1 files changed, 22 insertions, 0 deletions
diff --git a/python/knot_resolver_manager/utils/which.py b/python/knot_resolver_manager/utils/which.py
new file mode 100644
index 00000000..450102f3
--- /dev/null
+++ b/python/knot_resolver_manager/utils/which.py
@@ -0,0 +1,22 @@
+import functools
+import os
+from pathlib import Path
+
+
+@functools.lru_cache(maxsize=16)
+def which(binary_name: str) -> Path:
+    """
+    Given a name of an executable, search $PATH and return
+    the absolute path of that executable. The results of this function
+    are LRU cached.
+
+    If not found, throws an RuntimeError.
+    """
+
+    possible_directories = os.get_exec_path()
+    for dr in possible_directories:
+        p = Path(dr, binary_name)
+        if p.exists():
+            return p.absolute()
+
+    raise RuntimeError(f"Executable {binary_name} was not found in $PATH")