Eremetic is a Mesos Framework to run one-shot tasks.

Usage

Send a cURL to the eremetic framework with how much cpu and memory you need, what docker image to run and which command to run with that image.

curl -H "Content-Type: application/json" \
     -X POST \
     -d '{"task_mem":22.0, "task_cpus":1.0, "docker_image": "a_docker_container", "command": "rails"}' \
     http://eremetic_server:8080/task

These basic fields are required but you can also specify volumes, environment variables, and URIs for the mesos fetcher to download. See examples.md for more examples on how to use eremetic.

JSON format:

{
  // Float64, fractions of a CPU to request
  "task_cpus":      1.0,
  // Float64, memory to use (MiB)
  "task_mem":       22.0,
  // String, full tag or hash of container to run
  "docker_image":   "busybox",
  // String, command to run in the docker container
  "command": "echo date",
  // Array of Objects, volumes to mount in the container
  "volumes": [
    {
      "container_path": "/var/run/docker.sock",
      "host_path": "/var/run/docker.sock"
    }
  ],
  // Object, Environment variables to pass to the container
  "env": {
    "KEY": "value"
  },
  // Object, Will be merged to `env` when passed to Mesos, but masked when doing a GET.
  // See Clarification of the Masked Env field below for more information
  "masked_env": {
    "KEY": "value"
  },
  // URIs of resource to download
  "uris": [
    "http://server.local/resource"
  ],
  // String, URL to post a callback to. Callback message has format:
  // {"time":1451398320,"status":"TASK_FAILED","task_id":"eremetic-task.79feb50d-3d36-47cf-98ff-a52ef2bc0eb5"}
  "callback_uri": "http://callback.local"
}

Note

Most of this meta-data will not remain after a full restart of Eremetic.

Clarification of the Masked Env field

The purpose of the field is to provide a way to pass along environment variables that you don't want to have exposed in a subsequent GET call. It is not intended to provide full security, as someone with access to either the machine running Eremetic or the Mesos Slave that the task is being run on will still be able to view these values. These values are not encrypted, but simply masked when retrieved back via the API.

For security purposes, ensure TLS (https) is being used for the Eremetic communication and that access to any machines is properly restricted.

Configuration

create /etc/eremetic/eremetic.yml with:

address: 0.0.0.0
port: 8080
master: zk://<zookeeper_node1:port>,<zookeeper_node2:port>,(...)/mesos
messenger_address: <callback address for mesos>
messenger_port: <port for mesos to communicate on>
loglevel: DEBUG
logformat: json

Authentication

To enable mesos framework authentication add the location of credential file to your configuration:

credential_file: /var/mesos_secret

The file should contain the Principal to authenticate and the secret separated by white space like so:

principal    secret_key

Building

Environment

Clone the repository into $GOCODE/src/github.com/klarna/eremetic. This is needed because of internal package dependencies

Install dependencies

First you need to install dependencies. Parts of the eremetic code is auto-generated (assets and templates for the HTML view are compiled). In order for go generate to work, go-bindata and go-bindata-assetfs needs to be manually installed.

go get github.com/jteeuwen/go-bindata/...
go get github.com/elazarl/go-bindata-assetfs/...
go generate
go get -t ./...

Creating the docker image

To build a docker image with eremetic, simply run

make docker

Running on mesos

Eremetic can itself by run on mesos using e.g marathon. An example configuration for marathon is provided that is ready to be submitted through the api.

curl -X POST -H 'Content-Type: application/json' $MARATHON/v2/apps -d@misc/eremetic.json

Running tests

The tests rely on GoConvey, and can be run either by running goconvey or go test ./... from the project root.

Contributors

• Rickard Dybeck
• David Keijser
• Aidan McGinley

Acknowledgements

Thanks to Sebastian Norde for the awesome logo!

Licensing

Apache-2