This project contains a plugin that enables Cloudify to install, configure, and run services on a Kubernetes cluster. Note: currently installs Kubernetes version 1.2.4.
Limitations (as of 5/2/2016):
- Only tested on Ubuntu 14
- Tested on Openstack Helion and Kilo
- Tested on Cloudify 3.2.1 and 3.3.1
Represents a Kuberenets master node. This is the only essential node in the plugin. All other node types and workflows require a master node to be defined. By default, it will install Kubernetes to the identified host, but it can be configured to merely connect to an existing master. If desired, the blueprint will also install docker if the install_docker property is true.
Interesting properties
- install_agent boolean (default=false) that determines whether to install a Cloudify agent on the target host.
- install_docker boolean (default=false) that determines whether the plugin will install docker before attempting to install Kuberenets
- install boolean (default=true) that determines whether the plugin will install Kubernetes itself. If
false, it will simply connect - master_port int (default 8080) that indicates where Kubernetes will listen for requests
Represents a Kubernetes "node" or "minion". Unused if simply connecting to an existing cluster. Extracts connection information to the master via the cloudify.kubernetes.relationships.connected_to_master relationship.
Represents a "microservice" in a Kubernetes cluster. Requires the cloudify.kubernetes.relationships.connected_to_master relationship to get connection information. Can define a service by plugin properties, by embedded Kubernetes native YAML, and by referring to a standard Kubernetes YAML deployment manifest while permitting overrides. When using either form of native YAML, the actual Kubernetes action performed is determined by the configuration, which means that in reality it may or may not actually create a Kubernetes service, replication control, or other artifact. Actual command execution on Kubernetes is performed by the fabric plugin by remotely executing the Kubernetes kubectl executable on the master node.
Interesting properties
| Property | Description |
|---|---|
| name | service name |
| image | image name |
| port | service listening port |
| target_port | container port (default:port) |
| protocol | TCP/UDP (default TCP) |
| replicas | number of replicas (default 1) |
| run_overrides | json overrides for kubectl "run" |
| expose_overrides | json overrides for kubectl "expose" |
| Property | Description |
|---|---|
| config | indented children are native Kubernetes YAML |
| Property | Description |
|---|---|
| config_path | path to Kubernetes manifest |
| config_overrides | replacement values for external manifest |
Just retrieves the master ip and port for use by the dependent node.
With the exception of the kube_scale workflow (covered below), these workflows just delegate to kubectl on the master. They all share a parameter called master. The master parameter is set to the node name of the Kubernetes master that the workflow is to be run against. Another pattern is to provide many (but not all) of the parameters that kubectl accepts, but using the overrides property as a catch all.
These workflows are provided as samples. It should be understood that any actual producion blueprint would only implement workflows relevant to the blueprint purpose, which may or may not include the following, and probably contain others.
| Workflow name | Description |
|---|---|
| kube_run | kubectl run equivalent |
| kube_expose | kubectl run equivalent |
| kube_stop | kubectl stop equivalent |
| kube_delete | kubectl delete equivalent |
The function of kube_scale is not to scale Kubernetes minion/node servers. Scaling Kubernetes is handled by the standard scale workflow in Cloudify. kube_scale scales deployed Microservices. The amount of scale can be supplied as either an fixed number (e.g. 5) or an increment (e.g. +2 or -1). The parameters are as follows:
| Parameter | Description |
|---|---|
| master | the master node in the blueprint. Can be a standard node or a deployment proxy. |
| ssh_user | the user that Kubernetes was installed as |
| ssh_keyfilename | the key file name for the ssh_user |
| name | the name of the Microservice node |
| amount | the scale value (e.g. 2), or the scale increment (e.g. "+1). |