Now i see it got failed again. @cdhowie @fd0 --no-lock works only with list locks but not with cat lock as shown below.
fatal: [172.20.32.103]: FAILED! => {"changed": true, "cmd": "/opt/bin/perform-backup.sh",
"delta": "0:00:06.635726", "end": "2019-01-07 23:00:19.653406", "msg": "non-zero return code", "rc": 1,
"start": "2019-01-07 23:00:13.017680",
"stderr": "Fatal: unable to create lock in backend: repository is already locked exclusively by PID 19309 on ip-172-31-254-13.eu-central-1.compute.internal by centos (UID 1000, GID 1000)\n
lock was created at 2019-01-07 12:03:44 (9h56m31.993275421s ago)\n
storage ID eeb53d35\n
Fatal: create key in repository at s3:s3.amazonaws.com/rbmh-mit-backup-ffm-prod-ss-db-barman failed: repository master key and config already initialized\n\n
Fatal: unable to create lock in backend: repository is already locked exclusively by PID 19309 on ip-172-31-254-13.eu-central-1.compute.internal by centos (UID 1000, GID 1000)\n
lock was created at 2019-01-07 12:03:44 (9h56m34.703089764s ago)\n
storage ID eeb53d35",
"stderr_lines": ["Fatal: unable to create lock in backend: repository is already locked exclusively by PID 19309 on ip-172-31-254-13.eu-central-1.compute.internal by centos (UID 1000, GID 1000)",
"lock was created at 2019-01-07 12:03:44 (9h56m31.993275421s ago)",
"storage ID eeb53d35",
"Fatal: create key in repository at s3:s3.amazonaws.com/rbmh-mit-backup-ffm-prod-ss-db-barman failed: repository master key and config already initialized", "",
"Fatal: unable to create lock in backend: repository is already locked exclusively by PID 19309 on ip-172-31-254-13.eu-central-1.compute.internal by centos (UID 1000, GID 1000)",
"lock was created at 2019-01-07 12:03:44 (9h56m34.703089764s ago)",
"storage ID eeb53d35"], "stdout": "\\n
Backup has failed",
"stdout_lines": ["\\nBackup has failed"]}
[admin@prod-db-barman001 ~]$ sudo -E -u restic -- /usr/bin/restic list locks --no-lock
repository 3c742af6 opened successfully, password is correct
eeb53d35a1530ddbec1705d9c0b75eb12ab329f9cb11c46fd9f34008a1245ae3
[admin@prod-db-barman001 ~]$ sudo -E -u restic -- /usr/bin/restic cat lock eeb53d35a1530ddbec1705d9c0b75eb12ab329f9cb11c46fd9f34008a1245ae3 --no-lock
repository 3c742af6 opened successfully, password is correct
Fatal: unable to create lock in backend: repository is already locked exclusively by PID 19309 on ip-172-31-254-13.eu-central-1.compute.internal by centos (UID 1000, GID 1000)
lock was created at 2019-01-07 12:03:44 (16h9m51.202306499s ago)
storage ID eeb53d35
[admin@prod-db-barman001 ~]$