1 files changed, 91 insertions, 0 deletions
diff --git a/src/check.rs b/src/check.rs
new file mode 100644
index 0000000..bfde1b9
--- /dev/null
+++ b/src/check.rs
@@ -0,0 +1,91 @@
+use crate::{Check, Config, Success, STATUS};
+use anyhow::{anyhow, bail, Context, Result};
+use futures::{stream::FuturesUnordered, StreamExt};
+use log::info;
+use std::{
+    sync::Arc,
+    time::{Duration, Instant},
+};
+use tokio::{
+    process::Command,
+    time::{sleep, timeout},
+};
+
+pub async fn check_loop(config: Arc<Config>, i: usize) {
+    loop {
+        check_service(&config, i).await;
+        sleep(Duration::from_secs(config.interval)).await;
+    }
+}
+
+async fn check_service(config: &Arc<Config>, i: usize) {
+    let service = &config.services[i];
+    let mut futs = FuturesUnordered::from_iter(service.checks.iter().enumerate().map(
+        |(j, check)| async move {
+            let r = match timeout(Duration::from_secs(30), check.check()).await {
+                Ok(Ok(succ)) => Ok(succ),
+                Ok(Err(e)) => Err(e),
+                Err(_) => Err(anyhow!("timed out")),
+            };
+            info!("check {i}:{j} => {r:?}");
+            {
+                let mut g = STATUS.write().await;
+                g.insert((i, j), r);
+            }
+        },
+    ));
+    while let Some(_) = futs.next().await {}
+}
+
+impl Check {
+    pub async fn check(&self) -> Result<Success> {
+        match self {
+            Check::Systemd(sname) => {
+                let output = Command::new("systemctl")
+                    .arg("show")
+                    .arg("--no-pager")
+                    .arg(sname)
+                    .output()
+                    .await
+                    .context("systemctl")?;
+                let output = String::from_utf8(output.stdout).context("systemctl output")?;
+
+                for line in output.split("\n") {
+                    if let Some((key, value)) = line.split_once("=") {
+                        match key {
+                            "ActiveState" if value != "active" => {
+                                bail!("{value}")
+                            }
+                            _ => (),
+                        }
+                    }
+                }
+                Ok(Success::default())
+            }
+            Check::Shell { command, .. } => {
+                let args = shlex::split(&command).ok_or(anyhow!("command syntax invalid"))?;
+                let status = Command::new(args.get(0).ok_or(anyhow!("argv0 missing"))?)
+                    .args(&args[1..])
+                    .status()
+                    .await;
+
+                match status {
+                    Ok(status) if status.success() => Ok(Success::default()),
+                    Ok(status) => bail!("failed with code {}", status.code().unwrap_or(1)),
+                    Err(e) => bail!("command failed to execute: {e}"),
+                }
+            }
+            Check::Http { url, .. } => {
+                let k = Instant::now();
+                let r = reqwest::get(url).await?;
+                if !r.status().is_success() {
+                    bail!("http status: {}", r.status().as_str())
+                }
+                Ok(Success {
+                    latency: Some(k.elapsed()),
+                    ..Default::default()
+                })
+            }
+        }
+    }
+}