Add ability to specify log format

[mminer]

It would be helpful to have control over the format of the log output. For inspiration, other tools that allow you to customize the log format include Celery (CELERYD_LOG_FORMAT) and Gunicorn (access_log_format).

[oponcea-dn]

+1

[sscarduzio]

This should be added as a core feature in supervisord, it's not a job for weird wrapper scripts.

[j0wns]

For ones who are looking for some workaround. Here is how I ended with prefixing output with process name:

supervisor.conf

[program:process-1]
command=/path-to/prefix-output.sh executable1

[program:process-2]
command=/path-to/prefix-output.sh executable2

prefix-output.sh

#!/bin/bash

# Get prefix from SUPERVISOR_PROCESS_NAME environment variable
printf -v PREFIX "%-10.10s" "${SUPERVISOR_PROCESS_NAME}"

# Prefix stdout and stderr
exec 1> >( perl -ne '$| = 1; print "'"${PREFIX}"' | $_"' >&1)
exec 2> >( perl -ne '$| = 1; print "'"${PREFIX}"' | $_"' >&2)

exec "$@"

Example output

process-1  | Some process output
process-2  | Very important message
...

Inspired and mostly copy-pasted from: https://serverfault.com/a/946271

This was an excellent starting point for adding a static name to subprocess output.

I wanted improve the consistency for readability and parsing by adding per-line time stamps that matched supervisord's format: '2023-06-09 17:25:36,778 INFO Included extra file "/etc/supervisor/conf.d/example.conf" during parsing'

This perl in the following heredoc will calculate a timestamp at run time for each line that is sent to stdout and stderr

# https://github.com/Supervisor/supervisor/issues/553
# Refer: https://stackoverflow.com/questions/26032541/how-to-get-system-time-in-nano-seconds-in-perl
cat << 'EOF' > /opt/supervisord/prefix-output.sh
#!/bin/bash

# Prefix outputs with Time Stamp and Process Name
exec 1> >( perl -ne 'use Time::HiRes qw(time); use POSIX qw( strftime ); $time=time; $microsecs = ($time - int($time)) * 1e3; $| = 1; printf( "%s,%03.0f '"${SUPERVISOR_PROCESS_NAME}"' %s", strftime("%Y-%m-%d %H:%M:%S", gmtime($time)), $microsecs, $_);' >&1)
exec 2> >( perl -ne 'use Time::HiRes qw(time); use POSIX qw( strftime ); $time=time; $microsecs = ($time - int($time)) * 1e3; $| = 1; printf( "%s,%03.0f '"${SUPERVISOR_PROCESS_NAME}"' %s", strftime("%Y-%m-%d %H:%M:%S", gmtime($time)), $microsecs, $_);' >&2)

exec "$@"
EOF

Example Output running within a docker container

container  | 2023-06-09 17:39:30,474 INFO spawned: 'env' with pid 61
container  | 2023-06-09 17:39:30,474 INFO success: env entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)
container  | 2023-06-09 17:39:30,507 env SUPERVISOR_GROUP_NAME=init
container  | 2023-06-09 17:39:30,507 env SUPERVISOR_SERVER_URL=unix:///var/run/supervisor.sock

[kadirgun]

+1

[mrtzgh]

+1

[CRCinAU]

+1

[Pre-Z]

+1

[RDonii]

+1