Add tar.gz support to the nodejs runtime Proxy (#235)

* Add tar.gz support to the nodejs runtime Proxy

This new feature will allow for more versatile deployment packages and greater flexibility in handling compressed files. Giving an alternative to zip files.

this feature does not impact the current functionality of the current proxy

* fix whitespace and eol

* whitespace + eol

* Change error message to handle test case There was an error uncompressing the action archive.

Author: Luke-Roy-IBM

core/nodejsActionBase/runner.js

@@ -27,7 +27,11 @@ const path = require('path');
 function initializeActionHandler(message) {
     if (message.binary) {
         // The code is a base64-encoded zip file.
-        return unzipInTmpDir(message.code)
+        ext = detectFileType(message.code)
+        if (ext == 'unsupported'){
+            return Promise.reject("There was an error uncompressing the action archive.");
+        }
+        return extractInTmpDir(message.code)
             .then(moduleDir => {
                 let parts = splitMainHandler(message.main);
                 if (parts === undefined) {
@@ -138,21 +142,33 @@ class NodeActionRunner {
  * Note that this makes heavy use of shell commands because the environment is expected
  * to provide the required executables.
  */
-function unzipInTmpDir(zipFileContents) {
+function extractInTmpDir(archiveFileContents) {
     const mkTempCmd = "mktemp -d XXXXXXXX";
     return exec(mkTempCmd).then(tmpDir => {
         return new Promise((resolve, reject) => {
-            const zipFile = path.join(tmpDir, "action.zip");
-            fs.writeFile(zipFile, zipFileContents, "base64", err => {
-                if (!err) resolve(zipFile);
+            ext = detectFileType(archiveFileContents)
+            if (ext == 'unsupported'){
+                reject("There was an error Detecting the File type");
+            }
+            const archiveFile = path.join(tmpDir, "action."+ ext);
+            fs.writeFile(archiveFile, archiveFileContents, "base64", err => {
+                if (!err) resolve(archiveFile);
                 else reject("There was an error reading the action archive.");
             });
         });
-    }).then(zipFile => {
+    }).then(archiveFile => {
         return exec(mkTempCmd).then(tmpDir => {
-            return exec("unzip -qq " + zipFile + " -d " + tmpDir)
+            if (ext === 'zip') {
+                return exec("unzip -qq " + archiveFile + " -d " + tmpDir)
+                .then(res => path.resolve(tmpDir))
+                .catch(error => Promise.reject("There was an error uncompressing the action archive."));
+            } else if (ext === 'tar.gz') {
+                return exec("tar -xzf " + archiveFile + " -C " + tmpDir + " > /dev/null")
                 .then(res => path.resolve(tmpDir))
                 .catch(error => Promise.reject("There was an error uncompressing the action archive."));
+            } else {
+                  return Promise.reject("There was an error uncompressing the action archive.");
+            }
         });
     });
 }
@@ -198,3 +214,22 @@ module.exports = {
     NodeActionRunner,
     initializeActionHandler
 };
+
+// helper function to detect if base64string is zip or tar.gz
+// and returns the file ending
+function detectFileType(base64String) {
+    // Decode the base64 string into binary data
+    const binaryData = Buffer.from(base64String, 'base64');
+
+    // Examine the first few bytes of the binary data to determine the file type
+    const magicNumber = binaryData.slice(0, 4).toString('hex');
+
+    if (magicNumber === '504b0304') {
+      return 'zip';
+    // GZIP: 1f8b0808 maximum compression level,  1f8b0800 default compression
+    } else if (magicNumber === '1f8b0808' || magicNumber === '1f8b0800') {
+      return 'tar.gz';
+    } else {
+        return 'unsupported';
+    }
+}