<4>Apr  8 14:13:38 postgres kernel: [773298.077731] [UFW BLOCK] IN=ens5 OUT= MAC=02:87:d6:fb:4c:36:02:4b:94:bf:cd:44:08:00 SRC=140.201.193.135 DST=75.150.42.82 LEN=60 TOS=0x00 PREC=0x00 TTL=40 ID=6132 DF PROTO=TCP SPT=37379 DPT=5432 WINDOW=35844 RES=0x00 SYN URGP=0 
This is a syslog message from a product called Uncomplicated Firewall (UFW) by linux. The following fields were extracted from the message:
action: block
clientport: 37379
facilitylabel: kernel
localhostname: postgres
localstarttime: Apr  8 14:13:38
messagetype: firewall_action
priority: 4
program: kernel
protocol: 6
senderhost: 10.1.100.194
sensitivity: normal
serverbytes: 60
serverport: 5432
severitycode: 4
severitylabel: warning
sourceinfo: unknown
tags: ['rfc3164', 'ufw', 'firewall_action']
streamName: ufw
clientIP: 140.201.193.135
serverIP: 75.150.42.82