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Simple nginx config

Hello all!

I finally got my Lemmy instance up and running yay!

It runs on a local machine, I have nginx installed and my website pointing onto it.

lemmy.mindoki.com => my_static_ip(port 80) => local_ip => nginx

In ngunx I just set up a hello world message, and it works out. lemmy.mindoki.com shows it.

Now, my Lemmy instance is accessible on 0.0.0.0:1236 but obviously only from inside the hosting machine itself.

I have tinkered a bit with the nginx.conf but I feel there is lot of things to do wrongly, especially as it's 'dynamic', but also it seems like a schoolbook example (for Lemmy, so no hits on my favourite search engine), so maybe someone has a working nginx.conf file to spare for a basic setup like this?

Thanks a bunch!

19 comments

Max_P

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Not sure if that's what you're looking for, but the Ansible repository has an NGINX template for both the Docker internal routing as well as for the host to reach the Docker internal one.

It is indeed pretty basic: essentially you just need to proxy_pass a location to the correct backend server.

Valmond

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Thanks a bunch, but that is still quite incomprehensible for me, which means that either I'll just fool around trying to get it right (which is not what I want to do) or learn it all the hard way (which I try to escape :-) ) or get some clever help ^^

Should I change: default "http://lemmy-ui"; "~^(?!(GET|HEAD)).*:" "http://lemmy"; proxy_pass "http://lemmy"; to my website somehow (I have an A redirect from lemmy.mindoki.com to my external IP => route to the linux box)?

Thanks again!

Max_P

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So, the part that selects what hostname it serves is the server_name directive. What those http://lemmy and http://lemmy-ui point to is the backend services. In this case, it's assuming the Docker setup where the containers are named lemmy and lemmy-ui respectively. They're completely invisible to the user, and in this case relies on Docker directing those names to the appropriate containers automatically. You don't need to change those, unless you're not using Docker. If you're not using Docker, then those need to point to the address to reach lemmy and lemmy-ui. So for example, you might want to set that to http://127.0.0.1:1236.

Essentially, traffic comes in at port 80/443 or whatever your listen directives say, then NGINX receives the connection and processes the host header in the request to match it against which server{} block serves that server_name, or falls back to whichever server block defines listen ..... default_server, or if there isn't any, it usually falls into whichever server block happens to be first loaded in by the server. Pretty much only the listen and server_name directives are relevant here in terms of handling incoming traffic from the outside, mostly. Things like ssl_* will also configure how to handle incoming HTTPS connection, but that happens slightly after the server block has been identified using the listen and server_name directives. Most other directives are about how to handle the request once it's in the server block.

Then, it processes the request entirely within that server block. In this particular case, there's a bit of logic so that it proxies it to lemmy-ui unless it's an ActivityPub request or anything not a GET/HEAD request, in which case it tries to proxy it to the lemmy backend service. That's what the if directives accomplish here. Usually we put those in location blocks, in this case the location / block so it handles all paths except other location blocks that override it. Some directives can be put directly in the server block and will apply to all locations unless overridden. Technically NGINX processes the location blocks first in order of precision (ie. /foo/bar/42/comments is more specific than /foo, and when there's a tie it's based on configuration order in the config file).

There's also a location block to map some URLs like /.well-known and /pictrs that also gets proxied to the lemmy backend directly. The way those work is say, you want to handle something at http://example.com/demo, you can add a location /demo {} block and the directives in that block will only apply when the URL is /demo/*.

Does that clarify things for you?

Valmond

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Thank you and yes, yes it does clarify a lot how nginx is working!

I'm trying to use use the conf file coming with lemmy docker install, and after some searching I don't even know if this is deprecated or not (it's in the http{} ), or how I should tell nginx the information about where to find the docker devices:

upstream lemmy {
    # this needs to map to the lemmy (server) docker service hostname
    server "lemmy:8536";
}
upstream lemmy-ui {
    # this needs to map to the lemmy-ui docker service hostname
    server "lemmy-ui:1234";
}

Also, shouldn't I tell nginx to listen to port 80?

Also, I get this error when I run "sudo nginx -s reload" and I don't even understand what it means:

nginx: [emerg] host not found in upstream "lemmy" in /etc/nginx/nginx.conf:53

Thank you again, I'm a slow learner!

Max_P

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There's two NGINX servers in the Docker setup: one on the inside, and one on the outside/on the host.

If you run NGINX from the host or outside of the docker-compose, lemmy and lemmy-ui won't resolve because that only exists within Docker. It does a bit of magic that essentially amounts to putting these in the containers' /etc/hosts and maps to the internal IPs that the containers get. Docker has some sort of virtual router built-in, each compose gets its own virtual network and everything.

If you use the Docker setup, you can use the configs I linked from the Ansible repo essentially as-is with minor tweaks. The internal NGINX config can be kept completely unchanged, and the outside one only needs minor tweaks to set up your own hostname and the port for the internal one. You only need to fill in the {{domain}} and {{lemmy_port}} placeholders in the outside one. The example outside NGINX config already listens to both 80 and 443.

Basically with the suggested setup, you go Internet -> your server (port 80/443) -> the internal NGINX in Docker (port 1236) -> lemmy/lemmy-ui.

Valmond

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Good morning and thank you, I'll use your recommended config asap, and then be back with more questions most probably :-) !

Valmond

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Hello !

I followed your instructions, taking the:

lemmy-ansible/templates/nginx_internal.conf

and sticking:

lemmy-ansible/templates/nginx.conf

in the "http {" section + changing all the {{domain}} to lemmy.mindoki.com and changing the {{lemmy_port}} to 1236 (FYI: 0.0.0.0:1236 hits up Lemmy locally)

Saving it all off in the nginx nginx.conf file.

I feel exceedingly stupid, but is this the way to go? Because I get this error when I reload nginx:

nginx: [emerg] host not found in upstream "lemmy:8536" in /etc/nginx/nginx.conf:111

Cheers and thanks again!

Edit: removing the upstreams, changed the backend proxy_pass, but to no avail...

Max_P

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Can you describe your setup in more details? Are you using the Docker setup with also NGINX running on the host outside of Docker?

If so, nginx_internal.conf must be passed in as a volume to the inner NGINX via the docker-compose. On the host, you only need the bits from nginx.conf. Don't try to use the internal ones, it doesn't make sense.

If you post your configs it will be easier to pinpoint exactly what's wrong. Also paste the output of docker ps.

Valmond

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I'm off one week on holidays, will sure post all config when I come back, thanks again!

Valmond

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Hello, I'm back with more questions and clarifications!

This is what I did to install Lemmy:

Install a fresh Linux Mint on an old PC.

Follow the 'official' docker install: https://join-lemmy.org/docs/administration/install_docker.html

I continued with nginx, lets encrypt etc.

I also installed PosgreSQL and added a user Lemmy.

I forward a TCP connection from my fix public IP to the lemmy PC and pointed lemmy.mindoki.com with an A redirection onto that public IP:PORT.

The only 'exotic' thing done was that I added these lines to /home/fediverse/.bashrc :

export LEMMY_CONFIG_LOCATION="/media/fediverse/Storage/lemmy/lemmy.hjson"

EMMY_DATABASE_URL="postgres://lemmy:redacted_password@localhost:5432/lemmy"

. "$HOME/.cargo/env"

I don't think (but not completely sure) that the last line was added by me manually.

Now I can access Lemmy locally on localhost:1236 and everything works (inscription, creations of 'subs' etc).

I added the nginx.conf config file at the end of this message (some lines are commented out to make it work at all).

Almost feels like I should have a very much shorter nginx config file 🙃

Thanks again!

Cheers

EDIT: I messed something up, the server now only answers "Server error", I'll be back later ...

phoenix591

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you tell it what you mean by lemmy and lemmy-ui earlier in the config file outside of the server {} block

upstream lemmy {
# this needs to map to the lemmy (server) docker service hostname
server "127.0.0.1:8536";
}
upstream lemmy-ui {
# this needs to map to the lemmy-ui docker service hostname
server "127.0.0.1:1234";
}