Preparing the system for alerts

We'll deploy the stack defined in stacks/jenkins.yml (https://github.com/vfarcic/docker-flow-monitor/blob/master/stacks/jenkins.yml). The definition is as follows.

version: '3.1'

services:

  master:
image: vfarcic/jenkins
ports:
- 50000:50000
environment:
- JENKINS_OPTS="--prefix=/jenkins"
networks:
- proxy
- default
deploy:
labels:
- com.df.notify=true
- com.df.distribute=true
- com.df.servicePath=/jenkins
- com.df.port=8080
extra_hosts:
- "${SLACK_HOST:-devops20.slack.com}:${SLACK_IP:-54.192.78.227}"
secrets:
- jenkins-user
- jenkins-pass

agent:
image: vfarcic/jenkins-swarm-agent
environment:
- USER_NAME_SECRET=/run/secrets/${JENKINS_USER_SECRET:-\
jenkins-user}
- PASSWORD_SECRET=/run/secrets/${JENKINS_PASS_SECRET:-\
jenkins-pass}
- COMMAND_OPTIONS=-master http://master:8080/jenkins -labels\
 'prod' -executors 4
networks:
- default
volumes:
- /var/run/docker.sock:/var/run/docker.sock
secrets:
    - jenkins-user
- jenkins-pass
deploy:
placement:
constraints...