Update readme

Cargo.toml

@@ -29,3 +29,6 @@ dirs = "5"
 strip = "symbols"
 lto = "thin"
 codegen-units = 1
+
+[package.metadata.deb.systemd-units]
+unit-scripts = "systemd/"

README.md

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+# DDNS for Cloudflare
+
+Small binary to update Cloudflare DNS entries via a config file.
+
+## How does it work
+
+This system is split into two portions, the binary itself and an external timer
+that periodically executes the binary.
+
+To install the binary, either build your own `.deb` file or find a release. More
+distro support is appreciated but not currently promised.
+
+An external timer can be a system provided one or something like `crontab`.
+For convenience, a `systemd` system and timer file is provided that activates it
+on an hourly interval. This is automatically installed if you use the `.deb`.
+
+The binary contains various subcommands:
+
+|Subcommand|Description|
+|----------|-----------|
+|`run`|Reads from a config file and calls into Cloudflare's API|
+|`list`|Read the config file to list information about your zones|
+
+This binary must be activated at your preferred interval via an external timer.
+
+This only supports updating one IP address to any number of zones and DNS
+entries. For another IP address, install and run this on the machine with
+different IP address.
+
+## Installation
+
+First, create an initial file at `/etc/cloudflare-ddns.toml`. Populate it with
+the following:
+
+```toml
+[account]
+email = "your@email.com"
+api_key = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+
+[ip_reflector]
+ipv4 = "https://what.is.my.ipv4.example"
+ipv6 = "https://what.is.my.ipv6.example"
+
+[zone."example.com"]
+id = "deadbeefdeadbeefdeadbeefdeadbeef"
+```
+
+### `account` section
+
+The `email` should be the email associated with your Cloudflare account.
+
+The `api_key` field should be populated with your Global API Key. This is found
+at on your [account profile].
+
+[account profile]: https://dash.cloudflare.com/profile/api-tokens
+
+### `ip_reflector` section
+
+The `ipv4` and `ipv6` fields should be populated with a URL that when provided
+a `GET` request, returns the IP address in the body as a string, without a
+newline.
+
+For example, `curl` should return something similar to this:
+
+```
+$ curl https://what.is.my.ipv4.example
+1.2.3.4%
+```
+The `%` is added by `curl` to indicate no line ending.
+
+### `zone` section
+
+Each zone subsection should contain a website registered to your account. Each
+zone needs an `id`, which can be found on the Overview tab of the respective
+website.
+
+Once you've populated all fields, run `cloudflare-ddns list` to list the ids of
+each DNS entry:
+
+```
+example.com (deadbeefdeadbeefdeadbeefdeadbeef)
++--------------------+------+--------------------------+---------+----------------------------------+
+|               Name | Type | IP Address               | Proxied | Id                               |
++--------------------+------+--------------------------+---------+----------------------------------+
+|        example.com | A    | 6.6.6.6                  | false   | fefefefefefefefefefefefefefefefe |
++--------------------+------+--------------------------+---------+----------------------------------+
+|   irys.example.com | A    | 6.6.6.6                  | true    | c0ffeec0ffeec0ffeec0ffeec0ffeec0 |
++--------------------+------+--------------------------+---------+----------------------------------+
+| suisei.example.com | AAAA | 1111:11::1111            | true    | 1337c0d31337c0d31337c0d31337c0d3 |
++--------------------+------+--------------------------+---------+----------------------------------+
+```
+
+This lists all relevant data necessary for dynamically updating each DNS entry.
+
+For each DNS entry for `example.com` you want to dynamically update, create an
+entry as follows:
+
+```toml
+[[zone."example.com".record]]
+name = "@" # Use @ for the root domain
+id = "fefefefefefefefefefefefefefefefe"
+proxy = false
+type = "A"
+
+[[zone."example.com".record]]
+name = "irys"
+id = "c0ffeec0ffeec0ffeec0ffeec0ffeec0"
+proxy = true
+type = "A"
+
+[[zone."example.com".record]]
+name = "suisei"
+id = "1337c0d31337c0d31337c0d31337c0d3"
+proxy = true
+type = "AAAA"
+```
+
+A full example config can be found in the repo.
+
+At this point, you can run `cloudflare-ddns run` to verify that everything
+works. If you run into issues, you can provide `--log=debug` or `--log=trace`
+for more information.
+
+If successful, attempt to trigger it via the external timer. If that is
+successful, installation is complete.
+
+## Building packages
+
+A `.deb` package is created via [`cargo-deb`].
+
+[`cargo-deb`]: https://github.com/kornelski/cargo-deb

systemd/cloudflare-ddns.service

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+[Unit]
+Description=Run the Cloudflare DDNS script
+Wants=network-online.target
+After=network-online.target
+
+[Service]
+Type=oneshot
+ExecStart=/usr/bin/cloudflare-ddns run
+
+# Security
+NoNewPrivileges=true
+
+# Sandboxing config
+ProtectSystem=true
+PrivateTmp=true
+PrivateDevices=true
+ProtectHostname=true
+ProtectClock=true
+ProtectKernelTunables=true
+ProtectKernelModules=true
+ProtectKernelLogs=true
+ProtectControlGroups=true
+RestrictNamespaces=true
+LockPersonality=true
+MemoryDenyWriteExecute=true
+RestrictRealtime=true
+RestrictSUIDSGID=true
+
+[Install]
+WantedBy=multi-user.target

systemd/cloudflare-ddns.timer

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+[Unit]
+Description=Run the Cloudflare DDNS script hourly
+
+[Timer]
+OnBootSec=1min
+OnUnitActiveSec=1hr
+
+[Install]
+WantedBy=timers.target