gotosocial/docs/installation_guide/apache-httpd.md

# Reverse proxy with Apache HTTP Server

## Requirements

For this you will need the Apache HTTP Server.

That is a fairly popular package so your distro will probably have it.

### Ubuntu

```bash
sudo apt install apache2
```

### Arch

```bash
sudo pacman -S apache
```

### OpenSuse

```bash
sudo zypper install apache2
```

### Install modules

You'll also need to install additional modules for Apache HTTP Server. You can do that with the following command:

```bash
sudo a2enmod proxy_http md ssl headers rewrite
```

## Configure GoToSocial

We're going to have Apache handle LetsEncrypt certificates, so you need to turn off built-in LetsEncrypt support in your GoToSocial config.

First open the file in your text editor:

```bash
sudoedit /gotosocial/config.yaml
```

Then set `letsencrypt-enabled: false`.

If the reverse proxy will be running on the same machine, set the `bind-address` to `"localhost"` so that the GoToSocial server is only accessible via loopback. Otherwise it may be possible to bypass your proxy by connecting to GoToSocial directly, which might be undesirable.

If GoToSocial is already running, restart it.

```bash
sudo systemctl restart gotosocial.service
```

Or if you don't have a systemd service just restart it manually.

## Set up Apache HTTP Server with SSL managed using MD module

Now we'll configure Apache HTTP Server to serve GoToSocial requests.

First we'll write a configuration for Apache HTTP Server and put it in `/etc/apache2/sites-available`:

```bash
sudo mkdir -p /etc/apache2/sites-available/
sudoedit /etc/apache2/sites-available/example.com.conf
```

In the above `sudoedit` command, replace `example.com` with the hostname of your GoToSocial server.

The file you're about to create should look a bit like this:

```apache
MDomain example.com auto
MDCertificateAgreement accepted

<VirtualHost *:80 >
  ServerName example.com
</VirtualHost>

<VirtualHost *:443>
  ServerName example.com

  RewriteEngine On
  RewriteCond %{HTTP:Upgrade} websocket [NC]
  RewriteCond %{HTTP:Connection} upgrade [NC]
  # set to 127.0.0.1 instead of localhost to work around https://stackoverflow.com/a/52550758
  RewriteRule ^/?(.*) "ws://127.0.0.1:8080/$1" [P,L]

  SSLEngine On
  ProxyPreserveHost On
  # set to 127.0.0.1 instead of localhost to work around https://stackoverflow.com/a/52550758
  ProxyPass / http://127.0.0.1:8080/
  ProxyPassReverse / http://127.0.0.1:8080/

  RequestHeader set "X-Forwarded-Proto" expr=https
</VirtualHost>
```

Again, replace occurrences of `example.com` in the above config file with the hostname of your GtS server. If your domain name is `gotosocial.example.com`, then `gotosocial.example.com` would be the correct value.

You should also change `http://127.0.0.1:8080` to the correct address and port (if it's not on `127.0.0.1:8080`) of your GtS server. For example, if you're running GoToSocial on another machine with the local ip of `192.168.178.69` and on port `8080` then `http://192.168.178.69:8080/` would be the correct value.

`Rewrite*` directives are needed to ensure that Websocket streaming connections also work. See the [websocket](./websocket.md) document for more information on this.

`ProxyPreserveHost On` is essential: It guarantees that the proxy and the GoToSocial speak of the same Server name. If not, GoToSocial will build the wrong authentication headers, and all attempts at federation will be rejected with 401 Unauthorized.

By default, apache sets `X-Forwarded-For` in forwarded requests. To make this and rate limiting work, set the `trusted-proxies` configuration variable. See the [rate limiting](../api/ratelimiting.md) and [general configuration](../configuration/general.md) docs

Save and close the config file.

Now we'll need to link the file we just created to the folder that Apache HTTP Server reads configurations for active sites from.

```bash
sudo mkdir /etc/apache2/sites-enabled
sudo ln -s /etc/apache2/sites-available/example.com.conf /etc/apache2/sites-enabled/
```

In the above `ln` command, replace `example.com` with the hostname of your GoToSocial server.

Now check for configuration errors.

```bash
sudo apachectl -t
```

If everything is fine you should get this as output:

```text
Syntax OK
```

Everything working? Great! Then restart Apache HTTP Server to load your new config file.

```bash
sudo systemctl restart apache2
```

Now, monitor the logs to see when the new LetsEncrypt certificate arrives (`tail -F /var/log/apache2/error.log`), and then reload Apache one last time with the above `systemctl restart` command. After that you should be good to go!

Apache HTTP Server needs to be restart (or reloaded), every time `mod_md` gets a new certificate; see the module's docs for [more information](https://github.com/icing/mod_md#how-to-manage-server-reloads).

Depending on your version of Apache HTTP Server, you may see the following error: `error (specific information not available): acme problem urn:ietf:params:acme:error:invalidEmail: Error creating new account :: contact email "webmaster@localhost" has invalid domain : Domain name needs at least one dot`

If this happens, you'll need to do one (or all) of the below:

1. Update `/etc/apache2/sites-enabled/000-default.conf` and change the `ServerAdmin` value to a valid email address (then reload Apache HTTP Server).
2. Add the line `MDContactEmail your.email.address@whatever.com` below the `MDomain` line in `/etc/apache2/sites-available/example.com.conf`, replacing `your.email.address@whatever.com` with a valid email address, and `example.com` with your GtS host name.

## Set up Apache HTTP Server with SSL managed manually or by an external software (e.g. Certbot or acme.sh)

If you prefer to have a manual setup or setting SSL using a different service to manage it (Certbot, etc), then you can use a simpler setup for your Apache HTTP Server.

First we'll write a configuration for Apache HTTP Server and put it in `/etc/apache2/sites-available`:

```bash
sudo mkdir -p /etc/apache2/sites-available/
sudoedit /etc/apache2/sites-available/example.com.conf
```

In the above `sudoedit` command, replace `example.com` with the hostname of your GoToSocial server.

The file you're about to create should look initially for both 80 (required) and 443 ports (optional) a bit like this:

```apache
<VirtualHost *:80>
  ServerName example.com

  RewriteEngine On
  RewriteCond %{HTTP:Upgrade} websocket [NC]
  RewriteCond %{HTTP:Connection} upgrade [NC]
  # set to 127.0.0.1 instead of localhost to work around https://stackoverflow.com/a/52550758
  RewriteRule ^/?(.*) "ws://127.0.0.1:8080/$1" [P,L]

  ProxyPreserveHost On
  # set to 127.0.0.1 instead of localhost to work around https://stackoverflow.com/a/52550758
  ProxyPass / http://127.0.0.1:8080/
  ProxyPassReverse / http://127.0.0.1:8080/

</VirtualHost>
```

Again, replace occurrences of `example.com` in the above config file with the hostname of your GtS server. If your domain name is `gotosocial.example.com`, then `gotosocial.example.com` would be the correct value.

You should also change `http://127.0.0.1:8080` to the correct address and port (if it's not on `127.0.0.1:8080`) of your GtS server. For example, if you're running GoToSocial on another machine with the local ip of `192.168.178.69` and on port `8080` then `http://192.168.178.69:8080/` would be the correct value.

`Rewrite*` directives are needed to ensure that Websocket streaming connections also work. See the [websocket](./websocket.md) document for more information on this.

`ProxyPreserveHost On` is essential: It guarantees that the proxy and the GoToSocial speak of the same Server name. If not, GoToSocial will build the wrong authentication headers, and all attempts at federation will be rejected with 401 Unauthorized.

In the case of providing an initial setup for the 443 port looking for additional managing by an external tool, you could use default certificates provided by the server which you can find referenced in the `default-ssl.conf` file at `/etc/apache2/sites-available/`.

Save and close the config file.

Now we'll need to link the file we just created to the folder that Apache HTTP Server reads configurations for active sites from.

```bash
sudo mkdir /etc/apache2/sites-enabled
sudo ln -s /etc/apache2/sites-available/example.com.conf /etc/apache2/sites-enabled/
```

In the above `ln` command, replace `example.com` with the hostname of your GoToSocial server.

Now check for configuration errors.

```bash
sudo apachectl -t
```

If everything is fine you should get this as output:

```text
Syntax OK
```

Everything working? Great! Then restart Apache HTTP Server to load your new config file.

```bash
sudo systemctl restart apache2
```

## Troubleshooting

If you cannot connect to the site in your browser, the reverse proxy setup doesn't work. Compare the Apache log file (`tail -F /var/log/apache2/access.log`) with the GoToSocial log file. Requests made must show up in both places. Double check the `ProxyPass` setting.

If you can connect but your posts don't federate and your account cannot be found from elsewhere, check your logs. Federation is broken if you see messages attempting to read your profile (something like `level=INFO … method=GET statusCode=401 path=/users/your_username msg="Unauthorized: …"`) or post to your inbox (something like `level=INFO … method=POST statusCode=404 path=/your_username/inbox msg="Not Found: …"`). Double check the `ProxyPreserveHost` setting.

If you can connect but you cannot authorize your account in a Mastodon client app, check your headers. Use `curl -I https://example.com` and look for the `Content-Security-Policy` header. If your webserver sets it, you might have to unset it. One way to do that is to use `Header unset Content-Security-Policy` in the Apache site config file (something like `example.com.conf`).