mhausenblas/ntil repository overview

⁠ntil

This is a DCOS demo app, a simple event counter that watches out for a topic on Twitter as well.

⁠Deployments

In all scenarios below, we will use Marathon⁠ to deploy the ntil app. Also note that I'm using HTTPie⁠ here in the example, but you can achieve similar results using curl. All deployments are based on the Docker image mhausenblas/ntil⁠.

In order for the Twitter watch part to work you'll need to supply your Twitter credentials. You can obtain those from creating a Twitter application via apps.twitter.com⁠.

⁠Playa Mesos

Ramp up your playa-mesos⁠ sandbox, log in and get the ntil app:

$ vagrant up
$ vagrant ssh
$ git clone https://github.com/mhausenblas/ntil.git
$ cd ntil

If you do a Docker deployment on Marathon the first time, now would be a good time to read Running Docker Containers on Marathon⁠. In a nutshell: make sure Docker is installed and containerizer enabled.

You can test ntil in Docker directly, inside the Playa sandbox, using docker run -d mhausenblas/ntil:latest and once the container is launched—you may want to check with docker ps (and docker kill/docker rm respectively afterwards)—you should be able to access the app through pointing your browser to http://localhost:9889/⁠ where the UI is or via the following API commands:

$ http http://localhost:9889/service/target
$ http http://localhost:9889/service/topic

Now you're ready to deploy ntil via the Marathon HTTP API, again using the same Docker image from above:

$ http POST http://10.141.141.10:8080/v2/apps < ntil-app-playa.json
$ http GET http://10.141.141.10:8080/v2/apps/ntil
$ http DELETE http://10.141.141.10:8080/v2/apps/ntil

Note that in order for the Twitter watch integration to work, you will have to provide your own Twitter credentials by editing ntil-app-playa.json:

$ cat ntil-app-playa.json
{
    "id": "ntil",
    "instances": 1,
    "cpus": 1,
    "mem": 100,
    "container": {
        "type": "DOCKER",
        "docker": {
            "image": "mhausenblas/ntil:latest"
        }
    },
    "args": ["-e", "2015-04-28T17:00:00", "-t", "mesos", "-k", "10ad9...", "-s", "a2cd...", "-a", "0ghs...", "-o", "hf95..." ]
}

Using the following parameters from your app definition at apps.twitter.com⁠:

• -k ... Consumer Key (API Key)
• -s ... Consumer Secret (API Secret)
• -a ... Access Token
• -o ... Access Token Secret

Another note concerning the build process (which should not effect you in normal operation): I sometimes had issues (cache? GC? timeout?) with the Docker image not being up-to-date. The following helped (inside the Playa sandbox):

$ docker pull
$ sudo stop mesos-slave
$ sudo start mesos-slave

⁠AWS

I assume that you have the DCOS⁠ EA or PB version installed, which comes with Marathon pre-installed.

So now it's time to log into a cluster instance and install and deploy ntil:

$ ssh -i ~/.ssh/mesosphere.pem [email protected]
$ git clone https://github.com/mhausenblas/ntil.git
$ cd ntil
$ alias http='docker run -i --rm --net=host clue/httpie'
$ cp ntil-app-aws.json my-ntil-app-aws.json
$ vi my-ntil-app-aws.json # edit to include your Twitter credentials
$ http POST http://ec2-52-17-39-227.eu-west-1.compute.amazonaws.com:8080/v2/apps < my-ntil-app-aws.json

Now, have a look in the Marathon UI:

In my case, Mesos has placed the app on instance ec2-52-17-218-139.eu-west-1.compute.amazonaws.com (ignore the randomly assigned port 10000). Use the FQDN you find here and replace the port with 9889 (ntils default service port) and you're done: