Docker Cookbook

220 | Chapter 7: The Docker Ecosystem: Tools

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Figure 7-8. Marathon UI for HTTP server
Let’s now move on to starting an application that is made of a Docker container. By
default, the VM started by Playa Mesos will contain Docker, but the Mesos slave is
not configured to use it. Therefore, you need to do a few configurations and restart
mesos-slave
. In the virtual machine, do the following:
vagrant@mesos:~$ sudo su
root@mesos:/home/vagrant# cd /etc/mesos-slave
root@mesos:/etc/mesos-slave# echo 'docker,mesos' > containerizers
root@mesos:/etc/mesos-salve# echo '5mins' > executor_registration_timeout
root@mesos:/etc/mesos-slave# service mesos-slave restart
mesos-slave stop/waiting
mesos-slave start/running, process 2581
Create the following JSON file (e.g., 
docker.json
) that describes running an Nginx
container with a dynamic port allocation on the host:
{
"container"
:
{
"type"
:
"DOCKER"
,
"docker"
:
{
"image"
:
"nginx"
,
"network"
:
"BRIDGE"
,
"portMappings"
:
[
{
"containerPort"
:
80
,
"hostPort"
:
0
}
]
}
},
"id"
:
"nginx"
,
"instances"
:
1
,
"cpus"
:
0.5
,
"mem"
:
512
}
Create this application via the Marathon API by using 
curl
and check the list of run‐
ning applications:
7.11 Running Containers via Apache Mesos and Marathon | 221

---

$ curl -si -H 'Content-Type: application/json'
-d @docker.json 10.141.141.10:8080/v2/apps
$ curl -sX GET -H "Content-Type: application/json" 10.141.141.10:8080/v2/tasks
| python -m json.tool
{