new post on reverse proxy websocket

_posts/2024-02-29-reverse-proxy-jupyter-on-sub-path.md

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+---
+layout: post
+title: "How to Reverse Proxy Jupyter Notebook on a Subpath Using Nginx"
+categories: linux
+date: 2024-02-29
+---
+
+Recently, I needed to proxy my Jupyter Notebook web interface from `host.domain:8888` to a subpath directly from the HTTP 80 port `host.domain/jupyter/`. Unfortunately, the fact that Jupyter uses WebSocket for the communication between its kernel and the web application, makes setting up correct proxy in Nginx slightly more complicated. After a few searches and experimentation, I have reached a working solution, which I am documenting below.
+
+#### In `jupyter_notebook_config.py` file
+In order for the Jupyter server to serve files correctly, we need to set its base URL in `$HOME/.jupyter/jupyter_notebook_config.py`. Simply set or add the following line
+``` python
+c.ServerApp.base_url = '/jupyter/'
+```
+
+#### In `http` section of `nginx.conf` file
+We need to create a variable based on the `$http_upgrade` value
+``` apacheconf
+map $http_upgrade $connection_upgrade {
+    default upgrade;
+    '' close;
+}
+```
+
+#### In `server` section of `nginx.conf` file
+We need to define a subpath and use the variable we just defined
+``` apacheconf
+location /jupyter/ {
+        proxy_pass http://localhost:8888;
+        proxy_http_version 1.1;
+        proxy_set_header Host $http_host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+	proxy_set_header Connection $connection_upgrade;
+	proxy_set_header Upgrade $http_upgrade;
+}
+```