support "unstable" version option on all platforms except macOS

The tailscale repo does not get tagged for unstable builds, so the best we can do when
building macOS from source is to build from the HEAD of `main`.

Updates tailscale/corp#32813

Signed-off-by: Percy Wegmann <percy@tailscale.com>

.github/workflows/test.yml

@@ -11,7 +11,7 @@ jobs:
   # Matrix test for all supported platforms and architectures
   
   integration-tests:
-    name: Test ${{ matrix.os }} (${{ matrix.arch }})
+    name: ${{ matrix.os }} (${{ matrix.arch }}) tailscale-${{ matrix.version }}
     strategy:
       fail-fast: false
       matrix:
@@ -20,31 +20,54 @@ jobs:
           - os: ubuntu-latest
             runner-os: Linux
             arch: amd64
+            version: latest
+
+          # Try unstable too
+          - os: ubuntu-latest
+            runner-os: Linux
+            arch: amd64
+            version: unstable
+
+          # Try a pinned version
+          - os: ubuntu-latest
+            runner-os: Linux
+            arch: amd64
+            version: 1.82.0
           
           # Linux tests (ARM64)
           - os: ubuntu-24.04-arm
             runner-os: Linux
             arch: arm64
+            version: latest
           
           # Windows tests (AMD64)
           - os: windows-latest
             runner-os: Windows
             arch: amd64
+            version: latest
+
+          - os: windows-latest
+            runner-os: Windows
+            arch: amd64
+            version: unstable
           
           # Windows tests (ARM64)
           - os: windows-11-arm
             runner-os: Windows
             arch: arm64
+            version: latest
             
           # macOS intel
           - os: macos-13
             runner-os: macOS
             arch: amd64
+            version: latest
           
           # macOS ARM
           - os: macos-14
             runner-os: macOS
             arch: arm64
+            version: latest
     
     runs-on: ${{ matrix.os }}
     
@@ -72,7 +95,7 @@ jobs:
           oauth-client-id: ${{ secrets.TS_AUTH_KEYS_OAUTH_CLIENT_ID }}
           oauth-client-secret: ${{ secrets.TS_AUTH_KEYS_OAUTH_CLIENT_SECRET }}
           tags: "tag:ci"
-          version: "1.82.0"
+          version: "${{ matrix.version }}"
           use-cache: false
           timeout: "5m"
           retry: 3

Makefile

@@ -26,7 +26,7 @@ install:
 	npm install
 
 # Build the TypeScript code
-build: clean
+build: clean format
 	npm run build
 
 # Lint the TypeScript code

dist/index.js

@@ -41204,10 +41204,15 @@ async function run() {
         }
         // Get and validate inputs
         const config = await getInputs();
+        if (runnerOS === "macOS" &&
+            config.version === "unstable" &&
+            config.useCache) {
+            throw new Error("Caching of unstable releases is not supported on macOS runners");
+        }
         // Validate authentication
         validateAuth(config);
         // Resolve version
-        config.resolvedVersion = await resolveVersion(config.version);
+        config.resolvedVersion = await resolveVersion(config.version, runnerOS);
         core.info(`Resolved Tailscale version: ${config.resolvedVersion}`);
         // Set architecture
         config.arch = getTailscaleArch(runnerOS);
@@ -41268,13 +41273,17 @@ function validateAuth(config) {
         throw new Error("OAuth identity empty, please provide either an auth key or OAuth secret and tags.");
     }
 }
-async function resolveVersion(version) {
-    if (version === "latest") {
+async function resolveVersion(version, runnerOS) {
+    if (runnerOS === "macOS" && version === "unstable") {
+        return "main";
+    }
+    if (version === "latest" || version === "unstable") {
+        let path = version === "unstable" ? "unstable" : "stable";
         const { stdout } = await exec.getExecOutput("curl", [
             "-H",
             "user-agent:action-setup-tailscale",
             "-s",
-            "https://pkgs.tailscale.com/stable/?mode=json",
+            `https://pkgs.tailscale.com/${path}/?mode=json`,
         ]);
         const response = JSON.parse(stdout);
         return response.Version;
@@ -41656,8 +41665,7 @@ function sleep(ms) {
     return new Promise((resolve) => setTimeout(resolve, ms));
 }
 function generateCacheKey(config, runnerOS) {
-    // Don't cache if version is latest or if caching is disabled
-    if (config.resolvedVersion === "latest" || !config.useCache) {
+    if (!config.useCache) {
         return undefined;
     }
     return `action-setup-tailscale/${config.resolvedVersion}/${runnerOS}-${config.arch}`;

src/main.ts

@@ -114,11 +114,21 @@ async function run(): Promise<void> {
     // Get and validate inputs
     const config = await getInputs();
 
+    if (
+      runnerOS === "macOS" &&
+      config.version === "unstable" &&
+      config.useCache
+    ) {
+      throw new Error(
+        "Caching of unstable releases is not supported on macOS runners"
+      );
+    }
+
     // Validate authentication
     validateAuth(config);
 
     // Resolve version
-    config.resolvedVersion = await resolveVersion(config.version);
+    config.resolvedVersion = await resolveVersion(config.version, runnerOS);
     core.info(`Resolved Tailscale version: ${config.resolvedVersion}`);
 
     // Set architecture
@@ -186,17 +196,26 @@ function validateAuth(config: TailscaleConfig): void {
   }
 }
 
-async function resolveVersion(version: string): Promise<string> {
-  if (version === "latest") {
+async function resolveVersion(
+  version: string,
+  runnerOS: string
+): Promise<string> {
+  if (runnerOS === "macOS" && version === "unstable") {
+    return "main";
+  }
+
+  if (version === "latest" || version === "unstable") {
+    let path = version === "unstable" ? "unstable" : "stable";
     const { stdout } = await exec.getExecOutput("curl", [
       "-H",
       "user-agent:action-setup-tailscale",
       "-s",
-      "https://pkgs.tailscale.com/stable/?mode=json",
+      `https://pkgs.tailscale.com/${path}/?mode=json`,
     ]);
     const response = JSON.parse(stdout);
     return response.Version;
   }
+
   return version;
 }
 
@@ -665,8 +684,7 @@ function generateCacheKey(
   config: TailscaleConfig,
   runnerOS: string
 ): string | undefined {
-  // Don't cache if version is latest or if caching is disabled
-  if (config.resolvedVersion === "latest" || !config.useCache) {
+  if (!config.useCache) {
     return undefined;
   }