Built-in Trait Types

This document provides reference information for built-in trait types.

Container

Acts as the base trait for containerized workload components.

Example

apiVersion: po.rapd.app/v1beta1
kind: Application
metadata:
  name: application-local-webservice
  namespace: default-env
spec:
  version: "1.0"
  revisionHistory: 3
  components:
    - type: webservice.container
      name: first-component
      target: default
      traits:
        - type: container
          image: nginx
          ports:
            - port: 80
              name: "http"
              protocol: "TCP"
            - port: 3000
              name: "testpatch"
              protocol: "TCP"
          env:
            - name: testenv
              value: e1

Schema

Name	Type	Required	Default	Description
type	”container”	V		Type name.
image	string	V		Container image
imagePullPolicy	string			”Always”, “Never”, “IfNotPresent”
imagePullSecrets	[]string
cmd	[]string
args	[]string
ports	[]Port
env	[]Env
volumeMounts	[]VolumeMount
livenessProbe	LivenessProbe
readinessProbe	ReadinessProbe
serviceAccountName	string

Port

Name	Type	Required	Default	Description
port	int	v
name	string
protocol	string

Env

Name	Type	Required	Default	Description
name	string	v
value	string
valueFrom	ValueFrom

value or valueFrom one of these must be required

ValueFrom

Name	Type	Required	Default	Description
secretKeyRef	SecretKeyRef

SecretKeyRef

Name	Type	Required	Default	Description
name	string	v		secret name
key	string	v		secret value

VolumeMount

Name	Type	Required	Default	Description
emptyDir	EmptyDir
hostPath	HostPath
pvc	PVC
secret	Secret

EmptyDir

Name	Type	Required	Default	Description
name	string	v
mountPath	string	v
subPath	string
medium	string		""	“Memory” or “”

HostPath

Name	Type	Required	Default	Description
name	string	v
mountPath	string	v
subPath	string
path	string	v		Host filesystem path.

PVC

Name	Type	Required	Default	Description
name	string	v
mountPath	string	v
subPath	string
claimName	string	v

Secret

Name	Type	Required	Default	Description
name	string	v
subPath	string
mountPath	string	v
secretName	string	v

HttpGet

Name	Type	Required	Default	Description
path	string	v
port	int	v
host	string
scheme	string
httpHeaders	[]HttpHeader

HttpHeader

Name	Type	Required	Default	Description
name	string	v
value	string	v

TcpSocket

Name	Type	Required	Default	Description
ip	string	v
hostnames	[]string	v

LivenessProbe

Name	Type	Required	Default	Description
exec	Exec
httpGet	HttpGet
tcpSocket	TcpSocket
initialDelaySeconds	int		10
timeoutSeconds	int		1
successThreshold	int		1
failureThreshold	int		3

ReadinessProbe

Name	Type	Required	Default	Description
exec	Exec
httpGet	HttpGet
tcpSocket	TcpSocket
initialDelaySeconds	int		10
timeoutSeconds	int		1
successThreshold	int		1
failureThreshold	int		3

StartupProbe

Name	Type	Required	Default	Description
exec	Exec
httpGet	HttpGet
tcpSocket	TcpSocket
initialDelaySeconds	int		10
timeoutSeconds	int		1
successThreshold	int		1
failureThreshold	int		3

Exec

Name	Type	Required	Default	Description
command	[]string	v

Sidecars

The trait for declaring sidecars for containerized worloads.

Example

apiVersion: po.rapd.app/v1beta1
kind: Application
metadata:
  name: nginx-sidecar
spec:
  version: "1.0"
  revisionHistory: 3
  components:
    - type: webservice.container
      name: first-component
      target: default
      traits:
        - type: container
          image: nginx
          ports:
            - port: 80
              name: "http"
              protocol: "TCP"
        - type: sidecar
          sidecar:
          - image: busybox
            command: ['sh', '-c', 'sleep 3600']

Schema

Name	Type	Required	Default	Description
type	”sidecars”	V		Type name
sidecar	[]Sidecar	V		Sidecar definition.

Sidecar

Name	Type	Required	Default	Description
image	string	V		Container image name.
cmd	[]string			Entry Command.
args	[]string			Command line arguments.
env	[]Env			Environment variables.
volumes	string			Non-persistent volume shared with the main container.
livenessProbe	LivenessProbe
readlinessProbe	ReadinessProbe

Volume

Name	Type	Required	Default	Description
name	string	V		Name for the underlying emptyDir。
path	string	V		The path to mount the volume.
mainPath	string			THe mount path in the main container. Same as path is not given.

Scaler

Manually specifying relica count of workload components.

Example

apiVersion: po.rapd.app/v1beta1
kind: Application
metadata:
  name: nginx-scaler-webservice
  namespace: default-env
spec:
  version: "1.0"
  revisionHistory: 3
  components:
    - type: webservice.container
      name: mycomponent
      target: default
      traits:
        - type: container
          image: nginx
          ports:
            - port: 80
              name: "http"
              protocol: "TCP"
        - type: scaler
          replicas: 3

Schema

Name	Type	Required	Default	Description
type	”scaler”	V		Type name.
replica	int	V

Resources

For declaring resource limits of attched components.

Example

apiVersion: po.rapd.app/v1beta1
kind: Application
metadata:
  name: nginx-resource-webservice
  namespace: default-env
spec:
  version: "1.0"
  revisionHistory: 3
  components:
    - type: webservice.container
      name: mycomponent
      target: default
      traits:
        - type: container
          image: nginx
          ports:
            - port: 80
              name: "http"
              protocol: "TCP"
        - type: resources
          memory: "128Mi"
          cpu: 1.2
          limits:
            cpu: 1.4
            memory: "158Mi"

Schema

Name	Type	Required	Default	Description
type	”resources”	V		Type name.
cpu	double		1	CPU requests and limits for the component.
memory	string		2048Mi	Memory requests and limits for the component.
limits	Limits			Specify resource limits.

Limits

Name	Type	Required	Default	Description
cpu	double		same as Resources.cpu	CPU limit for the component.
memory	string		same as Resources.memory	Memory limits for the component.

Properties

Generic key-value tables which are used as the data source for application configrations. For example, for creating a ConfigMap in target K8s cluster.

Example

apiVersion: po.rapd.app/v1beta1
kind: Application
metadata:
  name: nginx-property-webservice
  namespace: default-env
spec:
  version: "1.0"
  revisionHistory: 3
  components:
    - type: webservice.container
      name: mycomponent
      target: default
      traits:
        - type: container
          image: nginx
          ports:
            - port: 80
              name: "http"
              protocol: "TCP"
          volumeMounts:
            - configMap:
                name: mmmm
                configName: myvolume
                mountPath: /config
                items:
                  - key: mykey
                    path: mykey
                  - key: docs
                    path: newdocs
        - type: properties
          entries:
            mykey: myvalue
            docs: document value
          name: myvolume

Schema

Name	Type	Required	Default	Description
type	”properties”	V		Type name.
entries	mapping[string] string			key-value map.

Ingress-Route

For declaring external HTTP endpoints.

Example

apiVersion: po.rapd.app/v1beta1
kind: Application
metadata:
  name: example
spec:
  components:
    - name: web-server
      type: webservice
      properties:
        image: nginx
        port: 8000
      traits:
        - type: ingressRoute
          paths:
            “/”: 8000

Schema

Name	Type	Required	Default	Description
type	”ingressRoute”	V		Type name.
hostname	string			Matched hostname.
paths	map[string] int	v		path to port number mappings
pathType	string		Prefix	Path matching algorithm. “Prefix”, “Exact”, “ImplementationSpecific”
ingressClassName	string			Ingress class name

Connections

Specifying the bindings from client to supplier components.

Example

apiVersion: po.rapd.app/v1
kind: Application
metadata:
  name: my-wp
spec:
  version: "1.0"
  revisionHistory: 3
  components:
    - type: webservice.container
      name: wordpress
      target: bind-gcp
      traits:
        - type: container
          image: wordpress
          ports:
            - port: 80
              name: "http"
              protocol: "TCP"
        - type: ingress-route
          paths:
            "/": 80
          pathType: Prefix
        - type: connections
          connections:
          - supplierName: my-wp-wordpress-mysql
            envRefs:
            - secretKey: username
              envName: WORDPRESS_DB_USER
            - secretKey: password
              envName: WORDPRESS_DB_PASSWORD
            - secretKey: host
              envName: WORDPRESS_DB_HOST
            - secretKey: db
              envName: WORDPRESS_DB_NAME

    - type: database.mysql
      name: wordpress-mysql
      target: bind-mysql-gcp

Schema

Name	Type	Required	Default	Description
type	”connections”	V		Type name.
connections	[]Connection	V		Connection data.

Connection

Name	Type	Required	Default	Description
supplierName	string	V		Name of the target component.
envRefs	EnvRef			Bind connection data to environment variables.
volume	Volume			Mount connection data to a filesystem path.

EnvRef

Name	Type	Required	Default	Description
secretKey	string	V		The key to the connection secret.
envName	string	V		environment variable name.

Volume

Name	Type	Required	Default	Description
mountPath	string	V		Mount location.
subPath	string	V

Rollout-Rolling

Rolling Update Deployment Strategy: This strategy allows both old and new versions to coexist during the deployment process. Different users may simultaneously access the old and new versions. The replicas of the old version gradually get removed, while an equal number of new version replicas are created until all old version replicas have been replacedㄡ

Compatible Component Types

The trait may be applied to webservice components.

Example

apiVersion: po.rapd.app/v1
kind: Application
metadata:
  name: example
spec:
  components:
    - name: web-server
      type: webservice
      properties:
        image: nginx
        port: 8000
      traits:
        - type: “rollout-rolling”
          maxSurge: 20%
          maxUnavailable: 10%

Schema

Name	Type	Required	Default	Description
type	”rollout-rolling”	V		Type name
maxSurge	string		20%	amount of pods more than the desired number of Pods.this fields can be an absolute number or the percentage ( ex: 2 or 10% )
maxUnavailable	string		20%	amount of pods that can be unavailable during the update process. In number of percentage format ( ex: 2 or 10% )

• Total deployment time： Ceil( 100/stepWeight ) * interval seconds
• Total rollout steps：Ceil( 100/stepWeight )

Rollout-Recreate

The recreate deployment strategy is the simplest approach used in cloud-native application deployment. Here’s how it works:

1. Initial Deployment:

• Version 1 of the application is deployed.
• All pods running version 1 are active.

2. Deployment Process:

• The deployment process begins.
• All pods running version 1 are deleted.
• Immediately after, version 2 of the application is deployed.

3. Drawbacks:

• The main drawback of recreate deployments is the small window of downtime during which the old version is removed and the new version is instantiated1.

In summary, recreate deployments provide a straightforward way to transition from one version to another, but they come with a brief interruption in service.

Example

apiVersion: po.rapd.app/v1
kind: Application
metadata:
  name: example
spec:
  components:
    - name: web-server
      type: webservice
      properties:
        image: nginx
        port: 8000
      traits:
        - type: “rollout-recreate”

Schema

Name	Type	Required	Default	Description
type	”rollout-recreate”	V		Type name.

Rollout-Canary

When using the K8s Gateway API to implement underlying traffic splitting services, ensure that the K8s Gateway API resources are installed. This strategy deploys both new and old versions concurrently, gradually directing user traffic toward the replicas of the new version. If everything goes smoothly, this process will continue until all traffic exclusively uses the new version. In case of any issues, it’s possible to redirect all traffic back to the original version.

Example

apiVersion: po.rapd.app/v1
kind: Application
metadata:
  name: example
spec:
  components:
    - name: web-server
      type: webservice
      properties:
        image: nginx
        port: 8000
      traits:
        - type: “rollout-canary”
          interval: 30
          stepPercentage: 50

Schema

Name	Type	Required	Default	Description
type	”rollout-canary”	V		Type name
interval	int		10	Adjust traffic every interval seconds.
stepPercentage	int		20	percentage of traffice routed to new version during the update process.

• Total time： Ceil( 100/stepPercentage ) * interval 秒
• Totsl rollout steps：Ceil( 100/stepPercentage )

Rollout-BlueGreen

Blue-green deployment strategy.

Example

apiVersion: po.rapd.app/v1
kind: Application
metadata:
  name: example
spec:
  components:
    - name: web-server
      type: webservice
      properties:
        image: nginx
        port: 8000
      traits:
        - type: “rollout-blue-green”

Name	Type	Required	Default	Description
type	”rollout-blue-green”	V		Name of the trait type