Line data    Source code

       1              : use anyhow::{anyhow, Context};
       2              : use tracing::warn;
       3              : 
       4              : pub const RESIZE_SWAP_BIN: &str = "/neonvm/bin/resize-swap";
       5              : 
       6            0 : pub fn resize_swap(size_bytes: u64) -> anyhow::Result<()> {
       7            0 :     // run `/neonvm/bin/resize-swap --once {size_bytes}`
       8            0 :     //
       9            0 :     // Passing '--once' causes resize-swap to delete itself after successful completion, which
      10            0 :     // means that if compute_ctl restarts later, we won't end up calling 'swapoff' while
      11            0 :     // postgres is running.
      12            0 :     //
      13            0 :     // NOTE: resize-swap is not very clever. If present, --once MUST be the first arg.
      14            0 :     let child_result = std::process::Command::new("/usr/bin/sudo")
      15            0 :         .arg(RESIZE_SWAP_BIN)
      16            0 :         .arg("--once")
      17            0 :         .arg(size_bytes.to_string())
      18            0 :         .spawn();
      19              : 
      20            0 :     if matches!(&child_result, Err(e) if e.kind() == std::io::ErrorKind::NotFound) {
      21            0 :         warn!("ignoring \"not found\" error from resize-swap to avoid swapoff while compute is running");
      22            0 :         return Ok(());
      23            0 :     }
      24            0 : 
      25            0 :     child_result
      26            0 :         .context("spawn() failed")
      27            0 :         .and_then(|mut child| child.wait().context("wait() failed"))
      28            0 :         .and_then(|status| match status.success() {
      29            0 :             true => Ok(()),
      30            0 :             false => Err(anyhow!("process exited with {status}")),
      31            0 :         })
      32            0 :         // wrap any prior error with the overall context that we couldn't run the command
      33            0 :         .with_context(|| {
      34            0 :             format!("could not run `/usr/bin/sudo {RESIZE_SWAP_BIN} --once {size_bytes}`")
      35            0 :         })
      36            0 : }