docker_login: Use with statement for accessing files (#64382) (#64392)

* docker_login: Use with statement for accessing files (#64382)

* Update changelogs/fragments/64382-docker_login-fix-invalid-json.yml

Co-Authored-By: Felix Fontein <felix@fontein.de>

changelogs/fragments/64382-docker_login-fix-invalid-json.yml

@@ -0,0 +1,2 @@
+bugfixes:
+- "docker_login - Use ``with`` statement when accessing files, to prevent that invalid JSON output is produced."

lib/ansible/modules/cloud/docker/docker_login.py

@@ -259,7 +259,8 @@ class LoginManager(DockerBaseClass):
 
     def write_config(self, path, config):
         try:
-            json.dump(config, open(path, "w"), indent=5, sort_keys=True)
+            with open(path, "w") as file:
+                json.dump(config, file, indent=5, sort_keys=True)
         except Exception as exc:
             self.fail("Error: failed to write config to %s - %s" % (path, str(exc)))
 
@@ -277,7 +278,8 @@ class LoginManager(DockerBaseClass):
 
         try:
             # read the existing config
-            config = json.load(open(path, "r"))
+            with open(path, "r") as file:
+                config = json.load(file)
         except ValueError:
             self.log("Error reading config from %s" % (path))
             config = dict()