On CentOS 7 Snap package upgrades do not work properly, using Wekan Snap

is there some problems running Snaps on CentOS 7 ? It seems that Wekan Snap upgrades do result to non-working Snaps on CentOS. I have not seen this on Ubuntu or Debian.

Report from CentOS user is here:

Thanks for the report. I have installed wekan and then performed an update with a repacked snap, things seem to work fine. I did not observe any problems with mongodb not starting as the user who reported the issue saw.

According to the logs mongodb exist with status 48:

wekan.mongodb[2524]: ATTACHMENTS_STORE_PATH= (default value)
wekan.mongodb[2524]: mongodb bind options:  --bind_ip --port 27019
mongod.27019[3256]: [initandlisten] MongoDB starting : pid=3256 port=27019 dbpath=/var/snap/wekan/common 64-bit host=centos7andy.jhallpr.com
mongod.27019[3256]: [initandlisten] db version v3.2.22
mongod.27019[3256]: [initandlisten] git version: 105acca0d443f9a47c1a5bd608fd7133840a58dd
mongod.27019[3256]: [initandlisten] OpenSSL version: OpenSSL 1.0.2g  1 Mar 2016
mongod.27019[3256]: [initandlisten] allocator: tcmalloc
mongod.27019[3256]: [initandlisten] modules: none
mongod.27019[3256]: [initandlisten] build environment:
mongod.27019[3256]: [initandlisten]     distmod: ubuntu1604
mongod.27019[3256]: [initandlisten]     distarch: x86_64
mongod.27019[3256]: [initandlisten]     target_arch: x86_64
mongod.27019[3256]: [initandlisten] options: { net: { bindIp: "", port: 27019 }, storage: { dbPath: "/var/snap/wekan/common", journal: { enabled: true }, mmapv1: { smallFiles: true } }, systemLog: { destination: "syslog", quiet: true } }
systemd[1]: snap.wekan.mongodb.service: main process exited, code=exited, status=48/n/a

Mongodb documentation on exit codes, 48 means:

48 A newly started mongod or mongos could not start listening for incoming connections, due to an error.

Perhaps there’s something else already listening on the port (another mongo instance?). Running ss -pZl should help debug it further.

If anyone’s interested, more details were posted in the github issue.