add useFinalCopy option

Author: Didier SENMARTIN

Diff for: README.md

@@ -416,6 +416,18 @@ functions:
     vendor: ./hello-vendor # The option is also available at the function level
 ```
 
+### Copy dependencies instead of linking
+
+Before final packaging, a link is created in .serverless folder for python dependencies.
+If it is not possible to create a symbolic link, dependencies can be copied instead of linked
+whith the foloowing option:
+
+```yaml
+custom:
+  pythonRequirements:
+    useFinalCopy: true
+```
+
 ## Manual invocations
 
 The `.requirements` and `requirements.zip`(if using zip support) files are left

Diff for: index.js

@@ -58,6 +58,7 @@ class ServerlessPythonRequirements {
         pipCmdExtraArgs: [],
         noDeploy: [],
         vendor: '',
+        useFinalCopy: false,
       },
       (this.serverless.service.custom &&
         this.serverless.service.custom.pythonRequirements) ||

Diff for: lib/pip.js

@@ -778,7 +778,9 @@ async function installAllRequirements() {
       reqsInstalledAt != symlinkPath
     ) {
       // Windows can't symlink so we have to use junction on Windows
-      if (process.platform == 'win32') {
+      if (this.serverless.service.custom.pythonRequirements.useFinalCopy) {
+        fse.copySync(reqsInstalledAt, symlinkPath);
+      } else if (process.platform == 'win32') {
         fse.symlink(reqsInstalledAt, symlinkPath, 'junction');
       } else {
         fse.symlink(reqsInstalledAt, symlinkPath);