Dcos Series Part 2 Deploy Simple Applications

There are so many interesting things in DC/OS GUI (Dashboard with useful metrics/status from all nodes, Services tab help us to know which application/service is running on which node, its status, etc.).

In this article, we will try to deploy applications to DC/OS and run it.

Universe packages

The Universe tab shows all of the available DC/OS services from package repositories. You can install packages from the DC/OS Universe with a single click. The packages can be installed with defaults or customized directly in the web interface

DC/OS CLI

You also can use the DC/OS command-line interface (CLI) to manage your cluster nodes, install DC/OS packages, inspect the cluster state, and administer the DC/OS service subcommands, deploy application, etc.

Installing

You can quickly install the CLI from the DC/OS web interface.

1. Click Install CLI from the top-left corner of the DC/OS web interface

2. Copy and paste the code snippets into your terminal.

Usage

To list available commands, either run dcos with no parameters or run dcos help

Command line utility for the Mesosphere Datacenter Operating
System (DC/OS). The Mesosphere DC/OS is a distributed operating
system built around Apache Mesos. This utility provides tools
for easy management of a DC/OS installation.

Available DC/OS commands:

    auth               Authenticate to DC/OS cluster
    config             Manage the DC/OS configuration file
    experimental       Experimental commands. These commands are under development and are subject to change
    help               Display help information about DC/OS
    job                Deploy and manage jobs in DC/OS
    marathon           Deploy and manage applications to DC/OS
    node               Administer and manage DC/OS cluster nodes
    package            Install and manage DC/OS software packages
    service            Manage DC/OS services
    task               Manage DC/OS tasks

Get detailed command description with 'dcos <command> --help'.

OK. We will focus on command dcos marathon app add <app-resource>which help us deploy application to DC/OS

Deploy a simple app

1. Create an app definition file named my-app.json with these contents

{
    "id": "/nginx",
    "instances": 1,
    "cpus": 0.1,
    "mem": 64,
    "container": {
    "type": "DOCKER",
    "docker": {
          "image": "nginx",
          "network": "BRIDGE",
          "portMappings": [
            {"containerPort": 80}
          ]
        }
    }
}

Note By default, applications will be deployed to private node, so if you want to deploy to public node, you can add "acceptedResourceRoles": ["slave_public"] to my-app.json

2. Add your app to Marathon:

$ dcos marathon app add <my-app.json>

If this is added successfully, output will be something like this:

Created deployment d562b50a-17b0-44ce-b7d2-02a0c3cc799e

3. Verify that the app is added with this command:

$ dcos marathon app list

The output can be look like this:

ID      MEM  CPUS  TASKS  HEALTH  DEPLOYMENT  CONTAINER  CMD
/nginx   64  0.1    0/1    ---      scale       DOCKER   None

4. Check application on DC/OS GUI

Click on Services tab, you will see list of applications that you are running. To check application’s information, just click on service and choose service ID that you want to see

As the picture above, you can check your application directly via Endpoint