Fix not preserving uid and/or gid

src/inject-cache.ts

@@ -1,6 +1,6 @@
 import fs from 'fs/promises';
 import path from 'path';
-import { CacheOptions, Opts, getCacheMap, getMountArgsString, getTargetPath } from './opts.js';
+import { CacheOptions, Opts, getCacheMap, getMountArgsString, getTargetPath, getUID, getGID } from './opts.js';
 import { run } from './run.js';
 import { notice } from '@actions/core';
 
@@ -19,13 +19,21 @@ async function injectCache(cacheSource: string, cacheOptions: CacheOptions, scra
     const targetPath = getTargetPath(cacheOptions);
     const mountArgs = getMountArgsString(cacheOptions);
 
+    // If UID OR GID are set, then add chown to restore files ownership.
+    let ownershipCommand = "";
+    const uid = getUID(cacheOptions);
+    const gid = getGID(cacheOptions);
+    if (uid !== "" || gid !== "") {
+        ownershipCommand = `&& chown -R ${uid}:${gid} ${targetPath}`
+    }
+
     // Prepare Dancefile to Access Caches
     const dancefileContent = `
 FROM busybox:1
 COPY buildstamp buildstamp
 RUN --mount=${mountArgs} \
     --mount=type=bind,source=.,target=/var/dance-cache \
-    cp -p -R /var/dance-cache/. ${targetPath} || true
+    cp -p -R /var/dance-cache/. ${targetPath} ${ownershipCommand} || true
 `;
     await fs.writeFile(path.join(scratchDir, 'Dancefile.inject'), dancefileContent);
     console.log(dancefileContent);

src/opts.ts

@@ -83,6 +83,34 @@ export function getTargetPath(cacheOptions: CacheOptions): TargetPath {
   }
 }
 
+export function getUID(cacheOptions: CacheOptions): string {
+  if (typeof cacheOptions === "string") {
+    // only the target path is provided
+    return "";
+  } else {
+    // object is provided
+    if ("uid" in cacheOptions && cacheOptions.uid !== undefined) {
+      return cacheOptions.uid.toString();
+    } else {
+      return "";
+    }
+  }
+}
+
+export function getGID(cacheOptions: CacheOptions): string {
+  if (typeof cacheOptions === "string") {
+    // only the target path is provided
+    return "";
+  } else {
+    // object is provided
+    if ("gid" in cacheOptions && cacheOptions.gid !== undefined) {
+      return cacheOptions.gid.toString();
+    } else {
+      return "";
+    }
+  }
+}
+
 /**
  * Convert a cache options to a string that is passed to --mount=
  * @param CacheOptions The cache options to convert to a string

tests/opts.test.ts

@@ -1,5 +1,5 @@
 import { expect, test } from 'vitest'
-import { getCacheMap, getTargetPath, getMountArgsString, parseOpts } from '../src/opts.js'
+import { getCacheMap, getTargetPath, getMountArgsString, parseOpts, getUID, getGID } from '../src/opts.js'
 
 test('parseOpts with no arguments', () => {
     const opts = parseOpts([])
@@ -94,3 +94,41 @@ test('getMountArgsString with object', () => {
     const mountString = getMountArgsString(cacheOptions)
     expect(mountString).toBe('type=cache,target=targetPath,shared=true,id=1')
 })
+
+test('getUID with string', () => {
+    const cacheOptions = 'targetPath'
+    const uid = getUID(cacheOptions)
+    expect(uid).toBe('')
+})
+
+
+test('getUID with object without uid', () => {
+    const cacheOptions = { target: 'targetPath', shared: true, id: 1 }
+    const uid = getUID(cacheOptions)
+    expect(uid).toBe('')
+})
+
+test('getUID with object with uid', () => {
+    const cacheOptions = { target: 'targetPath', shared: true, id: 1, uid: 1000 }
+    const uid = getUID(cacheOptions)
+    expect(uid).toBe('1000')
+})
+
+test('getGID with string', () => {
+    const cacheOptions = 'targetPath'
+    const gid = getGID(cacheOptions)
+    expect(gid).toBe('')
+})
+
+
+test('getGID with object without gid', () => {
+    const cacheOptions = { target: 'targetPath', shared: true, id: 1 }
+    const gid = getGID(cacheOptions)
+    expect(gid).toBe('')
+})
+
+test('getGID with object with gid', () => {
+    const cacheOptions = { target: 'targetPath', shared: true, id: 1, gid: 1000 }
+    const gid = getGID(cacheOptions)
+    expect(gid).toBe('1000')
+})