client: initial og:title and og:image for posts

client/metatags.lua

@@ -22,7 +22,13 @@ end
 
 -- Add the site name tag
 add_meta_tag("og:site_name", server_info.config.name)
-add_meta_tag("og:url", ngx.var.scheme .. "://" .. ngx.var.http_host .. ngx.var.request_uri)
+add_meta_tag("og:url", ngx.var.external_host_url .. ngx.var.request_uri)
+
+if ngx.var.request_uri_path:match('^/post') then
+  local post_info = cjson.decode((ngx.location.capture("/_internal_api"..ngx.var.request_uri_path)).body)
+  add_meta_tag("og:image", ngx.var.external_host_url .. '/' .. post_info.contentUrl)
+  add_meta_tag("og:title", server_info.config.name .. " - Post " .. post_info.id)
+end
 
 local final_response = page_html.body:gsub("{{ generated_head_tags }}", additional_tags)
 

client/nginx.conf.docker

@@ -25,9 +25,12 @@ http {
         server __BACKEND__:6666;
     }
 
+    map $request_uri $request_uri_path {
+        "~^(?P<path>[^?]*)(\?.*)?$"  $path;
+    }
+
     init_by_lua_block {
         cjson = require("cjson")
-        -- gumbo = require("gumbo")
     }
 
     server {
@@ -107,6 +110,7 @@ http {
         location /_meta_tags_html {
             internal;
             root /var/www;
+            set $external_host_url "${scheme}://${http_host}";
             content_by_lua_file /etc/nginx/metatags.lua;
         }