docker-logger

docker-logger is a small application collecting logs from other containers on the host that started without the -t option and configured with a logging driver that works with docker logs (journald and json-file). It can forward both stdout and stderr of containers to local, rotated files and/or to remote syslog.

note: dkll inlcudes all functionality of docker-logger, but adds server and cli client

Install

Copy provided docker-compose.yml, customize if needed and run with docker-compose up -d. By default docker-logger will collect all logs from containers and put it to ./logs directory.

Customization

All changes can be done via container's environment in docker-compose.yml or with command line

Command line	Environment	Default	Description
--docker	DOCKER_HOST	unix:///var/run/docker.sock	docker host
--syslog-host	SYSLOG_HOST	127.0.0.1:514	syslog remote host (udp4)
--files	LOG_FILES	No	enable logging to files
--syslog	LOG_SYSLOG	No	enable logging to syslog
--max-size	MAX_SIZE	10	size of log triggering rotation (MB)
--max-files	MAX_FILES	5	number of rotated files to retain
--mix-err	MIX_ERR	false	send error to std output log file
--max-age	MAX_AGE	30	maximum number of days to retain
--exclude	EXCLUDE		excluded container names, comma separated
--include	INCLUDE		only included container names, comma separated
--include-pattern	INCLUDE_PATTERN		only include container names matching a regex
	TIME_ZONE	UTC	time zone for container
--json, -j	JSON	false	output formatted as JSON

• at least one of destinations (files or syslog) should be allowed
• location of log files can be mapped to host via volume, ex: - ./logs:/srv/logs (see docker-compose.yml)
• both --exclude and --include flags are optional and mutually exclusive, i.e. if --exclude defined --include not allowed, and vise versa.
• both --include and --include-pattern flags are optional and mutually exclusive, i.e. if --include defined --include-pattern not allowed, and vise versa.

Build from the source

• clone this repo - git clone https://github.com/umputun/docker-logger.git
• build the logger - cd docker-logger && docker build -t umputun/docker-logger .
• try it - docker run -it --rm -v $(pwd)/logs:/srv/logs -v /var/run/docker.sock:/var/run/docker.sock umputun/docker-logger /srv/docker-logger --files