Modify elastic beanstalk default log output prefix

elastic-beanstalk-log-prefix.md

By default elastic beanstalk logs are prefixed by the date and the ip. This is may not be desired, either because the date is also in the logs or because the timestamp is included in cloudwatch logs metadata.

We can remove it by adding two hooks (both with the same content):

• .platform/hooks/predeploy/10_logs.sh
• .platform/confighooks/predeploy/10_logs.sh

Note: You must ensure these are executable before packaing (chmod +x).

#!/bin/sh
# By default logs output to /var/log/web.stdout.log are prefixed.
# We want just the raw logs from the app...
# This updates the rsyslog config (to use the WebTemplate format).
# Also grants read permissions to the log files.

# This file is duplicated here:
# .platform/hooks/predeploy/10_logs.sh
# .platform/confighooks/predeploy/10_logs.sh

set -eu

echo '
# This file is created from Elastic Beanstalk platform hooks.
template(name="WebTemplate" type="string" string="%msg%\n")

if \$programname == "web" then {
  *.=warning;*.=err;*.=crit;*.=alert;*.=emerg; /var/log/web.stderr.log;WebTemplate
  *.=info;*.=notice /var/log/web.stdout.log;WebTemplate
}
' > /etc/rsyslog.d/web.conf

touch /var/log/web.stdout.log
touch /var/log/web.stderr.log
chmod +r /var/log/web.stdout.log
chmod +r /var/log/web.stderr.log

systemctl restart rsyslog.service

This is a modification of yo1dog's serverfault answer.