No-op on GHES

src/restore.ts

@@ -6,6 +6,12 @@ import * as utils from "./utils/actionUtils";
 
 async function run(): Promise<void> {
     try {
+        if (utils.isGhes()) {
+            core.info("Cache action is not supported on GHES");
+            utils.setCacheHitOutput(false);
+            return;
+        }
+
         // Validate inputs, this can cause task failure
         if (!utils.isValidEvent()) {
             utils.logWarning(

src/save.ts

@@ -6,6 +6,11 @@ import * as utils from "./utils/actionUtils";
 
 async function run(): Promise<void> {
     try {
+        if (utils.isGhes()) {
+            core.info("Cache action is not supported on GHES");
+            return;
+        }
+
         if (!utils.isValidEvent()) {
             utils.logWarning(
                 `Event Validation Error: The event type ${

src/utils/actionUtils.ts

@@ -2,6 +2,13 @@ import * as core from "@actions/core";
 
 import { Outputs, RefKey, State } from "../constants";
 
+export function isGhes(): boolean {
+    const ghUrl = new URL(
+        process.env["GITHUB_SERVER_URL"] || "https://github.com"
+    );
+    return ghUrl.hostname.toUpperCase() !== "GITHUB.COM";
+}
+
 export function isExactKeyMatch(key: string, cacheKey?: string): boolean {
     return !!(
         cacheKey &&