More docs

Cargo.toml

@@ -30,5 +30,8 @@ strip = "symbols"
 lto = "thin"
 codegen-units = 1
 
+[package.metadata.deb]
+name = "cloudflare-ddns-rs"
+
 [package.metadata.deb.systemd-units]
 unit-scripts = "systemd/"

README.md

@@ -29,8 +29,15 @@ different IP address.
 
 ## Installation
 
-First, create an initial file at `/etc/cloudflare-ddns.toml`. Populate it with
-the following:
+First, create an initial file at `/etc/cloudflare-ddns.toml`. Set the permissions
+so that it is readable and writable by `root` only:
+
+```
+# sudo touch /etc/cloudflare-ddns.toml
+# chmod 600 /etc/cloudflare-ddns.toml
+```
+
+Populate it with the following:
 
 ```toml
 [account]
@@ -129,3 +136,16 @@ successful, installation is complete.
 A `.deb` package is created via [`cargo-deb`].
 
 [`cargo-deb`]: https://github.com/kornelski/cargo-deb
+
+## Security
+
+This project attempts to take security seriously. Please note the following
+hardening notes applied by default.
+
+### Hardened `systemd` service configuration
+
+In principle, this service needs very little access to a host, and needs access
+to the internet. As a result, the default `systemd` service configuration
+aggressively restricts the capabilities of the binary to a minimum set of
+features, namely access to the internet and dependency to do so. If you believe
+more directives could be provided, please create a PR.