Container support

A Guide To Cloudify Docker Container Support

Overview

Cloudify supports integrations with Docker and Docker-based container managers, including Docker, Docker Swarm, Docker Compose, Kubernetes, and Apache Mesos. At a minimum, Cloudify supports the creation, scaling, and healing of the platforms themselves. For Kubernetes and Docker Swarm, service orchestration is also supported. When orchestrating other orchestrators (e.g. Kubernetes, Swarm, Mesos), the Cloudify philosophy is to lightly integrate so that native descriptors can be used if desired. Options are also provided to use TOSCA based configuration for services, but support is more limited than native descriptors.

Docker Plugin

The Docker plugin is a Cloudify plugin that defines a single type: cloudify.docker.Container. The plugin is compatible with Docker 1.0 (API version 1.12) and relies on the docker-py library. The plugin executes on a computer host that has Docker pre-installed.

Types

cloudify.docker.Container

Properties:

• image A dict describing a docker image. To import an image from a tarball use the src key. The value will be an absolute path or URL. If pulling an image from docker hub, do not use src. The key is repository. The value is that repository name. You may additionally specify the tag, if none is given, latest is assumed.
• name The name of the Docker container. This will also be the host name in Docker host config.
• use_external_resource Boolean indicating whether the container already exists or not.

Interfaces:

The cloudify.interfaces.lifecycle interface is implemented, and supports the following function parameters

• create inputs:
• params A dict of parameters allowed by docker-py to the create_container function
• start inputs:
• params A dictionary of parameters allowed by docker-py to the start function
• processes_to_wait_for A list of processes to verify are active on the container before completing the start operation. If all processes are not active the function will be retried.
• retry_interval Before finishing start checks to see that all processes on the container a A dictionary of parameters allowed by docker-py to the stop function.re ready. This is the interval between checks.
• stop inputs:
• params A dictionary of parameters allowed by docker-py to the stop function.
• retry_interval If Exited is not in the container status, then the plugin will retry. This is the number of seconds between retries.
• delete inputs:
• params A dictionary of parameters allowed by docker-py to the remove_container function.

Docker Swarm Blueprint

The Docker Swarm blueprint creates and manages a Docker Swarm cluster on Openstack. There are 3 blueprints, with slightly different use cases:

• swarm-local-blueprint.yaml : a cfy local blueprint that orchestrates setup and teardown of the cluster without a manager
• swarm-openstack-blueprint.yaml : an Openstack blueprint that orchestrates setup and teardown of the cluster with a manager
• swarm-scale-blueprint.yaml : an Openstack blueprint that orchestrates setup, teardown, autohealing, and autoscaling of the cluster

Prerequisites

These blueprints have only been tested against an Ubuntu 14.04 image with 2GB of RAM. The image used must be pre-installed with Docker 1.12. Any image used should have passwordless ssh, and passwordless sudo with requiretty false or commented out in sudoers. Also required is an Openstack cloud environment. The blueprints were tested on Openstack Kilo.

Usage

swarm-local-blueprint.yaml

Overview

The swarm-local blueprint is intended to be run using the cfy local CLI command. As such, no manager is necessary. The blueprint starts a two node Swarm cluster and related networking infrastructure in Openstack.

Inputs

• image The Openstack image id. This image will be used for both master and worker nodes. This image must be prepared with Docker 1.12, as well as support passwordless ssh, passwordless sudo, and passwordless sudo over ssh. Only Ubuntu 14.04 images have been tested.
• flavor The Openstack flavor id. This flavor will be used for both master and worker nodes. 2 GB RAM flavors and 20 GB disk are adequate. Flavor size will vary based on application needs.
• ssh_user This blueprint uses the Fabric plugin and so requires ssh credentials.
• ssh_keyname The Openstack ssh key to attach to the compute nodes (both master and worker).
• ssh_keyfile This blueprint uses the Fabric plugin and so requires ssh credentials.

Other Configuration

The blueprint contains a dsl_definitions block to specify the Openstack credentials:

• username The Openstack user name
• password The Openstack password
• tenant_name The Openstack tenant
• auth_url The Openstack Keystone URL

swarm-openstack-blueprint.yaml

swarm-scale-blueprint.yaml

Docker Swarm Plugin

The Docker Swarm Plugin provides support for deploying services onto Docker Swarm clusters, as well as support for Docker Compose.

Types

cloudify.swarm.Manager

Overview

A type that represents a Swarm manager not managed by Cloudify. If a Cloudify managed manager is used, the Cloudify proxy plugin should be used instead.

Properties

• ip The IPV4 address of the Swarm manager
• port The port the manager REST API is listening on (default 2375)
• ssh_user An ssh user for operations that require ssh (Docker Compose)
• ssh_keyfile An ssh private key for operations that require ssh (Docker Compose)

cloudify.swarm.Microservice

Overview

The cloudify.swarm.Microservice type represents a Docker Swarm service. It can be configured to use TOSCA-style properties or point to an external Swarm yaml descriptor.

Properties

• compose_file The path to a Docker compose descriptor file. If set, all other properties are ignored.
• all other properties are translated into the Docker REST service create API call. Properties in the blueprint are encoded with underscores between words (e.g. log_driver) and converted internally to the REST API body camel case (e.g. LogDriver). See comments in the plugin.yaml for an extensive example.

Relationships

• cloudify.swarm.relationships.microservice_contained_in_manager This relationship connects a Microservice to a manager. The implementation allows the target to be either a cloudify.swarm.Manager type or a cloudify.nodes.DeploymentProxy type.

Kubernetes Blueprint

Kubernetes Plugin

The Kubernetes Plugin provides support for deploying services on Kubernetes clusters.

Kubernetes Blueprint

The Kubernetes Blueprint creates and manages a Kubernetes cluster on Openstack and Amazon EC2.

Mesos Blueprint

The Mesos creates and manages Mesos clusters on Openstack.