test/util: improve run_ucmd_as_root for CICD

* ensure that `fn run_no_wait` is only invoked if the system running the
test has `sudo` in $path

Previously, if run inside CICD, calling `fn run_ucmd_as_root`
would provoke `fn run_no_wait` to panic because there's no `sudo`.

tests/common/util.rs

@@ -1370,6 +1370,8 @@ pub fn expected_result(ts: &TestScenario, args: &[&str]) -> std::result::Result<
 /// To check if i) non-interactive sudo is possible and ii) if sudo works, this runs:
 /// 'sudo -E --non-interactive whoami' first.
 ///
+/// This return an `Err()` if run inside CICD because there's no 'sudo'.
+///
 /// Example:
 ///
 /// ```no_run
@@ -1381,7 +1383,7 @@ pub fn expected_result(ts: &TestScenario, args: &[&str]) -> std::result::Result<
 /// if let Ok(result) = run_ucmd_as_root(&ts, &[]) {
 /// result.stdout_is(expected);
 /// } else {
-/// print!("TEST SKIPPED");
+/// println!("TEST SKIPPED");
 /// }
 /// }
 ///```
@@ -1390,29 +1392,34 @@ pub fn run_ucmd_as_root(
  ts: &TestScenario,
  args: &[&str],
 ) -> std::result::Result<CmdResult, String> {
- // Apparently CICD environment has no `sudo`?
- if ts
- .cmd_keepenv("sudo")
- .env("LC_ALL", "C")
- .arg("-E")
- .arg("--non-interactive")
- .arg("whoami")
- .run()
- .stdout_str()
- .trim()
- != "root"
+ // check if we can run 'sudo'
+ log_info("run", "sudo -E --non-interactive whoami");
+ match Command::new("sudo")
+ .args(&["-E", "--non-interactive", "whoami"])
+ .output()
  {
- Err("\"sudo whoami\" didn't return \"root\"".to_string())
- } else {
- Ok(ts
- .cmd_keepenv("sudo")
- .env("LC_ALL", "C")
- .arg("-E")
- .arg("--non-interactive")
- .arg(&ts.bin_path)
- .arg(&ts.util_name)
- .args(args)
- .run())
+ Ok(output) if String::from_utf8_lossy(&output.stdout).eq("root\n") => {
+ // we can run sudo and we're root
+ // run ucmd as root:
+ Ok(ts
+ .cmd_keepenv("sudo")
+ .env("LC_ALL", "C")
+ .arg("-E")
+ .arg("--non-interactive")
+ .arg(&ts.bin_path)
+ .arg(&ts.util_name)
+ .args(args)
+ .run())
+ }
+ Ok(output)
+ if String::from_utf8_lossy(&output.stderr).eq("sudo: a password is required\n") =>
+ {
+ Err("Cannot run non-interactive sudo".to_string())
+ }
+ Ok(_output) => {
+ Err("\"sudo whoami\" didn't return \"root\"".to_string())
+ }
+ Err(e) => Err(e.to_string()),
  }
 }
 
@@ -1771,18 +1778,22 @@ mod tests {
  #[cfg(unix)]
  #[cfg(feature = "whoami")]
  fn test_run_ucmd_as_root() {
- // Skip test if we can't guarantee non-interactive `sudo`.
- if let Ok(_status) = Command::new("sudo")
- .args(&["-E", "-v", "--non-interactive"])
- .status()
+ // Skip test if we can't guarantee non-interactive `sudo`, or if we're not "root"
+ if let Ok(output) = Command::new("sudo")
+ .args(&["-E", "--non-interactive", "whoami"])
+ .output()
  {
- let ts = TestScenario::new("whoami");
- std::assert_eq!(
- run_ucmd_as_root(&ts, &[]).unwrap().stdout_str().trim(),
- "root"
- );
+ if output.status.success() && String::from_utf8_lossy(&output.stdout).eq("root\n") {
+ let ts = TestScenario::new("whoami");
+ std::assert_eq!(
+ run_ucmd_as_root(&ts, &[]).unwrap().stdout_str().trim(),
+ "root"
+ );
+ } else {
+ println!("TEST SKIPPED (we're not root)");
+ }
  } else {
- print!("TEST SKIPPED");
+ println!("TEST SKIPPED (cannot run sudo)");
  }
  }
 }