Add another backlogged post from the "TIL" section

Really LNIL (Last Night I Learned)

_posts/2021-02-16-async-h1-error-tide.md

@@ -0,0 +1,54 @@
+---
+layout: post
+title: Reverse proxying a Tide application with Nginx
+tags:
+- nginx
+- rust
+---
+
+Every now and again I'll encounter a silly problem, fix it, forget about it,
+and then later run into the _exact_ same problem again. Today's example is a
+confusing error I encountered when reverse-proxying a
+[Tide](https://github.com/http-rs/tide) application with
+[Nginx](https://nginx.org). In the Tide application, I was greeted with an ever-so-descriptive error:
+
+```
+ERROR tide::listener::tcp_listener > async-h1 error
+```
+
+I *knew* that I had hit this before, because I
+remember discussing with [jbr](https://github.com/jbr) the need for
+[async-h1](https://github.com/http-rs/async-h1) to be a bit more verbose in its
+error messages. Try as I might however, I was not able to remember how to solve
+the problem  Looking at the Nginx error logs, which weren't that much more helpful:
+
+```
+2021/02/14 17:41:26 [error] 45774#101333: *53 upstream prematurely closed connection while reading response header from upstream, client: 192.168.1.1, server: dotdotvote.com, request: "GET / HTTP/1.1", upstream: "http://10.0.1.6:8000/", host: "dotdotvote.com"
+2021/02/14 17:41:26 [error] 45774#101333: *53 upstream prematurely closed connection while reading response header from upstream, client: 192.168.1.1, server: dotdotvote.com, request: "GET /favicon.ico HTTP/1.1", upstream: "http://10.0.1.6:8000/favicon.ico", host: "dotdotvote.com", referrer: "https://dotdotvote.com/"
+```
+
+
+
+Eventually I stumbled into [this closed GitHub
+issue](https://github.com/http-rs/tide/issues/458) which had the critical
+missing configuration snippet I was missing: `proxy_http_version 1.1;` It seems
+that the `async-h1` crate cannot parse HTTP 1.0, or 2.0, or some version of
+HTTP other than 1.1. I'm honestly not really sure what format was being sent
+along to the Tide application.
+
+My full `location` block below for reference: 
+```
+  location / {
+    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    proxy_set_header Host            $host;
+    proxy_set_header X-Real-IP       $remote_addr;
+    # https://github.com/http-rs/tide/issues/458#issuecomment-619243201
+    proxy_http_version 1.1;
+
+    proxy_pass http://dotdotvote;
+  }
+```
+
+
+With that one weird trick, Nginx is happily reverse-proxying my little Tide
+application!