Add qcow2 support

src/command.rs

@@ -0,0 +1,27 @@
+use std::process::Command;
+
+use anyhow::{Context, anyhow, bail};
+
+pub fn cmd(cmd: &[&str]) -> anyhow::Result<String> {
+    let [cmd, args @ ..] = cmd else {
+        bail!("missing command");
+    };
+
+    let mut command = Command::new(cmd);
+    command.args(args);
+    println!("$ {command:?}");
+    let output = command
+        .output()
+        .with_context(|| anyhow!("Failed to run {command:?}"))?;
+
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    if !output.status.success() {
+        let stderr = String::from_utf8_lossy(&output.stderr);
+        eprintln!("{command:?} failed");
+        eprintln!("stdout:\n{stdout}\n");
+        eprintln!("stderr:\n{stderr}\n");
+        bail!("{command:?} failed with exit code {}", output.status);
+    }
+
+    Ok(stdout.to_string())
+}