Python middleware initialisation fails with multiple files

tyktester · August 31, 2018, 1:10pm

I’m trying to use a Python plugin which is divided across several files.

It works fine when there is only one file in the manifest.json. However, when a second file is added, initialisation fails with:

“Middleware initialization error: [Errno 2] No such file or directory: ‘/middleware.py’”.

The bundle has been downloaded and unpacked correctly, and both files are present at:

/opt/tyk-gateway/middleware/bundles/[guid]

I suspect this may be related to 2.7.0 downloaded middleware bundles "no such file or directory" · Issue #1839 · TykTechnologies/tyk · GitHub, which describes a similar bug for JSVM.

Reviewing the source code here:

github.com

TykTechnologies/tyk/blob/dfd77e8e1c5bb271527a7654409027c94bea0eb1/coprocess/python/tyk/middleware.py#L31


      
          self.bundle_root_path = bundle_root_path
          
          
self.imported_modules = []
          
          
module_splits = filepath.split('_')
          self.api_id, self.middleware_id = module_splits[0], module_splits[1]
          
          
self.module_path = os.path.join(self.bundle_root_path, filepath)
          self.parse_manifest()
          
          
self.mw_path = os.path.join(self.module_path, "/middleware.py")
          
          
# Fallback for single file bundles:
          if len(self.manifest['file_list']) == 1:
              self.mw_path = os.path.join(self.module_path, self.manifest['file_list'][0])
          
          
try:
              self.loader = MiddlewareLoader(self)
              sys.meta_path.append(self.loader)
              invalidate_caches()
              self.module = imp.load_source(filepath, self.mw_path)

it seems that this is a bug; that code will always set the path to /middleware.py, as starting with the / creates an absolute path.