Add support for running on Windows via WSL (#97)

Signed-off-by: Keith Zantow <kzantow@gmail.com>

.github/workflows/test.yml

@@ -26,8 +26,16 @@ jobs:
       - run: git diff --exit-code
 
   test-on-fixture-dirs:
-    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
     steps:
+      - uses: Vampire/setup-wsl@v1
+        if: ${{ matrix.os == 'windows-latest' }}
+        with:
+          distribution: Alpine
+
       - uses: actions/checkout@v2
         with:
           path: ./

README.md

@@ -145,6 +145,18 @@ Output parameters:
 `cmd` can be referenced in a workflow like other output parameters:
 `${{ steps.<step-id>.outputs.cmd }}`
 
+## Windows
+
+Windows is currently supported via Windows Subsystem for Linux (WSL). It is
+required to set up a WSL distribution prior to invoking the `sbom-action`, for
+example, you can add the small Alpine image:
+
+```yaml
+- uses: Vampire/setup-wsl@v1
+  with:
+    distribution: Alpine
+```
+
 ## Diagnostics
 
 This action makes extensive use of GitHub Action debug logging,

src/github/SyftGithubAction.ts

@@ -69,6 +69,39 @@ export function getArtifactName(): string {
   return `${repo}-${job}${stepName}.${extension}`;
 }
 
+/**
+ * Maps the given parameter to a Windows Subsystem for Linux style path
+ * @param arg
+ */
+export function mapToWSLPath(arg: string) {
+  return arg.replace(
+    /^([A-Z]):(.*)$/,
+    (v, drive, path) => `/mnt/${drive.toLowerCase()}${path.replace(/\\/g, "/")}`
+  );
+}
+
+/**
+ * Execute directly for linux & macOS and use WSL for Windows
+ * @param cmd command to execute
+ * @param args command args
+ * @param options command options
+ */
+async function execute(
+  cmd: string,
+  args: string[],
+  options?: exec.ExecOptions
+) {
+  if (process.platform === "win32") {
+    return await exec.exec(
+      "wsl",
+      [mapToWSLPath(cmd), ...args.map(mapToWSLPath)],
+      options
+    );
+  } else {
+    return exec.exec(cmd, args, options);
+  }
+}
+
 /**
  * Gets a reference to the syft command and executes the syft action
  * @param input syft input parameters
@@ -127,7 +160,7 @@ async function executeSyft({ input, format }: SyftOptions): Promise<string> {
   });
 
   const exitCode = await core.group("Executing Syft...", async () =>
-    exec.exec(cmd, args, {
+    execute(cmd, args, {
       env,
       outStream,
       listeners: {
@@ -167,12 +200,11 @@ export async function downloadSyft(): Promise<string> {
   const installPath = await cache.downloadTool(url);
 
   // Make sure the tool's executable bit is set
-  await exec.exec(`chmod +x ${installPath}`);
+  const syftBinaryPath = `${installPath}_${name}`;
 
-  const cmd = `${installPath} -b ${installPath}_${name} ${version}`;
-  await exec.exec(cmd);
+  await execute("sh", [installPath, "-d", "-b", syftBinaryPath, version]);
 
-  return `${installPath}_${name}/${name}`;
+  return `${syftBinaryPath}/${name}`;
 }
 
 /**

tests/SyftGithubAction.test.ts

@@ -14,7 +14,7 @@ import * as os from "os";
 import * as path from "path";
 import * as action from "../src/github/SyftGithubAction";
 import {
-  downloadSyft,
+  downloadSyft, mapToWSLPath,
   runAndFailBuildOnException
 } from "../src/github/SyftGithubAction";
 
@@ -274,5 +274,11 @@ describe("Action", () => {
     });
 
     expect(action.getArtifactName()).toBe("something-something-image-image.spdx.json");
-  })
+  });
+
+  it ("properly maps paths for WSL", () => {
+    expect(mapToWSLPath("basic arg")).toBe("basic arg");
+    expect(mapToWSLPath("D:\\Some\\Path")).toBe("/mnt/d/Some/Path");
+    expect(mapToWSLPath("C:\\Some\\Path")).toBe("/mnt/c/Some/Path");
+  });
 });