Add server installation instructions

docs/server-installation.md

@@ -0,0 +1,43 @@
+# Server installation
+
+## DNS configuration
+
+One domain and one subdomain must point to the IP address of a [dedicated server](server-requirements.md).
+
+| FQDN           | Record type | Address |
+| -------------- | ----------- | ------- |
+| {{DOMAIN}}     | A           | X.X.X.X |
+| git.{{DOMAIN}} | A           | X.X.X.X |
+
+## Network configuration
+
+### Inbound
+
+| Port | Transport | Application      |
+| ---- | --------- | ---------------- |
+| 22   | TCP       | SSH              |
+| 80   | TCP, UDP  | HTTP/(1.1, 2, 3) |
+| 443  | TCP, UDP  | HTTP/(1.1, 2, 3) |
+| 521  | TCP       | SSH              |
+
+### Outbound
+
+| Port | Transport | Application |
+| ---- | --------- | ----------- |
+| 465  | TCP       | SMTP        |
+
+### OS installation
+
+Download and boot the ISO image `amd64` of [Debian](https://www.debian.org/distrib/netinst)
+
+Select :
+
+-   "Advanced options ..."
+-   "... Automated install"
+
+The network is automatically configured with DHCP, you can also configure it manually.
+
+At the prompt "Location of initial preconfiguration file:", enter the url : `raw.githubusercontent.com/01-edu/public/master/scripts/preseed.cfg` and select "Continue"
+
+Let us know when the server's remote access is ready, we will configure it.
+