Functions Definition Language (FDL)

OSCAR services are typically defined via the Functions Definition Language (FDL) to be deployed via the OSCAR CLI. Alternative approaches are using the web-based wizard in the OSCAR UI or, for a programmatic integration, via the OSCAR API.

ℹ️

It is called Functions Definition Language instead of Services Definition Language, because the definition was initially designed for SCAR, which supports Lambda functions.

Example:

functions:
  oscar:
  - oscar-test:
      name: plants
      memory: 2Gi
      cpu: '1.0'
      image: grycap/oscar-theano-plants
      script: plants.sh
      input:
      - storage_provider: minio.default
        path: example-workflow/in
      output:
      - storage_provider: minio.default
        path: example-workflow/med
  - oscar-test:
      name: grayify
      memory: 1Gi
      cpu: '1.0'
      image: grycap/imagemagick
      script: grayify.sh
      interlink_node_name: vega-new-vk
      expose:
        min_scale: 3 
        max_scale: 7 
        port: 5000  
        cpu_threshold: 70 
        nodePort: 30500
        set_auth: true
        rewrite_target: true
        default_command: true
      input:
      - storage_provider: minio.default
        path: example-workflow/med
      output:
      - storage_provider: minio.default
        path: example-workflow/res
      - storage_provider: onedata.my_onedata
        path: result-example-workflow
      - storage_provider: webdav.dcache
        path: example-workflow/res

storage_providers:
  onedata:
    my_onedata:
      oneprovider_host: my_provider.com
      token: my_very_secret_token
      space: my_onedata_space
  webdav:
    dcache:
      hostname: my_dcache.com
      login: my_username
      password: my_password

Top level parameters

Field	Description
functions Functions	Mandatory parameter to define a Functions Definition Language file. Note that "functions" instead of "services" has been used in order to keep compatibility with SCAR
storage_providers StorageProviders	Parameter to define the credentials for the storage providers to be used in the services
clusters map[string]Cluster	Configuration for the OSCAR clusters that can be used as service's replicas, being the key the user-defined identifier for the cluster. Optional

Functions

Field	Description
oscar map[string]Service array	Main object with the definition of the OSCAR services to be deployed. The components of the array are Service maps, where the key of every service is the identifier of the cluster where the service (defined as the value of the entry on the map) will be deployed.

Service

Field	Description
name string	The name of the service
cluster_id string	Identifier for the current cluster, used to specify the cluster's StorageProvider in job delegations. OSCAR-CLI sets it using the cluster_id from the FDL. Optional. (default: "")
image string	Docker image for the service
vo string	Virtual Organization (VO) in which the user creating the service is enrolled. Optional (default: "")
allowed_users string array	Array of EGI UIDs to grant specific user permissions on the service. If empty, the service is considered as accesible to all the users with access to the OSCAR cluster. (Enabled since OSCAR version v3.0.0).
alpine boolean	Set if the Docker image is based on Alpine. If true, a custom release of the faas-supervisor will be used. Optional (default: false)
script string	Local path to the user script to be executed inside the container created out of the service invocation
file_stage_in bool	Skip the download of the input files by the faas-supervisor (default: false)
image_pull_secrets string array	Array of Kubernetes secrets. Only needed to use private images located on private registries.
memory string	Memory limit for the service following the kubernetes format. Optional (default: 256Mi)
cpu string	CPU limit for the service following the kubernetes format. Optional (default: 0.2)
enable_gpu bool	Enable the use of GPU. Requires a device plugin deployed on the cluster (More info: Kubernetes device plugins). Optional (default: false)
enable_sgx bool	Enable the use of SGX plugin on the cluster containers. (More info: SGX plugin documentation). Optional (default: false)
image_prefetch bool	Enable the use of image prefetching (retrieve the container image in the nodes when creating the service). Optional (default: false)
total_memory string	Limit for the memory used by all the service's jobs running simultaneously. Apache YuniKorn's' scheduler is required to work. Same format as Memory, but internally translated to MB (integer). Optional (default: "")
total_cpu string	Limit for the virtual CPUs used by all the service's jobs running simultaneously. Apache YuniKorn's' scheduler is required to work. Same format as CPU, but internally translated to millicores (integer). Optional (default: "")
synchronous SynchronousSettings	Struct to configure specific sync parameters. This settings are only applied on Knative ServerlessBackend. Optional.
expose ExposeSettings	Allows to expose the API or UI of the application run in the OSCAR service outside of the Kubernetes cluster. Optional.
replicas Replica array	List of replicas to delegate jobs. Optional.
rescheduler_threshold string	Time (in seconds) that a job (with replicas) can be queued before delegating it. Optional.
log_level string	Log level for the faas-supervisor. Available levels: NOTSET, DEBUG, INFO, WARNING, ERROR and CRITICAL. Optional (default: INFO)
input StorageIOConfig array	Array with the input configuration for the service. Optional
output StorageIOConfig array	Array with the output configuration for the service. Optional
environment EnvVarsMap	The user-defined environment variables assigned to the service. Optional
annotations map[string]string	User-defined Kubernetes annotations to be set in job's definition. Optional
labels map[string]string	User-defined Kubernetes labels to be set in job's definition. Optional
interlink_node_name string	Name of the virtual kubelet node (if you are using InterLink nodes) Optional

SynchronousSettings

Field	Description
min_scale integer	Minimum number of active replicas (pods) for the service. Optional. (default: 0)
max_scale integer	Maximum number of active replicas (pods) for the service. Optional. (default: 0 (Unlimited))

ExposeSettings

Field	Description
min_scale integer	Minimum number of active replicas (pods) for the service. Optional. (default: 1)
max_scale integer	Maximum number of active replicas (pods) for the service. Optional. (default: 10 (Unlimited))
port integer	Port inside the container where the API is exposed. (value: 0 , the service wont be exposed.)
cpu_threshold integer	Percent of use of CPU before creating other pod (default: 80 max:100). Optional.
nodePort integer	Change the access method from the domain name to the public ip. Optional.
set_auth bool	Create credentials for the service, composed of the service name as the user and the service token as the password. (default: false). Optional.
rewrite_target bool	Target the URI where the traffic is redirected. (default: false). Optional.
default_command bool	Select between executing the container's default command and executing the script inside the container. (default: false). Optional.

Replica

Field	Description
type string	Type of the replica to re-send events (can be oscar or endpoint)
cluster_id string	Identifier of the cluster as defined in the "clusters" FDL field. Only used if Type is oscar
service_name string	Name of the service in the replica cluster. Only used if Type is oscar
url string	URL of the endpoint to re-send events (HTTP POST). Only used if Type is endpoint
ssl_verify boolean	Parameter to enable or disable the verification of SSL certificates. Only used if Type is endpoint. Optional. (default: true)
priority integer	Priority value to define delegation priority. Highest priority is defined as 0. If a delegation fails, OSCAR will try to delegate to another replica with lower priority. Optional. (default: 0)
headers map[string]string	Headers to send in delegation requests. Optional

StorageIOConfig

Field	Description
storage_provider string	Reference to the storage provider defined in storage_providers. This string is composed by the provider's name (minio, s3, onedata) and the identifier (defined by the user), separated by a point (e.g. "minio.myidentifier")
path string	Path in the storage provider. In MinIO and S3 the first directory of the specified path is translated into the bucket's name (e.g. "bucket/folder/subfolder")
suffix string array	Array of suffixes for filtering the files to be uploaded. Only used in the output field. Optional
prefix string array	Array of prefixes for filtering the files to be uploaded. Only used in the output field. Optional

EnvVarsMap

Field	Description
Variables map[string]string	Map to define the environment variables that will be available in the service container

StorageProviders

Field	Description
minio map[string]MinIOProvider	Map to define the credentials for a MinIO storage provider, being the key the user-defined identifier for the provider
s3 map[string]S3Provider	Map to define the credentials for an Amazon S3 storage provider, being the key the user-defined identifier for the provider
onedata map[string]OnedataProvider	Map to define the credentials for a Onedata storage provider, being the key the user-defined identifier for the provider
webdav map[string]WebDavProvider	Map to define the credentials for a storage provider accesible via WebDAV protocol, being the key the user-defined identifier for the provider

Cluster

Field	Description
endpoint string	Endpoint of the OSCAR cluster API
auth_user string	Username to connect to the cluster (basic auth)
auth_password string	Password to connect to the cluster (basic auth)
ssl_verify boolean	Parameter to enable or disable the verification of SSL certificates

MinIOProvider

Field	Description
endpoint string	MinIO endpoint
verify bool	Verify MinIO's TLS certificates for HTTPS connections
access_key string	Access key of the MinIO server
secret_key string	Secret key of the MinIO server
region string	Region of the MinIO server

S3Provider

Field	Description
access_key string	Access key of the AWS S3 service
secret_key string	Secret key of the AWS S3 service
region string	Region of the AWS S3 service

OnedataProvider

Field	Description
oneprovider_host string	Endpoint of the Oneprovider
token string	Onedata access token
space string	Name of the Onedata space

WebDAVProvider

Field	Description
hostname string	Provider hostname
login string	Provider account username
password string	Provider account password