refactor: reorganize main.rs

src/nsupdate.rs

@@ -0,0 +1,111 @@
+use std::{
+    ffi::OsStr,
+    net::IpAddr,
+    path::Path,
+    process::{ExitStatus, Stdio},
+    time::Duration,
+};
+
+use tokio::io::AsyncWriteExt;
+use tracing::{debug, warn};
+
+#[tracing::instrument(level = "trace", ret(level = "warn"))]
+pub async fn nsupdate(
+    ip: IpAddr,
+    ttl: Duration,
+    key_file: Option<&Path>,
+    records: &[&str],
+) -> std::io::Result<ExitStatus> {
+    let mut cmd = tokio::process::Command::new("nsupdate");
+    if let Some(key_file) = key_file {
+        cmd.args([OsStr::new("-k"), key_file.as_os_str()]);
+    }
+    debug!("spawning new process");
+    let mut child = cmd
+        .stdin(Stdio::piped())
+        .spawn()
+        .inspect_err(|err| warn!("failed to spawn child: {err}"))?;
+    let mut stdin = child.stdin.take().expect("stdin not present");
+    debug!("sending update request");
+    stdin
+        .write_all(update_ns_records(ip, ttl, records).as_bytes())
+        .await
+        .inspect_err(|err| warn!("failed to write to the stdin of nsupdate: {err}"))?;
+    debug!("closing stdin");
+    stdin
+        .shutdown()
+        .await
+        .inspect_err(|err| warn!("failed to close stdin to nsupdate: {err}"))?;
+    debug!("waiting for nsupdate to exit");
+    child
+        .wait()
+        .await
+        .inspect_err(|err| warn!("failed to wait for child: {err}"))
+}
+
+fn update_ns_records(ip: IpAddr, ttl: Duration, records: &[&str]) -> String {
+    use std::fmt::Write;
+    let ttl_s: u64 = ttl.as_secs();
+
+    let rec_type = match ip {
+        IpAddr::V4(_) => "A",
+        IpAddr::V6(_) => "AAAA",
+    };
+    let mut cmds = String::from("server 127.0.0.1\n");
+    for &record in records {
+        writeln!(cmds, "update delete {record} {ttl_s} IN {rec_type}").unwrap();
+        writeln!(cmds, "update add    {record} {ttl_s} IN {rec_type} {ip}").unwrap();
+    }
+    writeln!(cmds, "send\nquit").unwrap();
+    cmds
+}
+
+#[cfg(test)]
+mod test {
+    use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+
+    use insta::assert_snapshot;
+
+    use super::update_ns_records;
+    use crate::DEFAULT_TTL;
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn expected_update_string_A() {
+        assert_snapshot!(update_ns_records(
+        IpAddr::V4(Ipv4Addr::LOCALHOST),
+        DEFAULT_TTL,
+        &["example.com.", "example.org.", "example.net."],
+    ), @r###"
+        server 127.0.0.1
+        update delete example.com. 60 IN A
+        update add    example.com. 60 IN A 127.0.0.1
+        update delete example.org. 60 IN A
+        update add    example.org. 60 IN A 127.0.0.1
+        update delete example.net. 60 IN A
+        update add    example.net. 60 IN A 127.0.0.1
+        send
+        quit
+        "###);
+    }
+
+    #[test]
+    #[allow(non_snake_case)]
+    fn expected_update_string_AAAA() {
+        assert_snapshot!(update_ns_records(
+        IpAddr::V6(Ipv6Addr::LOCALHOST),
+        DEFAULT_TTL,
+        &["example.com.", "example.org.", "example.net."],
+    ), @r###"
+        server 127.0.0.1
+        update delete example.com. 60 IN AAAA
+        update add    example.com. 60 IN AAAA ::1
+        update delete example.org. 60 IN AAAA
+        update add    example.org. 60 IN AAAA ::1
+        update delete example.net. 60 IN AAAA
+        update add    example.net. 60 IN AAAA ::1
+        send
+        quit
+        "###);
+    }
+}