Phoenix routing challenges with a subfolder deployment

[joshisa]

I'm trying to setup asciinema under a url with a subfolder of https://x.x.x.x/asciinema . I've been able to find and patch most of the rails portions to allow the home page, all of the non-phoenix links and the player to function normally.

Unfortunately, I'm facing 500 error codes with my "x.x.x.x/asciinema/docs" and my login links. I suspect that i need to make some adjustments within my /lib/asciinema_web/router.ex and maybe my nginx file ... but my debug efforts so far haven't pointed me in the right direction.

I've enabled error_log within the nginx "sites-enabled/default" file. The traffic for "/asciinema/docs" seems to be matching to the phoenix server. Here's a snip:

2018/02/22 21:16:59 [debug] 1903#1903: *766 http script var: "/docs"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http script copy: "/index.html"
2018/02/22 21:16:59 [debug] 1903#1903: *766 trying to use file: "/docs/index.html" "/app/public/docs/index.html"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http script var: "/docs"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http script copy: ".html"
2018/02/22 21:16:59 [debug] 1903#1903: *766 trying to use file: "/docs.html" "/app/public/docs.html"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http script var: "/docs"
2018/02/22 21:16:59 [debug] 1903#1903: *766 trying to use file: "/docs" "/app/public/docs"
2018/02/22 21:16:59 [debug] 1903#1903: *766 trying to use file: "@phoenix" "/app/public@phoenix"
2018/02/22 21:16:59 [debug] 1903#1903: *766 test location: "@phoenix"
2018/02/22 21:16:59 [debug] 1903#1903: *766 using location: @phoenix "/docs?"
2018/02/22 21:16:59 [debug] 1903#1903: *766 rewrite phase: 3
2018/02/22 21:16:59 [debug] 1903#1903: *766 post rewrite phase: 4
2018/02/22 21:16:59 [debug] 1903#1903: *766 generic phase: 5
2018/02/22 21:16:59 [debug] 1903#1903: *766 generic phase: 6
2018/02/22 21:16:59 [debug] 1903#1903: *766 generic phase: 7
2018/02/22 21:16:59 [debug] 1903#1903: *766 access phase: 8
2018/02/22 21:16:59 [debug] 1903#1903: *766 access phase: 9
2018/02/22 21:16:59 [debug] 1903#1903: *766 access phase: 10
2018/02/22 21:16:59 [debug] 1903#1903: *766 post access phase: 11
2018/02/22 21:16:59 [debug] 1903#1903: *766 try files phase: 12
2018/02/22 21:16:59 [debug] 1903#1903: *766 http init upstream, client timer: 0
2018/02/22 21:16:59 [debug] 1903#1903: *766 epoll add event: fd:3 op:3 ev:80002005
2018/02/22 21:16:59 [debug] 1903#1903: *766 http map started
2018/02/22 21:16:59 [debug] 1903#1903: *766 http script var: "https"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http map: "https" "https"

After the headers are rewritten per the nginx /etc/nginx/sites-enabled/default file - sample below:

upstream rails-server {
    server 127.0.0.1:3000 fail_timeout=0;
}

upstream phoenix-server {
    server 127.0.0.1:4000 fail_timeout=0;
}

proxy_cache_path /cache levels=1:2 keys_zone=png_cache:10m max_size=10g
                 inactive=14d use_temp_path=off;

map $http_x_forwarded_proto $real_scheme {
    default $http_x_forwarded_proto;
    ''      $scheme;
}

server {
    listen 80 default_server;
    listen [::]:80 default_server;

    server_name _;

    root /app/public;
    error_log /app/public/nginx_error.log debug;

    client_max_body_size 16m;

    location ~ ^/(phoenix/|css/|js/|images/|fonts/|docs/?|api/asciicasts|connect/|login/?|users/?|user(/edit)?$|session/?|a/[^/]+/iframe) {
        try_files /maintenance.html $uri/index.html $uri.html $uri @phoenix;
    }

    location ~ ^/a/[^.]+\.png$ {
        proxy_cache png_cache;
        proxy_cache_revalidate on;
        proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
        proxy_cache_lock on;
        proxy_cache_key $uri;
        proxy_ignore_headers Set-Cookie;

        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 $real_scheme;
        proxy_set_header Host $http_host;
        proxy_pass http://phoenix-server;
        proxy_redirect off;
    }

    location ~ ^/a/[^.]+\.(js|json|cast|gif)$ {
        try_files $uri $uri/index.html $uri.html @phoenix;
    }

    location / {
        try_files $uri $uri/index.html $uri.html @rails;
    }

    location ~ "^/assets/.+-[0-9a-f]{32,}" {
        gzip_static on;
        expires 1y;
        add_header Cache-Control public;

        add_header ETag "";
        break;
    }

    location @rails {
        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 $real_scheme;
        proxy_set_header Host $http_host;
        proxy_pass http://rails-server;
        proxy_redirect off;
        error_page 500 502 504 /500.html; # Rails error pages
    }

    location @phoenix {
        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 $real_scheme;
        proxy_set_header Host $http_host;
        proxy_pass http://phoenix-server;
        proxy_redirect off;
    }
}

Failing Request --> 500 Reponse

2018/02/22 21:16:59 [debug] 1903#1903: *766 http proxy header:
"GET /docs HTTP/1.0
X-Real-IP: z.z.z.z
X-Forwarded-For: x.x.x.x, y.y.y.y
X-Forwarded-Proto: https
Host: x.x.x.x
Connection: close
X-Forwarded-Host: x.x.x.x
X-Forwarded-Port: 443
X-Original-URI: /asciinema/docs
X-Scheme: https
upgrade-insecure-requests: 1
user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.167 Safari/537.36
accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
dnt: 1
accept-encoding: gzip, deflate, br

2018/02/22 21:16:59 [debug] 1903#1903: *766 http run request: "/docs?"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http upstream check client, write event:1, "/docs"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http upstream recv(): -1 (11: Resource temporarily unavailable)
2018/02/22 21:16:59 [debug] 1903#1903: *766 delete posted event 000055A82B6B6500
2018/02/22 21:16:59 [debug] 1903#1903: *766 http upstream request: "/docs?"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http upstream send request handler
[....]
2018/02/22 21:16:59 [debug] 1903#1903: *766 http upstream request: "/docs?"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http upstream process header
2018/02/22 21:16:59 [debug] 1903#1903: *766 malloc: 000055A82B625660:4096
2018/02/22 21:16:59 [debug] 1903#1903: *766 recv: fd:9 272 of 4096
2018/02/22 21:16:59 [debug] 1903#1903: *766 http proxy status 500 "500 Internal Server Error"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http proxy header: "server: Cowboy"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http proxy header: "date: Thu, 22 Feb 2018 21:16:59 GMT"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http proxy header: "content-length: 21"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http proxy header: "content-type: text/html; charset=utf-8"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http proxy header: "cache-control: max-age=0, private, must-revalidate"
2018/02/22 21:16:59 [debug] 1903#1903: *766 http proxy header: "x-request-id: 602707ndgqqmmvmudiqob1vnc2r8v7jg"

Would welcome any hints/guidance. Absolutely love this project!

[ku1ik]

The rest of the codebase was ported to Elixir this year, so there's no dual-stack anymore, which should make what you want to achieve easier. It's been a while since you tried setting this up, so I'm not sure if you're still interested in it. I'll close this one, but feel free to re-open and we'll figure it out.

[lyknode]

Hi @sickill,

I'm having the same use case as @joshisa. I'm trying to run asciinema-server on http://localhost/asciinema but static files (and websocket?) keep getting served on the root path.

I've had a couple attempt at fixing this but having no knowlegde of erlang or elixir, that task has proven to be difficult.

My configuration is:

config :asciinema, AsciinemaWeb.Endpoint,
  url: [
    scheme: "http",
    host: "localhost",
    path: "/asciinema",
    port: "80"
  ]

And the fix I tried was:

--- a/lib/asciinema_web/endpoint.ex
+++ b/lib/asciinema_web/endpoint.ex
@@ -14,12 +14,15 @@ defmodule AsciinemaWeb.Endpoint do
   socket "/socket", AsciinemaWeb.UserSocket,
     websocket: true
 
+  config = Application.get_env(:asciinema, __MODULE__)
+  url = Keyword.get(config, :url)
+
   # Serve at "/" the static files from "priv/static" directory.
   #
   # You should set gzip to true if you are running phx.digest
   # when deploying your static files in production.
   plug Plug.Static,
-    at: "/",
+    at: url[:path],
     from: :asciinema,
     gzip: true,
     only: ~w(css fonts images js favicon.ico robots.txt)

I tried a couple of variant without any success at compiling.

Any help would be much appreciated.