api: Add option to output graphs as base64 (#8535)

* Allow 'option' param in graph endpoint

* Update lint and update docs

* Uncomment api response

* Add imagedestroy on 'tobias_trim' section

* Add base64 to port endpoints also

doc/API/Devices.md

@@ -396,6 +396,7 @@ Input:
   - to: This is the date you would like the graph to end - See http://oss.oetiker.ch/rrdtool/doc/rrdgraph.en.html for more information.
   - width: The graph width, defaults to 1075.
   - height: The graph height, defaults to 300.
+  - output: Set how the graph should be outputted (base64, display), defaults to display.
 
 Example:
 ```curl

html/includes/api_functions.inc.php

@@ -140,6 +140,7 @@ function get_graph_by_port_hostname()
     $vars         = array();
     $vars['port'] = urldecode($router['ifname']);
     $vars['type'] = $router['type'] ?: 'port_bits';
+    $vars['output'] = $_GET['output'] ?: 'display';
     if (!empty($_GET['from'])) {
         $vars['from'] = $_GET['from'];
     }
@@ -164,6 +165,9 @@ function get_graph_by_port_hostname()
     rrdtool_initialize(false);
     include 'includes/graphs/graph.inc.php';
     rrdtool_close();
+    if ($vars['output'] === 'base64') {
+        api_success(['image' => $base64_output, 'content-type' => get_image_type()], 'image');
+    }
 }
 
 
@@ -212,6 +216,7 @@ function get_graph_generic_by_hostname()
     $sensor_id    = $router['sensor_id'] ?: null;
     $vars         = array();
     $vars['type'] = $router['type'] ?: 'device_uptime';
+    $vars['output'] = $_GET['output'] ?: 'display';
     if (isset($sensor_id)) {
         $vars['id']   = $sensor_id;
         if (str_contains($vars['type'], '_wireless')) {
@@ -244,6 +249,10 @@ function get_graph_generic_by_hostname()
     rrdtool_initialize(false);
     include 'includes/graphs/graph.inc.php';
     rrdtool_close();
+
+    if ($vars['output'] === 'base64') {
+        api_success(['image' => $base64_output, 'content-type' => get_image_type()], 'image');
+    }
 }
 
 
@@ -628,6 +637,7 @@ function get_graph_by_portgroup()
     $group  = $router['group'] ?: '';
     $id     = $router['id'] ?: '';
     $vars   = array();
+    $vars['output'] = $_GET['output'] ?: 'display';
     if (!empty($_GET['from'])) {
         $vars['from'] = $_GET['from'];
     }
@@ -662,6 +672,9 @@ function get_graph_by_portgroup()
     rrdtool_initialize(false);
     include 'includes/graphs/graph.inc.php';
     rrdtool_close();
+    if ($vars['output'] === 'base64') {
+        api_success(['image' => $base64_output, 'content-type' => get_image_type()], 'image');
+    }
 }
 
 

html/includes/graphs/graph.inc.php

@@ -19,7 +19,7 @@ $height   = $vars['height'];
 $title    = $vars['title'];
 $vertical = $vars['vertical'];
 $legend   = $vars['legend'];
-
+$output   = (!empty($vars['output']) ? $vars['output'] : 'default');
 $from = (isset($vars['from']) ? $vars['from'] : time() - 60 * 60 * 24);
 $to   = (isset($vars['to']) ? $vars['to'] : time());
 
@@ -28,7 +28,7 @@ if ($from < 0) {
 }
 
 $period = ($to - $from);
-
+$base64_output = '';
 $prev_from = ($from - $period);
 
 $graphfile = $config['temp_dir'].'/'.strgen();
@@ -132,7 +132,6 @@ if ($error_msg) {
         if ($rrd_options) {
             rrdtool_graph($graphfile, $rrd_options);
             d_echo($rrd_cmd);
-
             if (is_file($graphfile)) {
                 if (!$debug) {
                     set_image_type();
@@ -157,12 +156,32 @@ if ($error_msg) {
                         $trans_colour = imagecolorallocatealpha($dst_im, 0, 0, 0, 127);
                         imagefill($dst_im, 0, 0, $trans_colour);
                         imagecopy($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h);
-                        imagepng($dst_im);
-                        imagedestroy($dst_im);
+                        if ($output === 'base64') {
+                            ob_start();
+                                imagepng($png);
+                                $imagedata = ob_get_contents();
+                                imagedestroy($png);
+                            ob_end_clean();
+                            
+                            $base64_output = base64_encode($imagedata);
+                        } else {
+                            imagepng($dst_im);
+                            imagedestroy($dst_im);
+                        }
                     } else {
-                        $fd = fopen($graphfile, 'r');
-                        fpassthru($fd);
-                        fclose($fd);
+                        if ($output === 'base64') {
+                            $fd = fopen($graphfile, 'r');
+                            ob_start();
+                                fpassthru($fd);
+                                $imagedata = ob_get_contents();
+                                fclose($fd);
+                            ob_end_clean();
+                            $base64_output =  base64_encode($imagedata);
+                        } else {
+                            $fd = fopen($graphfile, 'r');
+                            fpassthru($fd);
+                            fclose($fd);
+                        }
                     }
                 } else {
                     echo `ls -l $graphfile`;