maven_artifact: download with shutil.copyfileobj to a temp file (#44956)

* maven_artifact: replace homemade chunked download with shutil.copyfileobj

* maven_artifact: copy to temp file first

lib/ansible/modules/packaging/language/maven_artifact.py

@@ -158,9 +158,9 @@ EXAMPLES = '''
 import hashlib
 import os
 import posixpath
-import sys
 import shutil
 import io
+import tempfile
 
 try:
     from lxml import etree
@@ -371,56 +371,40 @@ class MavenDownloader:
             raise ValueError(failmsg + " because of " + info['msg'] + "for URL " + url_to_use)
         return None
 
-    def download(self, artifact, verify_download, filename=None):
+    def download(self, tmpdir, artifact, verify_download, filename=None):
-        filename = artifact.get_filename(filename)
         if not artifact.version or artifact.version == "latest":
             artifact = Artifact(artifact.group_id, artifact.artifact_id, self.find_latest_version_available(artifact),
                                 artifact.classifier, artifact.extension)
         url = self.find_uri_for_artifact(artifact)
+        tempfd, tempname = tempfile.mkstemp(dir=tmpdir)
+
+        try:
+            # copy to temp file
             if self.local:
                 parsed_url = urlparse(url)
                 if os.path.isfile(parsed_url.path):
-                shutil.copy2(parsed_url.path, filename)
+                    shutil.copy2(parsed_url.path, tempname)
                 else:
                     return "Can not find local file: " + parsed_url.path
             else:
                 response = self._request(url, "Failed to download artifact " + str(artifact))
-            with io.open(filename, 'wb') as f:
+                with os.fdopen(tempfd, 'wb') as f:
-                self._write_chunks(response, f, report_hook=self.chunk_report)
+                    shutil.copyfileobj(response, f)
+
             if verify_download:
-            invalid_md5 = self.is_invalid_md5(filename, url)
+                invalid_md5 = self.is_invalid_md5(tempname, url)
                 if invalid_md5:
                     # if verify_change was set, the previous file would be deleted
-                os.remove(filename)
+                    os.remove(tempname)
                     return invalid_md5
+        except Exception as e:
+            os.remove(tempname)
+            raise e
+
+        # all good, now copy temp file to target
+        shutil.move(tempname, artifact.get_filename(filename))
         return None
 
-    def chunk_report(self, bytes_so_far, chunk_size, total_size):
-        percent = float(bytes_so_far) / total_size
-        percent = round(percent * 100, 2)
-        sys.stdout.write("Downloaded %d of %d bytes (%0.2f%%)\r" %
-                         (bytes_so_far, total_size, percent))
-        if bytes_so_far >= total_size:
-            sys.stdout.write('\n')
-
-    def _write_chunks(self, response, filehandle, chunk_size=8192, report_hook=None):
-        total_size = response.info().get('Content-Length').strip()
-        total_size = int(total_size)
-        bytes_so_far = 0
-
-        while True:
-            chunk = response.read(chunk_size)
-            bytes_so_far += len(chunk)
-
-            if not chunk:
-                break
-
-            filehandle.write(chunk)
-            if report_hook:
-                report_hook(bytes_so_far, chunk_size, total_size)
-
-        return bytes_so_far
-
     def is_invalid_md5(self, file, remote_url):
         if os.path.exists(file):
             local_md5 = self._local_md5(file)
@@ -546,7 +530,7 @@ def main():
 
     if prev_state == "absent":
         try:
-            download_error = downloader.download(artifact, verify_download, b_dest)
+            download_error = downloader.download(module.tmpdir, artifact, verify_download, b_dest)
             if download_error is None:
                 changed = True
             else: