    SIMPLE_PATTERN *charts_pattern;
+
+    char *families;
+    SIMPLE_PATTERN *families_pattern;
+
+    struct silencer *next;
+} SILENCER;
+
+typedef enum silence_type {
+    STYPE_NONE,
+    STYPE_DISABLE_ALARMS,
+    STYPE_SILENCE_NOTIFICATIONS
+} SILENCE_TYPE;
+
+typedef struct silencers {
+    int all_alarms;
+    SILENCE_TYPE stype;
+    SILENCER *silencers;
+} SILENCERS;
+
+SILENCERS *silencers;
+
+extern SILENCER *create_silencer(void);
+extern int health_silencers_json_read_callback(JSON_ENTRY *e);
+extern void health_silencers_add(SILENCER *silencer);
+extern SILENCER * health_silencers_addparam(SILENCER *silencer, char *key, char *value);
+extern int health_initialize_global_silencers();
+
+#endif
diff --git a/libnetdata/json/Makefile.am b/libnetdata/json/Makefile.am
new file mode 100644
index 0000000000..1cb69ed99a
--- /dev/null
+++ b/libnetdata/json/Makefile.am
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+
+dist_noinst_DATA = \
+	README.md \
+	$(NULL)
diff --git a/libnetdata/json/README.md b/libnetdata/json/README.md
new file mode 100644
index 0000000000..fd6cb0f319
--- /dev/null
+++ b/libnetdata/json/README.md
@@ -0,0 +1,5 @@
+# json
+
+`json` contains a parser for json strings, based on `jsmn` (https://github.com/zserge/jsmn), but case you have installed the JSON-C library, the installation script will prefer it, you can also force its use with `--enable-jsonc` in the compilation time.
+
+[![analytics](https://www.google-analytics.com/collect?v=1&aip=1&t=pageview&_s=1&ds=github&dr=https%3A%2F%2Fgithub.com%2Fnetdata%2Fnetdata&dl=https%3A%2F%2Fmy-netdata.io%2Fgithub%2Flibnetdata%2Fjson%2FREADME&_u=MAC~&cid=5792dfd7-8dc4-476b-af31-da2fdb9f93d2&tid=UA-64295674-3)]()
diff --git a/libnetdata/json/jsmn.c b/libnetdata/json/jsmn.c
new file mode 100644
index 0000000000..c8d9e73db9
--- /dev/null
+++ b/libnetdata/json/jsmn.c
@@ -0,0 +1,326 @@
+#include <stdlib.h>
+
+#include "jsmn.h"
+
+/**
+ * Alloc token
+ *
+ * Allocates a fresh unused token from the token pull.
+ *
+ * @param parser the controller
+ * @param tokens the tokens I am working
+ * @param num_tokens the number total of tokens.
+ *
+ * @return it returns the next token to work.
+ */
+static jsmntok_t *jsmn_alloc_token(jsmn_parser *parser,
+                                   jsmntok_t *tokens, size_t num_tokens) {
+    jsmntok_t *tok;
+    if (parser->toknext >= num_tokens) {
+        return NULL;
+    }
+    tok = &tokens[parser->toknext++];
+    tok->start = tok->end = -1;
+    tok->size = 0;
+#ifdef JSMN_PARENT_LINKS
+    tok->parent = -1;
+#endif
+    return tok;
+}
+
+/**
+ * Fill Token
+ *
+ * Fills token type and boundaries.
+ *
+ * @param token the structure to set the values
+ * @param type is the token type
+ * @param start is the first position of the value
+ * @param end is the end of the value
+ */
+static void jsmn_fill_token(jsmntok_t *token, jsmntype_t type,
+                            int start, int end) {
+    token->type = type;
+    token->start = start;
+    token->end = end;
+    token->size = 0;
+}
+
+/**
+ * Parse primitive
+ *
+ * Fills next available token with JSON primitive.
+ *
+ * @param parser is the control structure
+ * @param js is the json string
+ * @param type is the token type
+ */
+static jsmnerr_t jsmn_parse_primitive(jsmn_parser *parser, const char *js,
+                                      size_t len, jsmntok_t *tokens, size_t num_tokens) {
+    jsmntok_t *token;
+    int start;
+
+    start = parser->pos;
+
+    for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
+        switch (js[parser->pos]) {
+#ifndef JSMN_STRICT
+            /* In strict mode primitive must be followed by "," or "}" or "]" */
+            case ':':
+#endif
+            case '\t' : case '\r' : case '\n' : case ' ' :
+            case ','  : case ']'  : case '}' :
+                goto found;
+        }
+        if (js[parser->pos] < 32 || js[parser->pos] >= 127) {
+            parser->pos = start;
+            return JSMN_ERROR_INVAL;
+        }
+    }
+#ifdef JSMN_STRICT
+    /* In strict mode primitive must be followed by a comma/object/array */
+	parser->pos = start;
+	return JSMN_ERROR_PART;
+#endif
+
+    found:
+    if (tokens == NULL) {
+        parser->pos--;
+        return 0;
+    }
+    token = jsmn_alloc_token(parser, tokens, num_tokens);
+    if (token == NULL) {
+        parser->pos = start;
+        return JSMN_ERROR_NOMEM;
+    }
+    jsmn_fill_token(token, JSMN_PRIMITIVE, start, parser->pos);
+#ifdef JSMN_PARENT_LINKS
+    token->parent = parser->toksuper;
+#endif
+    parser->pos--;
+    return 0;
+}
+
+/**
+ * Parse string
+ *
+ * Fills next token with JSON string.
+ *
+ * @param parser is the control structure
+ * @param js is the json string
+ * @param len is the js length
+ * @param tokens is structure with the tokens mapped.
+ * @param num_tokens is the total number of tokens
+ *
+ * @return It returns 0 on success and another integer otherwise
+ */
+static jsmnerr_t jsmn_parse_string(jsmn_parser *parser, const char *js,
+                                   size_t len, jsmntok_t *tokens, size_t num_tokens) {
+    jsmntok_t *token;
+
+    int start = parser->pos;
+
+    parser->pos++;
+
+    /* Skip starting quote */
+    for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
+        char c = js[parser->pos];
+
+        /* Quote: end of string */
+        if (c == '\"') {
+            if (tokens == NULL) {
+                return 0;
+            }
+            token = jsmn_alloc_token(parser, tokens, num_tokens);
+            if (token == NULL) {
+                parser->pos = start;
+                return JSMN_ERROR_NOMEM;
+            }
+            jsmn_fill_token(token, JSMN_STRING, start+1, parser->pos);
+#ifdef JSMN_PARENT_LINKS
+            token->parent = parser->toksuper;
+#endif
+            return 0;
+        }
+
+        /* Backslash: Quoted symbol expected */
+        if (c == '\\') {
+            parser->pos++;
+            switch (js[parser->pos]) {
+                /* Allowed escaped symbols */
+                case '\"': case '/' : case '\\' : case 'b' :
+                case 'f' : case 'r' : case 'n'  : case 't' :
+                    break;
+                    /* Allows escaped symbol \uXXXX */
+                case 'u':
+                    parser->pos++;
+                    int i = 0;
+                    for(; i < 4 && js[parser->pos] != '\0'; i++) {
+                        /* If it isn't a hex character we have an error */
+                        if(!((js[parser->pos] >= 48 && js[parser->pos] <= 57) || /* 0-9 */
+                             (js[parser->pos] >= 65 && js[parser->pos] <= 70) || /* A-F */
+                             (js[parser->pos] >= 97 && js[parser->pos] <= 102))) { /* a-f */
+                            parser->pos = start;
+                            return JSMN_ERROR_INVAL;
+                        }
+                        parser->pos++;
+                    }
+                    parser->pos--;
+                    break;
+                    /* Unexpected symbol */
+                default:
+                    parser->pos = start;
+                    return JSMN_ERROR_INVAL;
+            }
+        }
+    }
+    parser->pos = start;
+    return JSMN_ERROR_PART;
+}
+
+/**
+ * JSMN Parse
+ *
+ * Parse JSON string and fill tokens.
+ *
+ * @param parser the auxiliar vector used to parser
+ * @param js the string to parse
+ * @param len the string length
+ * @param tokens the place to map the tokens
+ * @param num_tokens the number of tokens present in the tokens structure.
+ *
+ * @return It returns the number of tokens present in the string on success or a negative number otherwise
+ */
+jsmnerr_t jsmn_parse(jsmn_parser *parser, const char *js, size_t len,
+                     jsmntok_t *tokens, unsigned int num_tokens) {
+    jsmnerr_t r;
+    int i;
+    jsmntok_t *token;
+    int count = 0;
+
+    for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
+        char c;
+        jsmntype_t type;
+
+        c = js[parser->pos];
+        switch (c) {
+            case '{': case '[':
+                count++;
+                if (tokens == NULL) {
+                    break;
+                }
+                token = jsmn_alloc_token(parser, tokens, num_tokens);
+                if (token == NULL)
+                    return JSMN_ERROR_NOMEM;
+                if (parser->toksuper != -1) {
+                    tokens[parser->toksuper].size++;
+#ifdef JSMN_PARENT_LINKS
+                    token->parent = parser->toksuper;
+#endif
+                }
+                token->type = (c == '{' ? JSMN_OBJECT : JSMN_ARRAY);
+                token->start = parser->pos;
+                parser->toksuper = parser->toknext - 1;
+                break;
+            case '}': case ']':
+                if (tokens == NULL)
+                    break;
+                type = (c == '}' ? JSMN_OBJECT : JSMN_ARRAY);
+#ifdef JSMN_PARENT_LINKS
+            if (parser->toknext < 1) {
+					return JSMN_ERROR_INVAL;
+				}
+				token = &tokens[parser->toknext - 1];
+				for (;;) {
+					if (token->start != -1 && token->end == -1) {
+						if (token->type != type) {
+							return JSMN_ERROR_INVAL;
+						}
+						token->end = parser->pos + 1;
+						parser->toksuper = token->parent;
+						break;
+					}
+					if (token->parent == -1) {
+						break;
+					}
+					token = &tokens[token->parent];
+				}
+#else
+                for (i = parser->toknext - 1; i >= 0; i--) {
+                    token = &tokens[i];
+                    if (token->start != -1 && token->end == -1) {
+                        if (token->type != type) {
+                            return JSMN_ERROR_INVAL;
+                        }
+                        parser->toksuper = -1;
+                        token->end = parser->pos + 1;
+                        break;
+                    }
+                }
+                /* Error if unmatched closing bracket */
+                if (i == -1) return JSMN_ERROR_INVAL;
+                for (; i >= 0; i--) {
+                    token = &tokens[i];
+                    if (token->start != -1 && token->end == -1) {
+                        parser->toksuper = i;
+                        break;
+                    }
+                }
+#endif
+                break;
+            case '\"':
+                r = jsmn_parse_string(parser, js, len, tokens, num_tokens);
+                if (r < 0) return r;
+                count++;
+                if (parser->toksuper != -1 && tokens != NULL)
+                    tokens[parser->toksuper].size++;
+                break;
+            case '\t' : case '\r' : case '\n' : case ':' : case ',': case ' ':
+                break;
+#ifdef JSMN_STRICT
+            /* In strict mode primitives are: numbers and booleans */
+			case '-': case '0': case '1' : case '2': case '3' : case '4':
+			case '5': case '6': case '7' : case '8': case '9':
+			case 't': case 'f': case 'n' :
+#else
+                /* In non-strict mode every unquoted value is a primitive */
+            default:
+#endif
+                r = jsmn_parse_primitive(parser, js, len, tokens, num_tokens);
+                if (r < 0) return r;
+                count++;
+                if (parser->toksuper != -1 && tokens != NULL)
+                    tokens[parser->toksuper].size++;
+                break;
+
+#ifdef JSMN_STRICT
+            /* Unexpected char in strict mode */
+			default:
+				return JSMN_ERROR_INVAL;
+#endif
+        }
+    }
+
+    for (i = parser->toknext - 1; i >= 0; i--) {
+        /* Unmatched opened object or array */
+        if (tokens[i].start != -1 && tokens[i].end == -1) {
+            return JSMN_ERROR_PART;
+        }
+    }
+
+    return count;
+}
+
+/**
+ * JSMN Init
+ *
+ * Creates a new parser based over a given  buffer with an array of tokens
+ * available.
+ *
+ * @param parser is the structure with values to reset
+ */
+void jsmn_init(jsmn_parser *parser) {
+    parser->pos = 0;
+    parser->toknext = 0;
+    parser->toksuper = -1;
+}
\ No newline at end of file
diff --git a/libnetdata/json/jsmn.h b/libnetdata/json/jsmn.h
new file mode 100644
index 0000000000..beff586c66
--- /dev/null
+++ b/libnetdata/json/jsmn.h
@@ -0,0 +1,75 @@
+#ifndef __JSMN_H_
+#define __JSMN_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stddef.h>
+/**
+ * JSON type identifier. Basic types are:
+ * 	o Object
+ * 	o Array
+ * 	o String
+ * 	o Other primitive: number, boolean (true/false) or null
+ */
+typedef enum {
+    JSMN_PRIMITIVE = 0,
+    JSMN_OBJECT = 1,
+    JSMN_ARRAY = 2,
+    JSMN_STRING = 3
+} jsmntype_t;
+
+typedef enum {
+    /* Not enough tokens were provided */
+            JSMN_ERROR_NOMEM = -1,
+    /* Invalid character inside JSON string */
+            JSMN_ERROR_INVAL = -2,
+    /* The string is not a full JSON packet, more bytes expected */
+            JSMN_ERROR_PART = -3,
+} jsmnerr_t;
+
+/**
+ * JSON token description.
+ *
+ * @param		type	type (object, array, string etc.)
+ * @param		start	start position in JSON data string
+ * @param		end		end position in JSON data string
+ */
+typedef struct {
+    jsmntype_t type;
+    int start;
+    int end;
+    int size;
+#ifdef JSMN_PARENT_LINKS
+    int parent;
+#endif
+} jsmntok_t;
+
+/**
+ * JSON parser. Contains an array of token blocks available. Also stores
+ * the string being parsed now and current position in that string
+ */
+typedef struct {
+    unsigned int pos; /* offset in the JSON string */
+    unsigned int toknext; /* next token to allocate */
+    int toksuper; /* superior token node, e.g parent object or array */
+} jsmn_parser;
+
+/**
+ * Create JSON parser over an array of tokens
+ */
+void jsmn_init(jsmn_parser *parser);
+
+/**
+ * Run JSON parser. It parses a JSON data string into and array of tokens, each describing
+ * a single JSON object.
+ */
+jsmnerr_t jsmn_parse(jsmn_parser *parser, const char *js, size_t len,
+                     jsmntok_t *tokens, unsigned int num_tokens);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __JSMN_H_ */
\ No newline at end of file
diff --git a/libnetdata/json/json.c b/libnetdata/json/json.c
new file mode 100644
index 0000000000..c9ff39b056
--- /dev/null
+++ b/libnetdata/json/json.c
@@ -0,0 +1,546 @@
+#include "jsmn.h"
+#include "../libnetdata.h"
+#include "json.h"
+#include "libnetdata/libnetdata.h"
+#include "../../health/health.h"
+
+#define JSON_TOKENS 1024
+
+int json_tokens = JSON_TOKENS;
+
+/**
+ * Json Tokenise
+ *
+ * Map the string given inside tokens.
+ *
+ * @param js is the string used to create the tokens
+ * @param len is the string length
+ * @param count the number of tokens present in the string
+ *
+ * @return it returns the json parsed in tokens
+ */
+#ifdef ENABLE_JSONC
+json_object *json_tokenise(char *js) {
+    if(!js) {
+        error("JSON: json string is empty.");
+        return NULL;
+    }
+
+    json_object *token = json_tokener_parse(js);
+    if(!token) {
+        error("JSON: Invalid json string.");
+        return NULL;
+    }
+
+    return token;
+}
+#else
+jsmntok_t *json_tokenise(char *js, size_t len, size_t *count)
+{
+    int n = json_tokens;
+    if(!js || !len) {
+        error("JSON: json string is empty.");
+        return NULL;
+    }
+
+    jsmn_parser parser;
+    jsmn_init(&parser);
+
+    jsmntok_t *tokens = mallocz(sizeof(jsmntok_t) * n);
+    if(!tokens) return NULL;
+
+    int ret = jsmn_parse(&parser, js, len, tokens, n);
+    while (ret == JSMN_ERROR_NOMEM) {
+        n *= 2;
+        jsmntok_t *new = reallocz(tokens, sizeof(jsmntok_t) * n);
+        if(!new) {
+            freez(tokens);
+            return NULL;
+        }
+        tokens = new;
+        ret = jsmn_parse(&parser, js, len, tokens, n);
+    }
+
+    if (ret == JSMN_ERROR_INVAL) {
+        error("JSON: Invalid json string.");
+        freez(tokens);
+        return NULL;
+    }
+    else if (ret == JSMN_ERROR_PART) {
+        error("JSON: Truncated JSON string.");
+        freez(tokens);
+        return NULL;
+    }
+
+    if(count) *count = (size_t)ret;
+
+    if(json_tokens < n) json_tokens = n;
+    return tokens;
+}
+#endif
+
+/**
+ * Callback Print
+ *
+ * Set callback print case necesary and wrinte an information inside a buffer to write in the log.
+ *
+ * @param e a pointer for a structure that has the complete information about json structure.
+ *
+ * @return It always return 0
+ */
+int json_callback_print(JSON_ENTRY *e)
+{
+    BUFFER *wb=buffer_create(300);
+
+    buffer_sprintf(wb,"%s = ", e->name);
+    char txt[50];
+    switch(e->type) {
+        case JSON_OBJECT:
+            e->callback_function = json_callback_print;
+            buffer_strcat(wb,"OBJECT");
+            break;
+
+        case JSON_ARRAY:
+            e->callback_function = json_callback_print;
+            sprintf(txt,"ARRAY[%lu]", e->data.items);
+            buffer_strcat(wb, txt);
+            break;
+
+        case JSON_STRING:
+            buffer_strcat(wb, e->data.string);
+            break;
+
+        case JSON_NUMBER:
+            sprintf(txt,"%Lf", e->data.number);
+            buffer_strcat(wb,txt);
+
+            break;
+
+        case JSON_BOOLEAN:
+            buffer_strcat(wb, e->data.boolean?"TRUE":"FALSE");
+            break;
+
+        case JSON_NULL:
+            buffer_strcat(wb,"NULL");
+            break;
+    }
+    info("JSON: %s", buffer_tostring(wb));
+    buffer_free(wb);
+    return 0;
+}
+
+/**
+ * JSONC Set String
+ *
+ * Set the string value of the structure JSON_ENTRY.
+ *
+ * @param e the output structure
+ */
+static inline void json_jsonc_set_string(JSON_ENTRY *e,char *key,const char *value) {
+    size_t length = strlen(key);
+    e->type = JSON_STRING;
+    memcpy(e->name,key,length);
+    e->name[length] = 0x00;
+    e->data.string = (char *) value;
+}
+
+
+#ifdef ENABLE_JSONC
+/**
+ * JSONC set Boolean
+ *
+ * Set the boolean value of the structure JSON_ENTRY
+ *
+ * @param e the output structure
+ * @param value the input value
+ */
+static inline void json_jsonc_set_boolean(JSON_ENTRY *e,int value) {
+    e->type = JSON_BOOLEAN;
+    e->data.boolean = value;
+}
+
+/**
+ * Parse Array
+ *
+ * Parse the array object.
+ *
+ * @param ptr the pointer for the object that we will parse.
+ * @param callback_data additional data to be used together the callback function
+ * @param callback_function function used to create a silencer.
+ */
+static inline void json_jsonc_parse_array(json_object *ptr, void *callback_data,int (*callback_function)(struct json_entry *)) {
+    int end = json_object_array_length(ptr);
+    JSON_ENTRY e;
+
+    if(end) {
+        int i;
+        i = 0;
+
+        enum json_type type;
+        do {
+            json_object *jvalue =  json_object_array_get_idx(ptr, i);
+            if(jvalue) {
+                e.callback_data = callback_data;
+                e.type = JSON_OBJECT;
+                callback_function(&e);
+                json_object_object_foreach(jvalue, key, val) {
+                    type = json_object_get_type(val);
+                    if (type == json_type_array) {
+                        e.type = JSON_ARRAY;
+                        json_jsonc_parse_array(val, callback_data, callback_function);
+                    } else if (type == json_type_object) {
+                        json_walk(val,callback_data,callback_function);
+                    } else if (type == json_type_string) {
+                        json_jsonc_set_string(&e,key,json_object_get_string(val));
+                        callback_function(&e);
+                    } else if (type == json_type_boolean) {
+                        json_jsonc_set_boolean(&e,json_object_get_boolean(val));
+                        callback_function(&e);
+                    }
+                }
+            }
+
+        } while (++i < end);
+    }
+}
+#else
+
+/**
+ * Walk string
+ *
+ * Set JSON_ENTRY to string and map the values from jsmntok_t.
+ *
+ * @param js the original string
+ * @param t the tokens
+ * @param start the first position
+ * @param e the output structure.
+ *
+ * @return It always return 1
+ */
+size_t json_walk_string(char *js, jsmntok_t *t, size_t start, JSON_ENTRY *e)
+{
+    char old = js[t[start].end];
+    js[t[start].end] = '\0';
+    e->original_string = &js[t[start].start]