Startup configuration

In the Ankaios system it is mandatory to specify all the nodes and workloads that are going to be run. Currently the startup configuration is provided as a file which is in YAML file format and can be passed to the Ankaios server through a command line argument. Depending on the demands towards Ankaios, the startup configuration can later be provided in a different way.

Configuration structure

The startup configuration is composed of a list of workload specifications within the workloads object. A workload specification must contain the following information:

• workload name(via field key), specify the workload name to identify the workload in the Ankaios system.
• runtime, specify the type of the runtime. Currently supported value is podman.
• agent, specify the name of the owning agent which is going to execute the workload.
• restart, specify if the workload shall be restarted when it exits. Currently not implemented.
• updateStrategy, specify the update strategy which can be one of the following values:
  • UNSPECIFIED
  • AT_LEAST_ONCE
  • AT_MOST_ONCE
• accessRights, specify lists of access rules for allow and deny (currently not implemented and shall be set to empty list for both).
• tags, specify a list of key value pairs.
• runtimeConfig, specify as a string the configuration for the runtime whose configuration structure is specific for each runtime, e.g., for podman runtime the PodmanRuntimeConfig is used.

Example startup-config.yaml file:

workloads:
  nginx: # this is used as the workload name which is 'nginx'
    runtime: podman
    agent: agent_A
    restart: true
    updateStrategy: AT_MOST_ONCE
    accessRights:
      allow: []
      deny: []
    tags:
      - key: owner
        value: Ankaios team
    runtimeConfig: |
      image: docker.io/nginx:latest
      ports:
      - containerPort: 80
        hostPort: 8081
  api_sample: # this is used as the workload name which is 'api_sample'
    runtime: podman
    agent: agent_A
    restart: true
    updateStrategy: AT_MOST_ONCE
    accessRights:
      allow: []
      deny: []
    tags:
      - key: owner
        value: Ankaios team
    runtimeConfig: |
      image: ankaios_workload_api_example

PodmanRuntimeConfig

The runtime configuration for the podman runtime is specified as followed:

image: <string>                   # Image repository or image id
command: <vector of strings>      # Entrypoint array. Not executed in a shell. The container image's ENTRYPOINT is used if this is not provided.
args: <vector of strings>         # Arguments to the entrypoint. The container image's CMD is used if this is not provided.
env:  <vector of name/value pair>  # Key/value pairs provided as environment variables in the container
ports: <vector of port mappings>  # List of ports to be exposed
remove: <true|false>              # Specify whether the container shall be removed after exited