[core] Adding toggle for CORS, GZIP in admin/cms configuration (#30)

This PR enables admins to disable/enable CORS and GZIP from within the admin CMS configuration page. Both are enabled by default.

Note: currently, the GZIP implementation is 100% on the fly, for every qualifying API endpoint request. This could add significant CPU usage, but dramatically decreases bandwidth. Will be considering other better implementations, but for now YMMV.

Possible optimizations:
- pooling gzip Writers vs. creating a new one for each response
- caching gzipped responses (in memory? on disk?) 
- enforcing size threshold (only gzip content larger than N bytes) 

1 files changed, 18 insertions, 2 deletions

diff --git a/system/admin/config/config.go b/system/admin/config/config.go
index 7b57dc0..0d55700 100644
--- a/system/admin/config/config.go
+++ b/system/admin/config/config.go
@@ -16,6 +16,8 @@ type Config struct {
 	AdminEmail      string   `json:"admin_email"`
 	ClientSecret    string   `json:"client_secret"`
 	Etag            string   `json:"etag"`
+	DisableCORS     bool     `json:"cors_disabled"`
+	DisableGZIP     bool     `json:"gzip_disabled"`
 	CacheInvalidate []string `json:"cache"`
 }
 
@@ -49,7 +51,7 @@ func (c *Config) MarshalEditor() ([]byte, error) {
 		},
 		editor.Field{
 			View: editor.Input("AdminEmail", c, map[string]string{
-				"label": "Adminstrator Email (will be notified of internal system information)",
+				"label": "Adminstrator Email (notified of internal system information)",
 			}),
 		},
 		editor.Field{
@@ -65,7 +67,7 @@ func (c *Config) MarshalEditor() ([]byte, error) {
 		},
 		editor.Field{
 			View: editor.Input("Etag", c, map[string]string{
-				"label":    "Etag Header (used for static asset cache)",
+				"label":    "Etag Header (used to cache resources)",
 				"disabled": "true",
 			}),
 		},
@@ -75,6 +77,20 @@ func (c *Config) MarshalEditor() ([]byte, error) {
 			}),
 		},
 		editor.Field{
+			View: editor.Checkbox("DisableCORS", c, map[string]string{
+				"label": "Disable CORS (so only " + c.Domain + " can fetch your data)",
+			}, map[string]string{
+				"true": "Disable CORS",
+			}),
+		},
+		editor.Field{
+			View: editor.Checkbox("DisableGZIP", c, map[string]string{
+				"label": "Disable GZIP (will increase server speed, but also bandwidth)",
+			}, map[string]string{
+				"true": "Disable GZIP",
+			}),
+		},
+		editor.Field{
 			View: editor.Checkbox("CacheInvalidate", c, map[string]string{
 				"label": "Invalidate cache on save",
 			}, map[string]string{