Spring boot docker mount shared logback config files

Question

I have a spring boot application with a micro services architecture. With something like 10 spring boot containers running.

The setup for loading the logback.xml that I am aiming to do is looks something like this.

How do I mount and load the logback.xml on a spring boot embedded jar / container when I start the containers up.

My thoughts are something like this.

This will run the spring boot app ok.

docker run -d --name=app1 app_image

Something like this is what I am looking to implement load the logback.xml

docker run -d --name=app1 --volume=/home/host-path/log-back-conig-dir/:/container-app-dir/ app_image

docker run -d --name=app2 --volume=/home/host-path/log-back-conig-dir/:/container-app-dir/ app_image

docker run -d --name=app3 --volume=/home/host-path/log-back-conig-dir:/container-app-dir/

Further info

I am using the Dockerfile example taken from the official spring boot

spring.io/guides/gs/spring-boot-docker

Dockerfile

FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG JAR_FILE
ADD ${JAR_FILE} app.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]

logback.xml looks like this

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

    <springProperty scope="context" name="springAppName" source="spring.application.name"/>
    <include resource="org/springframework/boot/logging/logback/base.xml" />

    <springProfile name="default,dev,staging">
        <logger name="guru.springframework.controllers" level="DEBUG" additivity="false">
            <appender-ref ref="CONSOLE" />
        </logger>
    </springProfile>

    <springProfile name="dev">
        <appender name="stash" class="ch.qos.logback.core.rolling.RollingFileAppender">
            <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
                <level>info</level>
            </filter>
            <file>/varlog/log-tracing-demo/build/logs/${springAppName}.log</file>
            <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
                <fileNamePattern>/var/log/log-tracing-demo/build/logs/${springAppName}.log.%d{yyyy-MM-dd}</fileNamePattern>
                <maxHistory>30</maxHistory>
            </rollingPolicy>
            <encoder class="net.logstash.logback.encoder.LogstashEncoder" >
                <includeContext>false</includeContext>
                <fieldNames>
                    <message>msg</message>
                </fieldNames>
                <customFields>{"application_name":"${springAppName}"}</customFields>
            </encoder>
        </appender>
        <root level="info">
            <appender-ref ref="CONSOLE" />
            <appender-ref ref="stash" />
        </root>
    </springProfile>
</configuration>

Short version of question is..

How do make multiple spring boot docker containers to mount and share the same single logback.xml file.

You can add the logback.xml to your Dockerfile and have all your apps use the same config file. However, Docker already produces logs. So it might be a good idea to log spring apps to STDOUT and use something like ELK stack to gather all your logs to one place. — Urosh T., Nov 24 '17 at 15:16
I want to keep the STDOUT as human readable and not json. The ones output to the file are in json format... json format means I do not have to write grok parsers and is less brittle to change. — Robbo_UK, Nov 24 '17 at 15:18
Alternatively , You can create logback.xml as lib project and upload to private artifactory and add dependency on app project. — Panup Pong, Nov 25 '17 at 04:00

score 0 · Answer 1 · answered Nov 24 '17 at 19:41

I would suggest to place logback.xml file in your images using Dockerfile command:

ADD logback.xml container-app-dir/

If you don't want to place your xml config in Dockerfile/image you can use named volume shared across all containers, here is nice info: Docker Compose - Share named volume between multiple containers So you can donwload this config for example in runtime (by making wget) and place into shared named volume.

Spring boot docker mount shared logback config files

1 Answers1