LogEvent.client_metadata: Cannot parse certain log lines

[akung0324]

There are certain client metadata log lines (4.2 and earlier) for which logevent.clientmetadata returns nothing.

Expected behavior

Example Log Line:

2020-02-07T12:01:39.677+1100 I NETWORK [conn10] received client metadata from 127.0.0.1:65199 conn: { driver: { name: "mongo-go-driver", version: "v1.1.2" }, os: { type: "darwin", architecture: "amd64" }, platform: "go1.12.9" }

Result of logevent.clientmetadata:

{'driver': {'name': 'mongo-go-driver', 'version': 'v1.1.2'}, 'os': {'type': 'darwin', 'architecture': 'amd64'}, 'platform': 'go1.12.9'}

Actual/current behavior

Example Log Line (impacted by this bug):

2020-02-07T11:59:14.109+1100 I NETWORK [conn1] received client metadata from 127.0.0.1:64766 conn: { driver: { name: "PyMongo", version: "3.10.1" }, os: { type: "Darwin", name: "Darwin", architecture: "x86_64", version: "10.14.6" }, platform: "CPython 3.8.1.final.0", application: { name: "mlaunch v1.6.2-dev" } }

Result of logevent.clientmetadata: None

Steps to reproduce the actual/current behavior

1. Add an option --test to mloginfo for the purpose of this reproduction:

   • Add the attached test_section.py file to the mtools/loginfo/sections folder.
   • Insert a line into the top of mtools/mloginfo/sections/__init__.py that looks like from .test_section import TestSection.

2. Run mloginfo --test on mtools/test/logfiles/sharding_360_mongos.log as an example. All the client metadata log lines that result in logevent.clientmetadata returning nothing are prefixed with "ERROR".

3. Run mloginfo --test on another sample log file (attached) called mongod_4.2.11_clients.log. All the client metadata log lines parse successfully.

Issue

It seems like there's a bug in mtools/util/logevent.py in this part of the code:

    def client_metadata(self):
        """Return client metadata."""
...
                        # Replace double-quoted platform values with single quote
                        platform = re.search(r'"platform"\s+:\s+"(.*)"', metadata)
                        if (platform):
	                    platform = platform.group(1)
                            platform_esc, _ = re.subn(r'"', r"'", platform)
                            metadata, _ = re.subn(platform, platform_esc, metadata)
...

Environment

Software	Version
mtools	1.7.0
Python	3.7.10
Operating system	Amazon Linux 2