ex2.md

Build a system with NScale

This tutorial covers:

1. Creating a new system
2. Hooking up a new container definition
3. Building a new container
4. Run!

Create a new System

A system is just a git repository, like the one you cloned in the previous step. That system definition contains everything nscale needs to know to deploy your application.

Let's go ahead and create a new system with:

$ nsd sys create
prompt: name:  workshop
prompt: namespace:  nscale
create system: workshop with namespace: nscale?
prompt: confirm (y/n):  y
ok

Now we can check that everything is as expected:

$ nsd sys list
Name                           Id
workshop                       521a3a73-7d5d-434d-96c5-e4732db307be

(In nscale, you can shorten commands down to 3 chars.)

The list command will return any systems that nsd is aware of, including our new nscale_workshop system:

The nsd sys create creates a new git repository in the current directory. Go ahead and have a look at the files in there.

There are three files:

1. deployed.json contains the currently deployed system.
2. system.json contains the system definition, all the containers and how to build them.
3. timeline.json contains all the events that happened in the system.

Preparing the Application

Containers should live in a git repository, this allows nscale to check out the repo and build the containers for us.

Let's take the example we built in exercise 1, and place it in a git repository on github.

We'll also include an bash script in our new repo, that can customize how the container will be built. In our case, this is really simple:

#!/bin/bash

echo TARGET:.

We'll name this build.sh

Now we can build multiple containers from the same git repository.

In this tutorial, our test repo will be: [email protected]:nearform/nscale-workshop-intro-docker-sample.git

Add a container definition

Let's open system.json in you favorite editor. It looks like this:

{
  "name": "workshop",
  "namespace": "nscale",
  "id": "521a3a73-7d5d-434d-96c5-e4732db307be",
  "containerDefinitions": [
  ],
  "topology": {
    "containers": {}
  }
}

To begin creating a system, we need to add the container definitions:

{
  // the other stuff
  "containerDefinitions": [
    {
      "name": "Machine",
      "type": "virtualbox",
      "specific": {
        "repositoryToken": "04551b154404a852e663aba4c3fa299e04f6e8a5"
      },
      "id": "85d99b2c-06d0-5485-9501-4d4ed429799c"
    },
    {
      "name": "web",
      "type": "boot2docker",
      "dependencies": {},
      "specific": {
        "repositoryUrl": "[email protected]:nearform/nscale-workshop-intro-docker-sample.git",
        "buildScript": "build.sh",
        "arguments": "-p 1337:1337 -d __TARGETNAME__"
      },
      "id": "9ddc6c027-9ce2-5fdg-9936-696d2b3789bb",
      "version": "0.0.1"
    }
  ]
  // other stuff
}

Build a container

In order to build a container, we need to initialize our topology section:

{
  // other stuff
  "topology": {
    "containers": {
      "10": {
        "id": "10",
        "containerDefinitionId": "85d99b2c-06d0-5485-9501-4d4ed429799c",
        "containedBy": "10",
        "contains": [
          "8bd49b5b-3bd9-4314-8895-a2ec26e28175"
        ],
        "specific": {
          "ipaddress": "localhost"
        }
      },
      "8bd49b5b-3bd9-4314-8895-a2ec26e28175": {
        "id": "8bd49b5b-3bd9-4314-8895-a2ec26e28175",
        "containerDefinitionId": "9ddc6c027-9ce2-5fdg-9936-696d2b3789bb",
        "containedBy": "10",
        "contains": [],
        "specific": {
          "dockerLocalTag": "nfddemo/web-1",
          "version": "0.0.1"
        }
      }
    }
  }
}

Finally for nscale to be aware of our new containers, we create a new git commit in the system git repo.

$ git commit -a -m 'new containers'

Let's check if nscale detected the changes:

$ nsd rev list workshop
revision             deployed who                                                     time                      description
6cd3208029943c209a5… false    Matteo Collina <[email protected]>               2014-09-08T22:03:06.000Z  Updated container definition.
f398e76c26114173a18… false    Matteo Collina <[email protected]>               2014-09-08T21:45:22.000Z  first commit
revision             deployed who                                                     time                      description
6cd3208029943c209a5… false    Matteo Collina <[email protected]>               2014-09-08T22:03:06.000Z  Updated container definition.
f398e76c26114173a18… false    Matteo Collina <[email protected]>               2014-09-08T21:45:22.000Z  first commit

Now, let's buid our containers:

$ nsd container build workshop web

We'll check the revision list again:

$ nsd rev list workshop
revision             deployed who                                                     time                      description
8735764f9e57b9838b1… false    Matteo Collina <[email protected]>               2014-09-08T22:08:11.000Z  built container: cf28904e57b0c4b84b24d0297820e8a6…
6cd3208029943c209a5… false    Matteo Collina <[email protected]>               2014-09-08T22:03:06.000Z  Updated container definition.
f398e76c26114173a18… false    Matteo Collina <[email protected]>               2014-09-08T21:45:22.000Z  first commit

Deploy

All we have to do now is deploy:

$ nsd rev deploy workshop 8735

The 8735 part is just the first chars of the revision identifier from nsd rev list

Our container should be running just fine, we can use the following to see it in action:

OS X :

$ curl http://$(boot2docker ip):1337

Linux:

$ curl http://localhost:1337

Next up: exercise 3