From ba1d3f045d0fca79f125c165fd3cf34da249b506 Mon Sep 17 00:00:00 2001
From: "Luke D. Jones" <luke@ljones.dev>
Date: Tue, 11 Oct 2022 22:25:49 +1300
Subject: [PATCH] Add missing file

---
 daemon/src/systemd.rs | 90 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 daemon/src/systemd.rs

diff --git a/daemon/src/systemd.rs b/daemon/src/systemd.rs
new file mode 100644
index 00000000..d733265d
--- /dev/null
+++ b/daemon/src/systemd.rs
@@ -0,0 +1,90 @@
+use std::process::Command;
+
+use crate::error::RogError;
+
+/// An action for `systemctl`
+#[derive(Debug, Copy, Clone)]
+pub enum SystemdUnitAction {
+    Stop,
+    Start,
+    Restart,
+}
+
+impl From<SystemdUnitAction> for &str {
+    fn from(s: SystemdUnitAction) -> Self {
+        match s {
+            SystemdUnitAction::Stop => "stop",
+            SystemdUnitAction::Start => "start",
+            SystemdUnitAction::Restart => "restart",
+        }
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+pub enum SystemdUnitState {
+    Active,
+    Inactive,
+}
+
+impl From<SystemdUnitState> for &str {
+    fn from(s: SystemdUnitState) -> Self {
+        match s {
+            SystemdUnitState::Active => "active",
+            SystemdUnitState::Inactive => "inactive",
+        }
+    }
+}
+
+/// Change the state of a systemd unit. Blocks while running command.
+pub fn do_systemd_unit_action(action: SystemdUnitAction, unit: &str) -> Result<(), RogError> {
+    let mut cmd = Command::new("systemctl");
+    cmd.arg(<&str>::from(action));
+    cmd.arg(unit);
+
+    let status = cmd
+        .status()
+        .map_err(|err| RogError::Command(format!("{:?}", cmd), err))?;
+    if !status.success() {
+        let msg = format!("systemctl {action:?} {unit} failed: {status:?}",);
+        return Err(RogError::SystemdUnitAction(msg));
+    }
+    Ok(())
+}
+
+/// Get systemd unit state. Blocks while command is run.
+pub fn is_systemd_unit_state(state: SystemdUnitState, unit: &str) -> Result<bool, RogError> {
+    let mut cmd = Command::new("systemctl");
+    cmd.arg("is-active");
+    cmd.arg(unit);
+
+    let output = cmd
+        .output()
+        .map_err(|err| RogError::Command(format!("{:?}", cmd), err))?;
+    if output.stdout.starts_with(<&str>::from(state).as_bytes()) {
+        return Ok(true);
+    }
+    Ok(false)
+}
+
+/// Wait for a systemd unit to change to `state`. Checks state every 250ms for 3 seconds. Blocks while running wait.
+pub fn wait_systemd_unit_state(state: SystemdUnitState, unit: &str) -> Result<(), RogError> {
+    let mut cmd = Command::new("systemctl");
+    cmd.arg("is-active");
+    cmd.arg(unit);
+
+    let mut count = 0;
+
+    while count <= (4 * 3) {
+        // 3 seconds max
+        let output = cmd
+            .output()
+            .map_err(|err| RogError::Command(format!("{:?}", cmd), err))?;
+        if output.stdout.starts_with(<&str>::from(state).as_bytes()) {
+            return Ok(());
+        }
+        // fine to block here, nobody doing shit now
+        std::thread::sleep(std::time::Duration::from_millis(250));
+        count += 1;
+    }
+    Err(RogError::SystemdUnitWaitTimeout(<&str>::from(state).into()))
+}