From d2de35bc239ad5488e01566f3ac6701efc4a5a00 Mon Sep 17 00:00:00 2001
From: cptpcrd <31829097+cptpcrd@users.noreply.github.com>
Date: Wed, 25 Nov 2020 18:12:52 -0500
Subject: [PATCH] Improve Ubuntu version detection

---
 src/download.ts | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/download.ts b/src/download.ts
index ba78d6a..1d8d227 100644
--- a/src/download.ts
+++ b/src/download.ts
@@ -21,12 +21,17 @@ function getRunner(): string {
         case "darwin":
             return "macos-10.15";
         case "linux":
-            // TODO: Is there better way to determine Actions runner OS?
-            if (os.release().startsWith("4.15")) {
-                return "ubuntu-16.04";
-            } else {
-                return "ubuntu-18.04";
+            for (const line of require("fs")
+                .readFileSync("/etc/os-release", {
+                    encoding: "utf8",
+                })
+                .split("\n")) {
+                if (line.startsWith("VERSION_ID=")) {
+                    return "ubuntu-" + line.substring(10).replaceAll(/["']/g, "");
+                }
             }
+
+            throw new Error("Unrecognized version of Ubuntu");
         default:
             throw new Error("Unsupported OS");
     }