Updating Kubernetes YAML for Development

Decrease Scale

Most of the Kelda features only work when there is exactly one container per service. To meet this requirement, you must:

  • Decrease the number of replicas in your Deployments, StatefulSets, etc.
  • Disable autoscaling.

Remove Unnecessary Services

Remove services that do not make sense to run in the development environment such as scheduled tasks.

Remove Publicly Exposed Services

If you have services that are publicly exposed in production (e.g. via a LoadBalancer Service), you probably want to use Kelda tunnels to expose them during development.

Remove Node Ports

Using Kubernetes services with static NodePorts is not recommended because the number of concurrent development sessions will be limited by the number of nodes in the cluster. Each development session will bind to the port on a node, and the cluster will eventually run out of nodes with an unused instance of the port.

You have this problem if you get the following error:

Service "gateway" is invalid: spec.ports[0].nodePort: Invalid value: 30000: provided port is already allocated

Cloud Services

If you depend on cloud services in production, such as Amazon RDS, we suggest using a containerized version in your development environment. Although it’s possible to connect directly to the cloud service, using a containerized version makes it easy to enforce isolation between developers.

Data Volumes

A common pattern is to run mock copies of databases in the development environment. We suggest building a container with mocked data and deploying it to the development cluster. A sample Kube YAML file that follows this pattern for elasticsearch is shown below:

- image: elasticsearch:1
name: elasticsearch
- mountPath: /usr/share/elasticsearch/data
  name: data
- image: data-es-geoservice:latest
name: elasticsearch-data
command: [ "sh", "-c", "cp -r /usr/share/elasticsearch/data/* /usr/share/elasticsearch/data_dst" ]
- mountPath: /usr/share/elasticsearch/data_dst
  name: data
- name: data
  emptyDir: {}