Docker Syslog
*More Videos For Docker Syslog »*Docker Syslog-addressScenarioWhile using a syslog driver with TCP or TLS is a reliable method for the delivery of logs, temporary network issues or high network latency can interrupt real-time monitoring. It’s seen often when the syslog server is unreachable, Docker Syslog driver blocks the deployment of containers and also loses logs.You have Docker installed and want to send your Docker logs (default is json-file) to a local syslog facility (i.e. local6).You can use the --log-driver=VALUE with the docker run command to configure the container’s logging driver or you can set the parameter globally in the docker daemon configuration file. This is useful when using container orchestration such as Kubernetes or Apache Mesos.Step #1Edit the docker configuration file (/etc/sysconfig/docker on RHEL/CentOS based systems).*Docker Syslog Setup. Start the Loggly Docker Container. Run the following command to download and run the Loggly docker container. The rsyslog daemon is running inside this container and will send syslog to Loggly. This will also open a high numbered port on the host machine, which maps to port 514 inside the container where rsyslog will.*Connect Syslog Docker. Syslog lets you monitor and review device logs across your entire infrastructure. StrongDM uses standardized messaging protocols like Syslog to send access and session logs from Docker containers to your logging tools. Free 14-day trial, no credit card required.Add the log driver parameter (--log-driver=syslog --log-opt syslog-facility=local6 --log-level=warn) to the OPTIONS line.Restart the docker daemon.Step #2Configure the syslog daemon to listen on local6 and write logs to specified location.Create a new file in /etc/rsyslog.d called docker.conf.Add the following line to the /etc/rsyslog.d/docker.conf file.Make sure that /var/log/docker exists.Restart the rsyslog daemonStart a Docker container or two. You will be now able to view all Docker logs in /var/log/docker/docker.log.For additional information on configuring Dockers logging drivers, please visit https-//docs.docker.com/engine/admin/logging/overview.My objective is to get logging output from my container applications consolidated under /var/log, with logfile names matching their origin container. Logfile cohabitation will allow me to incorporate them in the housekeeping rotation ritual of the rest of my system, and help with speedy fault diagnosis.The environment- Traefik v1, Docker, Docker-Compose, Nginx, Ubuntu 18.04, rsyslogd, logrotate. This is a basic setup presenting the Welcome to nginx! page.Some Docker logging basicsWith some standard containers running, some simple logging can be seen using the docker logs command at the prompt, specifying a container name. Here we just see a bunch of simple HTTP 200 responses for the Nginx basic Welcome to nginx!.I am using a very basic Docker config with docker-compose serving up Traefik and Nginx containers, with the default Welcome screen.Configuring a Syslog catcher for custom log filesFor maximum flexibility, I would like to be able to specify a tag in the compose definition that determines the eventual log file name, and I would like to group all of the container based application logs under a new directory, /var/log/containers. A subdirectory is optional.In /etc/rsyslog.d I create a new template file, the name is arbitrary, here 40-docker.conf, but check the below text about duplicates when naming. With your favourite text editor add the contents-I will prefix any container logs with the string docker- for filtering and grouping purposes. Run the following, if you are going to also use a logging subdirectory strategy-Restart rsyslogd with sudo systemctl restart rsyslog (Ubuntu 18.04).About duplicate log file entriesSyslog will read the files in /etc/rsyslog.d in order. Our sample .conf file has a tilde at the end, which indicates a stop to further processing. Therefore, if you create a .conf file such as 40-docker.conf that is processed before the 50-default.conf file, it will be logged to the appropriate custom container log, then processing for that entry will stop.If you create a .conf file such as 60-docker.conf it will be processed after the 50-default.conf, so the entry will first be logged in the main default syslog, then in the custom docker file. You will end up with the same entry in both places.Setting up Docker Compose for the loggingI want to use the syslog format, so my logging entry in the