AhmedELShafaie · October 20, 2020 23:49 · Jun 21, 2018
diff --git a/wordpress_com_nginx_proxy_to_subpath.md b/wordpress_com_nginx_proxy_to_subpath.md
@@ -0,0 +1,53 @@
+Let's say we can a blog hosted as Wordpress.com but visible on our custom domain in subpath due to SEO.
+WordPress.com supports changing domain/subdomain but not path.
+
+We could either make our own installation, change hosting provier or make nginx proxy with URL rewrites.
+
+- WP blog: https://example.wordpress.com/
+- Desired site: http://example.com/blog/
+
+This tutorial is inpsired by http://marsbard.github.io/2016-07-30-replace-urls-behind-nginx-reverse-proxy/.
+
+Nginx needs the [ngx_http_sub_module](https://nginx.org/en/docs/http/ngx_http_sub_module.html).
+You can check with: `nginx -V`.
+
+`nginx.conf` - put into the `server` section and restart:
+
+```
+# nginx rule to make a wordpress.com site visible at subpath of our domain.
+# Wordpress.com allows setting domain/subdomain, but not custom path.
+# We have to proxy requests and rewrite base URLs rendered by WP to our site.
+# Original base URL: https://example.wordpress.com/
+# User facing base URL: https://example.com/blog/
+# For administration better use the original domain.
+
+# path on our site (visible to users)
+location /blog/ {
+  # request get proxied to this site (hosted by wordpress.com)
+  proxy_pass https://example.wordpress.com/;
+  proxy_set_header X-Forwarded-Host $host;
+  proxy_set_header X-Forwarded-Proto $scheme;
+  # disable compression to make substitution work
+  proxy_set_header Accept-Encoding "";
+
+  # substitute URL rendered by wordpress.com to our location
+  # http://marsbard.github.io/2016-07-30-replace-urls-behind-nginx-reverse-proxy/
+  # plain URL:
+  sub_filter 'https://example.wordpress.com' '$scheme://$host/blog';
+  # escaped in JS:
+  sub_filter 'https:\/\/example.wordpress.com' '$scheme:\/\/$host\/blog';
+  # redirect in JS in URL parameters:
+  sub_filter 'redirect_to=https%3A%2F%2Fexample.wordpress.com%2F' 'redirect_to=$scheme%3A%2F%2F$host%2Fblog%2F';
+  # replace many times
+  sub_filter_once off;
+  # keep the last modified header
+  sub_filter_last_modified on;
+}
+```
+
+Various places where base URL appears in plain or escaped forms:
+```
+https://example.wordpress.com
+https:\/\/example.wordpress.com
+https:\/\/example.wordpress.com\/wp-login.php?redirect_to=https%3A%2F%2Fexample.wordpress.com%2F
+```