Remove netdatacli response size limitation (#14906)

* Dump config

* Add charcat and rawcat

* Build incoming response in an buffer

* Allocate a buffer to hold the command response so that we dont have a 4K char limit

* Add a dumpconfig command to output the current netdata.conf

* Remove -W dumpconfig for now

* Fix typo

* Improve help message

cli/cli.c

@@ -10,9 +10,6 @@ static uv_shutdown_t shutdown_req;
 static char command_string[MAX_COMMAND_LENGTH];
 static unsigned command_string_size;
 
-static char response_string[MAX_COMMAND_LENGTH];
-static unsigned response_string_size;
-
 static int exit_status;
 
 struct command_context {
@@ -24,8 +21,10 @@ struct command_context {
     cmd_status_t status;
 };
 
-static void parse_command_reply(void)
+static void parse_command_reply(BUFFER *buf)
 {
+    char *response_string = (char *) buffer_tostring(buf);
+    unsigned response_string_size = buffer_strlen(buf);
     FILE *stream = NULL;
     char *pos;
     int syntax_error = 0;
@@ -64,28 +63,21 @@ static void parse_command_reply(void)
 
 static void pipe_read_cb(uv_stream_t *client, ssize_t nread, const uv_buf_t *buf)
 {
-    if (0 == nread) {
+    BUFFER  *response = client->data;
+
+    if (0 == nread)
         fprintf(stderr, "%s: Zero bytes read by command pipe.\n", __func__);
-    } else if (UV_EOF == nread) {
-//      fprintf(stderr, "EOF found in command pipe.\n");
-        parse_command_reply();
-    } else if (nread < 0) {
-        fprintf(stderr, "%s: %s\n", __func__, uv_strerror(nread));
+    else if (UV_EOF == nread)
+       parse_command_reply(response);
+    else if (nread < 0) {
+       fprintf(stderr, "%s: %s\n", __func__, uv_strerror(nread));
+       (void)uv_read_stop((uv_stream_t *)client);
     }
+    else
+        buffer_fast_rawcat(response, buf->base, nread);
 
-    if (nread < 0) { /* stop stream due to EOF or error */
-        (void)uv_read_stop((uv_stream_t *)client);
-    } else if (nread) {
-        size_t to_copy;
-
-        to_copy = MIN((unsigned int) nread, MAX_COMMAND_LENGTH - 1 - response_string_size);
-        memcpy(response_string + response_string_size, buf->base, to_copy);
-        response_string_size += to_copy;
-        response_string[response_string_size] = '\0';
-    }
-    if (buf && buf->len) {
+    if (buf && buf->len)
         free(buf->base);
-    }
 }
 
 static void alloc_cb(uv_handle_t *handle, size_t suggested_size, uv_buf_t *buf)
@@ -104,8 +96,7 @@ static void shutdown_cb(uv_shutdown_t* req, int status)
     (void)status;
 
     /* receive reply */
-    response_string_size = 0;
-    response_string[0] = '\0';
+    client_pipe.data = req->data;
 
     ret = uv_read_start((uv_stream_t *)&client_pipe, alloc_cb, pipe_read_cb);
     if (ret) {
@@ -113,16 +104,17 @@ static void shutdown_cb(uv_shutdown_t* req, int status)
         uv_close((uv_handle_t *)&client_pipe, NULL);
         return;
     }
-
 }
 
 static void pipe_write_cb(uv_write_t* req, int status)
 {
     int ret;
 
-    (void)req;
     (void)status;
 
+    uv_pipe_t *clientp = req->data;
+    shutdown_req.data = clientp->data;
+
     ret = uv_shutdown(&shutdown_req, (uv_stream_t *)&client_pipe, shutdown_cb);
     if (ret) {
         fprintf(stderr, "uv_shutdown(): %s\n", uv_strerror(ret));
@@ -144,10 +136,11 @@ static void connect_cb(uv_connect_t* req, int status)
         exit(-1);
     }
     if (0 == command_string_size) {
-        s = fgets(command_string, MAX_COMMAND_LENGTH, stdin);
+        s = fgets(command_string, MAX_COMMAND_LENGTH - 1, stdin);
     }
     (void)s; /* We don't need input to communicate with the server */
     command_string_size = strlen(command_string);
+    client_pipe.data = req->data;
 
     write_req.data = &client_pipe;
     write_buf.base = command_string;
@@ -191,11 +184,13 @@ int main(int argc, char **argv)
         }
     }
 
+    req.data = buffer_create(128, NULL);
     uv_pipe_connect(&req, &client_pipe, PIPENAME, connect_cb);
 
     uv_run(loop, UV_RUN_DEFAULT);
 
     uv_close((uv_handle_t *)&client_pipe, NULL);
+    buffer_free(client_pipe.data);
 
     return exit_status;
 }

daemon/commands.c

@@ -47,6 +47,7 @@ static cmd_status_t cmd_write_config_execute(char *args, char **message);
 static cmd_status_t cmd_ping_execute(char *args, char **message);
 static cmd_status_t cmd_aclk_state(char *args, char **message);
 static cmd_status_t cmd_version(char *args, char **message);
+static cmd_status_t cmd_dumpconfig(char *args, char **message);
 
 static command_info_t command_info_array[] = {
         {"help", cmd_help_execute, CMD_TYPE_HIGH_PRIORITY},                  // show help menu
@@ -61,7 +62,8 @@ static command_info_t command_info_array[] = {
         {"write-config", cmd_write_config_execute, CMD_TYPE_ORTHOGONAL},
         {"ping", cmd_ping_execute, CMD_TYPE_ORTHOGONAL},
         {"aclk-state", cmd_aclk_state, CMD_TYPE_ORTHOGONAL},
-        {"version", cmd_version, CMD_TYPE_ORTHOGONAL}
+        {"version", cmd_version, CMD_TYPE_ORTHOGONAL},
+        {"dumpconfig", cmd_dumpconfig, CMD_TYPE_ORTHOGONAL}
 };
 
 /* Mutexes for commands of type CMD_TYPE_ORTHOGONAL */
@@ -127,6 +129,8 @@ static cmd_status_t cmd_help_execute(char *args, char **message)
              "    Return with 'pong' if agent is alive.\n"
              "aclk-state [json]\n"
              "    Returns current state of ACLK and Cloud connection. (optionally in json).\n"
+             "dumpconfig\n"
+             "    Returns the current netdata.conf on stdout.\n"
              "version\n"
              "    Returns the netdata version.\n",
              MAX_COMMAND_LENGTH - 1);
@@ -330,6 +334,17 @@ static cmd_status_t cmd_version(char *args, char **message)
     return CMD_STATUS_SUCCESS;
 }
 
+static cmd_status_t cmd_dumpconfig(char *args, char **message)
+{
+    (void)args;
+
+    BUFFER *wb = buffer_create(1024, NULL);
+    config_generate(wb, 0);
+    *message = strdupz(buffer_tostring(wb));
+    buffer_free(wb);
+    return CMD_STATUS_SUCCESS;
+}
+
 static void cmd_lock_exclusive(unsigned index)
 {
     (void)index;
@@ -393,32 +408,30 @@ static void pipe_write_cb(uv_write_t* req, int status)
 
     uv_close((uv_handle_t *)client, pipe_close_cb);
     --clients;
-    freez(client->data);
+    buffer_free(client->data);
     info("Command Clients = %u\n", clients);
 }
 
-static inline void add_char_to_command_reply(char *reply_string, unsigned *reply_string_size, char character)
+static inline void add_char_to_command_reply(BUFFER *reply_string, unsigned *reply_string_size, char character)
 {
-    reply_string[(*reply_string_size)++] = character;
+    buffer_fast_charcat(reply_string, character);
+    *reply_string_size +=1;
 }
 
-static inline void add_string_to_command_reply(char *reply_string, unsigned *reply_string_size, char *str)
+static inline void add_string_to_command_reply(BUFFER *reply_string, unsigned *reply_string_size, char *str)
 {
     unsigned len;
 
     len = strlen(str);
-
-    if (MAX_COMMAND_LENGTH - 1 < len + *reply_string_size)
-        len = MAX_COMMAND_LENGTH - *reply_string_size - 1;
-
-    strncpyz(reply_string + *reply_string_size, str, len);
+    buffer_fast_strcat(reply_string, str, len);
     *reply_string_size += len;
 }
 
 static void send_command_reply(struct command_context *cmd_ctx, cmd_status_t status, char *message)
 {
     int ret;
-    char *reply_string = mallocz(MAX_COMMAND_LENGTH);
+    BUFFER *reply_string = buffer_create(128, NULL);
+
     char exit_status_string[MAX_EXIT_STATUS_LENGTH + 1] = {'\0', };
     unsigned reply_string_size = 0;
     uv_buf_t write_buf;
@@ -436,13 +449,12 @@ static void send_command_reply(struct command_context *cmd_ctx, cmd_status_t sta
 
     cmd_ctx->write_req.data = client;
     client->data = reply_string;
-    write_buf.base = reply_string;
+    write_buf.base = reply_string->buffer;
     write_buf.len = reply_string_size;
     ret = uv_write(&cmd_ctx->write_req, (uv_stream_t *)client, &write_buf, 1, pipe_write_cb);
     if (ret) {
         error("uv_write(): %s", uv_strerror(ret));
     }
-    info("COMMAND: Sending reply: \"%s\"", reply_string);
 }
 
 cmd_status_t execute_command(cmd_t idx, char *args, char **message)

daemon/commands.h

@@ -26,6 +26,7 @@ typedef enum cmd {
     CMD_PING,
     CMD_ACLK_STATE,
     CMD_VERSION,
+    CMD_DUMPCONFIG,
     CMD_TOTAL_COMMANDS
 } cmd_t;
 

libnetdata/buffer/buffer.h

@@ -152,6 +152,35 @@ static inline void _buffer_json_depth_pop(BUFFER *wb) {
     wb->json.depth--;
 }
 
+static inline void buffer_fast_charcat(BUFFER *wb, const char c) {
+
+    buffer_need_bytes(wb, 2);
+    *(&wb->buffer[wb->len]) = c;
+    wb->len += 1;
+    wb->buffer[wb->len] = '\0';
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_fast_rawcat(BUFFER *wb, const char *txt, size_t len) {
+    if(unlikely(!txt || !*txt || !len)) return;
+
+    buffer_need_bytes(wb, len + 1);
+
+    const char *t = txt;
+    const char *e = &txt[len];
+
+    char *d = &wb->buffer[wb->len];
+
+    while(t != e)
+        *d++ = *t++;
+
+    wb->len += len;
+    wb->buffer[wb->len] = '\0';
+
+    buffer_overflow_check(wb);
+}
+
 static inline void buffer_fast_strcat(BUFFER *wb, const char *txt, size_t len) {
     if(unlikely(!txt || !*txt || !len)) return;