Add switch for insecure TLS

application/forms/Config/BackendForm.php

@@ -45,6 +45,14 @@ class BackendForm extends ConfigForm
                     'label'             => $this->translate('Graphite Web password'),
                     'description'       => $this->translate('The above user\'s password')
                 ]
+            ],
+            [
+                'checkbox',
+                'graphite_insecure',
+                [
+                    'label'         => $this->translate('Connect insecurely'),
+                    'description'   => $this->translate('Check this to not verify the remote\'s TLS certificate')
+                ]
             ]
         ]);
     }

library/Graphite/Graphing/GraphingTrait.php

@@ -69,6 +69,7 @@ trait GraphingTrait
                 (new GraphiteWebClient(Url::fromPath($graphite->url)))
                     ->setUser($graphite->user)
                     ->setPassword($graphite->password)
+                    ->setInsecure($graphite->insecure)
             );
         }
 

library/Graphite/Graphing/GraphiteWebClient.php

@@ -33,6 +33,13 @@ class GraphiteWebClient
      */
     protected $password;
 
+    /**
+     * Don't verify the remote's TLS certificate
+     *
+     * @var bool
+     */
+    protected $insecure = false;
+
     /**
      * HTTP client
      *
@@ -74,7 +81,12 @@ class GraphiteWebClient
             ->getAbsoluteUrl();
 
         // TODO(ak): keep connections alive (TCP handshakes are a bit expensive and TLS handshakes are very expensive)
-        return (string) $this->httpClient->send(new Request($method, $url, $headers, $body))->getBody();
+        return (string) $this->httpClient->send(
+            new Request($method, $url, $headers, $body),
+            ['curl' => [
+                CURLOPT_SSL_VERIFYPEER => ! $this->insecure
+            ]]
+        )->getBody();
     }
 
     /**
@@ -148,4 +160,28 @@ class GraphiteWebClient
 
         return $this;
     }
+
+    /**
+     * Get whether not to verify the remote's TLS certificate
+     *
+     * @return bool
+     */
+    public function getInsecure()
+    {
+        return $this->insecure;
+    }
+
+    /**
+     * Set whether not to verify the remote's TLS certificate
+     *
+     * @param bool $insecure
+     *
+     * @return $this
+     */
+    public function setInsecure($insecure = true)
+    {
+        $this->insecure = $insecure;
+
+        return $this;
+    }
 }