remove toolchains sometimes

src/bisect.rs

@@ -107,6 +107,8 @@ pub fn process_job(job: Job, conn: &Connection) -> Result<()> {
 
     trace!(?bisect, "Finished bisection job");
 
+    crate::toolchain::clean_toolchains()?;
+
     Ok(())
 }
 

src/main.rs

@@ -2,6 +2,7 @@
 
 mod bisect;
 mod db;
+mod toolchain;
 
 use std::sync::{mpsc, Arc, Mutex};
 
@@ -50,6 +51,8 @@ async fn main() -> color_eyre::Result<()> {
 
     db::setup(&worker_conn).wrap_err("db setup")?;
 
+    toolchain::clean_toolchains()?;
+
     let app = Router::new()
         .route("/", get(|| async { index_html() }))
         .route("/bisect/:id", get(get_bisection))

src/toolchain.rs

@@ -0,0 +1,73 @@
+use std::process::Command;
+
+use color_eyre::{
+    eyre::{eyre, Context},
+    Result,
+};
+use tracing::debug;
+
+const MAX_BISECTOR_TOOLCHAINS: usize = 15;
+
+#[tracing::instrument]
+pub fn clean_toolchains() -> Result<()> {
+    let toolchains = get_toolchains()?;
+    let for_removal = filter_toolchain_for_removal(toolchains);
+    if !for_removal.is_empty() {
+        remove_toolchains(&for_removal)?;
+    }
+
+    Ok(())
+}
+
+fn filter_toolchain_for_removal(mut toolchains: Vec<String>) -> Vec<String> {
+    toolchains.retain(|toolchain| toolchain.starts_with("bisector-"));
+
+    let amount = toolchains.len();
+    if amount <= MAX_BISECTOR_TOOLCHAINS {
+        debug!(%amount, "No toolchains removed");
+        return Vec::new();
+    }
+
+    let to_remove = amount - MAX_BISECTOR_TOOLCHAINS;
+
+    toolchains.into_iter().take(to_remove).collect()
+}
+
+fn get_toolchains() -> Result<Vec<String>> {
+    let mut command = Command::new("rustup");
+    command.args(["toolchain", "list"]);
+
+    let output = command
+        .output()
+        .wrap_err("running `rustup toolchain list`")?;
+
+    if output.status.success() {
+        let stdout =
+            String::from_utf8(output.stdout).wrap_err("rustup returned non-utf-8 bytes")?;
+
+        let toolchains = stdout.lines().map(ToOwned::to_owned).collect();
+
+        Ok(toolchains)
+    } else {
+        let stderr = String::from_utf8_lossy(&output.stderr).into_owned();
+        Err(eyre!("`rustup toolchain list` failed").wrap_err(stderr))
+    }
+}
+
+fn remove_toolchains(toolchains: &[String]) -> Result<()> {
+    debug!(?toolchains, "Removing toolchains");
+    let mut command = Command::new("rustup");
+    command.args(["toolchain", "remove"]);
+    command.args(toolchains);
+
+    let output = command
+        .output()
+        .wrap_err("running `rustup toolchain remove`")?;
+
+    if output.status.success() {
+        return Ok(());
+    }
+
+    let stderr = String::from_utf8_lossy(&output.stderr).into_owned();
+    Err(eyre!("`rustup toolchain remove` failed").wrap_err(stderr))
+}