Running lando start in this repo should result in a warning from Lando that "the service 'nginx' is not running!"
lando logs -s nginx reveals that the proxy_pass directive in lando/nginx.conf is to blame:
nginx_1 | INFO ==> ** Starting NGINX setup **
nginx_1 | INFO ==> Validating settings in NGINX_* env vars...
nginx_1 | INFO ==> Initializing NGINX...
nginx_1 | DEBUG ==> Custom configuration detected. Using it...
nginx_1 |
nginx_1 | INFO ==> ** NGINX setup finished! **
nginx_1 | INFO ==> ** Starting NGINX **
nginx_1 | 2020/05/29 21:29:28 [emerg] 176#0: host not found in upstream "appserver.clojureapp.internal" in /opt/bitnami/nginx/conf/nginx.conf:17
nginx_1 | nginx: [emerg] host not found in upstream "appserver.clojureapp.internal" in /opt/bitnami/nginx/conf/nginx.conf:17
This seems to be an issue with the way the different service hosts detect (or rather fail to detect) each other.
For example, if I remove dbhost and appserver's dependency on it from the Landofile, the reverse proxy works:
$ git checkout remove-dbhost
$ lando rebuild -y
$ curl http://clojure-app.lndo.site
Hello, Lando!
Alternatively, if I remove the proxy_pass directive so that Nginx starts up correctly (git checkout remove-proxy), Nginx even sees the internal host as expected:
$ git checkout remove-proxy
$ lando rebuild -y
$ curl http://clojure-app.lndo.site
Nginx is working!
$ lando ssh -s nginx -c 'curl appserver.clojureapp.internal:8080'
Hello, Lando!
For these reasons, I don't think this is an issue with my application/config but rather with the underlying Docker network as created by Lando.