Add documentation for nginx

1 files changed, 131 insertions, 5 deletions

diff --git a/doc/book/src/cookbook/reverse_proxy.md b/doc/book/src/cookbook/reverse_proxy.md
index b4674852..14633ae8 100644
--- a/doc/book/src/cookbook/reverse_proxy.md
+++ b/doc/book/src/cookbook/reverse_proxy.md
@@ -1,19 +1,142 @@
 # Configuring a reverse proxy
 
+The main reason to add a reverse proxy in front of Garage is to provide TLS to your users.
+
+In production you will likely need your certificates signed by a certificate authority.
+The most automated way is to use a provider supporting the [ACME protocol](https://datatracker.ietf.org/doc/html/rfc8555) 
+such as [Let's Encrypt](https://letsencrypt.org/), [ZeroSSL](https://zerossl.com/) or [Buypass Go SSL](https://www.buypass.com/ssl/products/acme).
+
+If you are only testing Garage, you can generate a self-signed certificate to follow the documentation:
+
+```bash
+openssl req \
+    -new \
+    -x509 \
+    -keyout /tmp/garage.key \
+    -out /tmp/garage.crt \
+    -nodes  \
+    -subj "/C=XX/ST=XX/L=XX/O=XX/OU=XX/CN=localhost/emailAddress=X@X.XX" \
+    -addext "subjectAltName = DNS:localhost, IP:127.0.0.1"
+
+cat /tmp/garage.key /tmp/garage.crt > /tmp/garage.pem
+```
+
+Be careful as you will need to allow self signed certificates in your client.
+For example, with minio, you must add the `--insecure` flag.
+An example:
+
+```bash
+mc ls --insecure garage/
+```
+
+## socat (only for testing purposes)
+
+If you want to test Garage with a TLS frontend, socat can do it for you in a single command:
+
+```bash
+socat \
+"openssl-listen:443,\
+reuseaddr,\
+fork,\
+verify=0,\
+cert=/tmp/garage.pem" \
+tcp4-connect:localhost:3900
+```
+
 ## Nginx
 
+Nginx is a well-known reverse proxy suitable for production.
+We do the configuration in 3 steps: first we define the upstream blocks ("the backends")
+then we define the server blocks ("the frontends") for the S3 endpoint and finally for the web endpoint.
+
+The following configuration blocks can be all put in the same `/etc/nginx/sites-available/garage.conf`.
+To make your configuration active, run `ln -s /etc/nginx/sites-available/garage.conf /etc/nginx/sites-enabled/`.
+If you directly put the instructions in the root `nginx.conf`, keep in mind that these configurations must be enclosed inside a `http { }` block.
+
+And do not forget to reload nginx with `systemctl reload nginx` or `nginx -s reload`.
+
+### Defining backends
+
+First, we need to tell to nginx how to access our Garage cluster.
+Because we have multiple nodes, we want to leverage all of them by spreading the load.
+
+In nginx, we can do that with the upstream directive.
+Because we have 2 endpoints: one for the S3 API and one to serve websites,
+we create 2 backends named respectively `s3_backend` and `web_backend`.
+
+A documented example for the `s3_backend` assuming you chose port 3900:
+
+```nginx
+upstream s3_backend {
+  # if you have a garage instance locally
+  server 127.0.0.1:3900;
+  # you can also put your other instances
+  server 192.168.1.3:3900;
+  # domain names also work
+  server garage1.example.com:3900;
+  # you can assign weights if you have some servers 
+  # that are more powerful than others
+  server garage2.example.com:3900 weight=2;
+}
+```
+
+A similar example for the `web_backend` assuming you chose port 3902:
+
+```nginx
+upstream web_backend {
+  server 127.0.0.1:3902;
+  server 192.168.1.3:3902;
+  server garage1.example.com:3902;
+  server garage2.example.com:3902 weight=2;
+}
+```
+
+### Exposing the S3 API
+
+The configuration section for the S3 API is simple as we only support path-access style yet.
+We simply configure the TLS parameters and forward all the requests to the backend:
+
 ```nginx
 server {
-  # In production you should use TLS instead of plain HTTP
-  listen [::]:80;
+  listen [::]:443 http2 ssl;
+  ssl_certificate     /tmp/garage.crt;
+  ssl_certificate_key /tmp/garage.key;
+
+  # should be the endpoint you want
+  # aws uses s3.amazonaws.com for example
+  server_name garage.example.com;
 
-  # We 
+  location / {
+    proxy_pass http://s3_backend;
+    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    proxy_set_header Host $host;
+  }
+}
+
+```
+
+### Exposing the web endpoint
+
+The web endpoint is a bit more complicated to configure as it listens on many different `Host` fields.
+To better understand the logic involved, you can refer to the [Exposing buckets as websites](/cookbook/exposing_websites.html) section.
+Also, for some applications, you may need to serve CORS headers: Garage can not serve them directly but we show how we can use nginx to serve them.
+You can use the following example as your starting point:
+
+```nginx
+server {
+  listen [::]:443 http2 ssl;
+  ssl_certificate     /tmp/garage.crt;
+  ssl_certificate_key /tmp/garage.key;
+
+  # We list all the Hosts fields that can access our buckets
   server_name *.web.garage
               example.com
               my-site.tld
               ;
 
   location / {
+    # Add these headers only if you want to allow CORS requests
+    # For production use, more specific rules would be better for your security
     add_header Access-Control-Allow-Origin *;
     add_header Access-Control-Max-Age 3600;
     add_header Access-Control-Expose-Headers Content-Length;
@@ -25,8 +148,7 @@ server {
       return 200;
     }
 
-    # If your do not have a Garage instance on the reverse proxy, change the URL here.
-    proxy_pass http://127.0.0.1:3902;
+    proxy_pass http://web_backend;
     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
     proxy_set_header Host $host;
   }
@@ -36,4 +158,8 @@ server {
 
 ## Apache httpd
 
+@TODO
+
 ## Traefik
+
+@TODO