Add privacyPolicyURL (CMD_PRIVACY_POLICY_URL)

If you use Google OAuth, you need to add Privacy Policy to the top.
https://support.google.com/cloud/answer/9110914#all-apps-zippy
https://github.com/hackmdio/codimd/issues/1582#issuecomment-682270394

Signed-off-by: Tamotsu Takahashi <ttakah@gmail.com>

app.js

@@ -194,6 +194,7 @@ app.set('view engine', 'ejs')
 app.locals.useCDN = config.useCDN
 app.locals.serverURL = config.serverURL
 app.locals.sourceURL = config.sourceURL
+app.locals.privacyPolicyURL = config.privacyPolicyURL
 app.locals.allowAnonymous = config.allowAnonymous
 app.locals.allowAnonymousEdits = config.allowAnonymousEdits
 app.locals.permission = config.permission

lib/config/default.js

@@ -37,6 +37,7 @@ module.exports = {
   defaultPermission: 'editable',
   dbURL: '',
   db: {},
+  privacyPolicyURL: '',
   // ssl path
   sslKeyPath: '',
   sslCertPath: '',

lib/config/environment.js

@@ -35,6 +35,7 @@ module.exports = {
   sessionSecret: process.env.CMD_SESSION_SECRET,
   sessionLife: toIntegerConfig(process.env.CMD_SESSION_LIFE),
   responseMaxLag: toIntegerConfig(process.env.CMD_RESPONSE_MAX_LAG),
+  privacyPolicyURL: process.env.CMD_PRIVACY_POLICY_URL,
   imageUploadType: process.env.CMD_IMAGE_UPLOAD_TYPE,
   imgur: {
     clientID: process.env.CMD_IMGUR_CLIENTID

public/views/index/body.ejs

@@ -156,6 +156,7 @@
                     <h6 class="social-foot">
                         <%- __('Follow us on %s and %s.', '<a href="https://github.com/hackmdio/CodiMD" target="_blank" rel="noopener"><i class="fa fa-github"></i> GitHub</a>, <a href="https://gitter.im/hackmdio/hackmd" target="_blank" rel="noopener"><i class="fa fa-comments"></i> Gitter</a>', '<a href="https://poeditor.com/join/project/q0nuPWyztp" target="_blank" rel="noopener"><i class="fa fa-globe"></i> POEditor</a>') %>
                     </h6>
+                    <% if(privacyPolicyURL && privacyPolicyURL.length > 0) { %><p><a href="<%- privacyPolicyURL %>"><%= __('Privacy Policy') %></a></p><% } %>
                 </div>
             </div>
         </div>