varnishstat: Add json output and continous mode

bin/varnishstat/varnishstat.c

@@ -82,6 +82,69 @@ do_xml(struct VSM_data *vd)
 	printf("</varnishstat>\n");
 }
 
+
+/*--------------------------------------------------------------------*/
+
+static int
+do_json_cb(void *priv, const struct VSC_point * const pt)
+{
+	uint64_t val;
+	int *jp;
+	char jsonkey[255];
+	char jsontmp[255];
+
+	jp = priv;
+
+	assert(!strcmp(pt->fmt, "uint64_t"));
+	val = *(const volatile uint64_t*)pt->ptr;
+
+	if (*jp) *jp = 0; else printf(",\n");
+	jsonkey[0] = '\0';
+
+	/* build the JSON key name.  */
+	if (strcmp(pt->ident, "")  && strcmp(pt->class, ""))  sprintf(jsonkey, "%s.%s", pt->class, pt->ident);
+	if (strcmp(pt->ident, "")  && !strcmp(pt->class, "")) sprintf(jsonkey, "%s", pt->ident);
+	if (!strcmp(pt->ident, "") && strcmp(pt->class, ""))  sprintf(jsonkey, "%s", pt->class);
+
+	strcpy(jsontmp, jsonkey);
+	if (strcmp(jsonkey, "")) sprintf(jsonkey, "%s.%s", jsontmp, pt->name);
+	else strcpy(jsonkey, pt->name);
+
+	printf("\t\"%s\": {", jsonkey);
+
+	if (strcmp(pt->class, "")) printf("\"type\": \"%s\", ",  pt->class);
+	if (strcmp(pt->ident, "")) printf("\"ident\": \"%s\", ", pt->ident);
+
+	printf("\"value\": %ju, ", val);
+
+	printf("\"flag\": \"%c\", ", pt->flag);
+	printf("\"description\": \"%s\"", pt->desc);
+	printf("}");
+
+	if (*jp) printf("\n");
+	return (0);
+}
+
+static void
+do_json(struct VSM_data *vd)
+{
+	char time_stamp[20];
+	time_t now;
+	int jp;
+
+	jp = 1;
+
+	printf("{\n");
+	now = time(NULL);
+
+	(void)strftime(time_stamp, 20, "%Y-%m-%dT%H:%M:%S", localtime(&now));
+	printf("\t\"timestamp\": \"%s\",\n", time_stamp);
+	(void)VSC_Iter(vd, do_json_cb, &jp);
+	printf("\n}\n");
+	fflush(stdout);
+}
+
+
 /*--------------------------------------------------------------------*/
 
 struct once_priv {
@@ -167,7 +230,7 @@ usage(void)
 	    "[-1lV] [-f field_list] "
 	    VSC_n_USAGE " "
 	    "[-w delay]\n");
-	fprintf(stderr, FMT, "-1", "Print the statistics once and exit");
+	fprintf(stderr, FMT, "-1", "Print the statistics to stdout.");
 	fprintf(stderr, FMT, "-f field_list",
 	    "Comma separated list of fields to display. ");
 	fprintf(stderr, FMT, "",
@@ -178,9 +241,11 @@ usage(void)
 	    "The varnishd instance to get logs from");
 	fprintf(stderr, FMT, "-V", "Display the version number and exit");
 	fprintf(stderr, FMT, "-w delay",
-	    "Wait delay seconds between updates.  The default is 1.");
+	    "Wait delay seconds between updates.  Default is 1 second. Can also be be used with -1, -x or -j for repeated output.");
 	fprintf(stderr, FMT, "-x",
-	    "Print statistics once as XML and exit.");
+	    "Print statistics to stdout as XML.");
+	fprintf(stderr, FMT, "-j",
+	    "Print statistics to stdout as JSON.");
 #undef FMT
 	exit(1);
 }
@@ -191,12 +256,12 @@ main(int argc, char * const *argv)
 	int c;
 	struct VSM_data *vd;
 	const struct VSC_C_main *VSC_C_main;
-	int delay = 1, once = 0, xml = 0;
+	int delay = 1, once = 0, xml = 0, json = 0, do_repeat = 0;
 
 	vd = VSM_New();
 	VSC_Setup(vd);
 
-	while ((c = getopt(argc, argv, VSC_ARGS "1f:lVw:x")) != -1) {
+	while ((c = getopt(argc, argv, VSC_ARGS "1f:lVw:xjt:")) != -1) {
 		switch (c) {
 		case '1':
 			once = 1;
@@ -210,11 +275,15 @@ main(int argc, char * const *argv)
 			VCS_Message("varnishstat");
 			exit(0);
 		case 'w':
+			do_repeat = 1;
 			delay = atoi(optarg);
 			break;
 		case 'x':
 			xml = 1;
 			break;
+		case 'j':
+			json = 1;
+			break;
 		default:
 			if (VSC_Arg(vd, c, optarg) > 0)
 				break;
@@ -227,12 +296,27 @@ main(int argc, char * const *argv)
 
 	VSC_C_main = VSC_Main(vd);
 
-	if (xml)
-		do_xml(vd);
-	else if (once)
-		do_once(vd, VSC_C_main);
-	else
+	if (!(xml || json || once)) {
 		do_curses(vd, VSC_C_main, delay);
+		exit(0);
+	}
+
+	while (1) {
+		if (xml)
+			do_xml(vd);
+		else if (json)
+			do_json(vd);
+		else if (once)
+			do_once(vd, VSC_C_main);
+		else {
+			assert(0);
+		}
+		if (!do_repeat) break;
+
+		// end of output block marker.
+		printf("\n");
 
+		sleep(delay);
+	} 
 	exit(0);
 }

doc/sphinx/reference/varnishstat.rst

@@ -10,15 +10,16 @@ Varnish Cache statistics
 
 :Author: Dag-Erling Smørgrav
 :Author: Per Buer
-:Date:   2010-06-1
-:Version: 1.0
+:Author: Lasse Karstensen
+:Date:   2011-11-07
+:Version: 1.1
 :Manual section: 1
 
 
 SYNOPSIS
 ========
 
-varnishstat [-1] [-x] [-f field_list] [-l] [-n varnish_name] [-V] [-w delay]
+varnishstat [-1] [-x] [-j] [-f field_list] [-l] [-n varnish_name] [-V] [-w delay]
 
 DESCRIPTION
 ===========
@@ -27,7 +28,7 @@ The varnishstat utility displays statistics from a running varnishd(1) instance.
 
 The following options are available:
 
--1          Instead of presenting of a continuously updated display, print the statistics once and exit.
+-1          Instead of presenting of a continuously updated display, print the statistics to stdout.
 
 -f          A comma separated list of the fields to display.  If it starts with '^' it is used as an exclusion
 	    list.
@@ -39,9 +40,11 @@ The following options are available:
 
 -V          Display the version number and exit.
 
--w delay    Wait delay seconds between updates.  The default is 1.
+-w delay    Wait delay seconds between updates.  The default is 1. Can also be used with -1, -x or -j for repeated output.
 
--x          Displays the result as XML once.
+-x          Displays the result as XML.
+
+-j          Displays the result as JSON.
 
 The columns in the main display are, from left to right:
 
@@ -65,6 +68,29 @@ When using the -x option, the output is::
     <description>FIELD DESCRIPTION</description> 
   </stat> 
 
+With -j the output format is::
+
+  {
+    "timestamp": "YYYY-MM-DDTHH:mm:SS",
+    "client_conn": {
+	"value": 0, "flag": "a", 
+	"description": "Client connections accepted"
+    },
+    "client_drop": {
+	"value": 0, "flag": "a", 
+	"description": "Connection dropped, no sess/wrk"
+    },
+    "LCK.backend.creat": {
+	"type": "LCK", "ident": "backend", "value": 1, 
+	"flag": "a", "description": "Created locks"
+    },
+    [..]
+  }
+
+Timestamp is the time when the report was generated by varnishstat.
+
+Repeated output with -1, -x or -j will have a single empty line (\\n) between each block of output.
+
 
 SEE ALSO
 ========
@@ -91,4 +117,4 @@ This document is licensed under the same licence as Varnish
 itself. See LICENCE for details.
 
 * Copyright (c) 2006 Verdens Gang AS
-* Copyright (c) 2006-2008 Varnish Software AS
+* Copyright (c) 2006-2011 Varnish Software AS