server.md

Server

A Server is a OAM core workload type to define long-running, scalable workloads that have a network endpoint with a stable name to receive network traffic for the component as a whole. Common use cases include web applications and services that expose APIs. The Server workload type has the following characteristics:

• Defines a container runtime where zero or more replicas of the same container may be run simultaneously.
• An application operator can increase or decrease the number of component replicas by applying and configuring traits when available.
• A Server is daemonized. A runtime MUST attempt to restart replicas that exit regardless of error code.
• A Server has a network endpoint with an automatically assigned virtual IP address (VIP) and DNS name addressable within the network scope to which the component belongs.

If a Server does not provide at least one port on at least one container, implementations SHOULD emit an error.

How to use?

1. Install below workload definition in your OAM based platform:

   apiVersion: core.oam.dev/v1beta1
   kind: WorkloadDefinition
   metadata:
     name: Server
   spec:
     definitionRef:
       name: containerizedworkloads.core.oam.dev # the reference of schema for this workload type. In Kubernetes it should be a full name of API resource

   Note: this workload references ContainerizedWorkload as schema.

2. Define a component references Server as workloads:

   apiVersion: core.oam.dev/v1beta1
   kind: ComponentDefinition
   metadata:
     name: webserver
     annotations:
       definition.oam.dev/description: "webserver is a combo of Deployment + Service"
   spec:
     workload:
       type: Server # reference above workload definition by name.
     schematic:
       ... # CUE code to define user schematic.