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Web Service

Service-oriented components are components that support external access to services with the container as the core, and their functions cover the needs of most of he microservice scenarios.

Please copy shell below and apply to the cluster:

cat <<EOF | kubectl apply -f -
# YAML begins
apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
name: website
spec:
components:
- name: frontend
type: webservice
properties:
image: oamdev/testapp:v1
cmd: ["node", "server.js"]
port: 8080
cpu: "0.1"
env:
- name: FOO
value: bar
# YAML ends
EOF

You can also save the YAML file as website.yaml and use the kubectl apply -f website.yaml command to deploy.

Next, check the deployment status of the application through kubectl get application <application name> -o yaml:

$ kubectl get application website -o yaml
apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
name: website
... # Omit non-critical information
spec:
components:
- name: frontend
properties:
... # Omit non-critical information
type: webservice
status:
conditions:
- lastTransitionTime: "2021-08-28T10:26:47Z"
reason: Available
status: "True"
... # Omit non-critical information
type: HealthCheck
observedGeneration: 1
... # Omit non-critical information
services:
- healthy: true
name: frontend
workloadDefinition:
apiVersion: apps/v1
kind: Deployment
status: running

When we see that the status.services.healthy field is true and the status is running, it means that the entire application is delivered successfully.

If status shows as rendering or healthy as false, it means that the application has either failed to deploy or is still being deployed. Please proceed according to the information returned in kubectl get application <application name> -o yaml.

You can also view through the CLI of vela, using the following command:

$ vela ls
APP COMPONENT TYPE TRAITS PHASE HEALTHY STATUS CREATED-TIME
website frontend webservice running healthy 2021-08-28 18:26:47 +0800 CST

We also see that the PHASE of the app is running and the STATUS is healthy.

Attributes#

NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
cmdCommands to run in the container[]stringfalse
envDefine arguments by using environment variables[]envfalse
imageWhich image would you like to use for your servicestringtrue
portWhich port do you want customer traffic sent tointtrue80
imagePullPolicySpecify image pull policy for your servicestringfalse
cpuNumber of CPU units for the service, like 0.5 (0.5 CPU core), 1 (1 CPU core)stringfalse
memorySpecifies the attributes of the memory resource required for the container.stringfalse
volumesDeclare volumes and volumeMounts[]volumesfalse
livenessProbeInstructions for assessing whether the container is alive.livenessProbefalse
readinessProbeInstructions for assessing whether the container is in a suitable state to serve traffic.readinessProbefalse
imagePullSecretsSpecify image pull secrets for your service[]stringfalse

readinessProbe#

NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
execInstructions for assessing container health by executing a command. Either this attribute or theexecfalse
httpGet attribute or the tcpSocket attribute MUST be specified. This attribute is mutually exclusive
with both the httpGet attribute and the tcpSocket attribute.
httpGetInstructions for assessing container health by executing an HTTP GET request. Either this attributehttpGetfalse
or the exec attribute or the tcpSocket attribute MUST be specified. This attribute is mutually
exclusive with both the exec attribute and the tcpSocket attribute.
tcpSocketInstructions for assessing container health by probing a TCP socket. Either this attribute or thetcpSocketfalse
exec attribute or the httpGet attribute MUST be specified. This attribute is mutually exclusive with
both the exec attribute and the httpGet attribute.
initialDelaySecondsNumber of seconds after the container is started before the first probe is initiated.inttrue0
periodSecondsHow often, in seconds, to execute the probe.inttrue10
timeoutSecondsNumber of seconds after which the probe times out.inttrue1
successThresholdMinimum consecutive successes for the probe to be considered successful after having failed.inttrue1
failureThresholdNumber of consecutive failures required to determine the container is not alive (liveness probe) orinttrue3
not ready (readiness probe).

tcpSocket#

NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
portThe TCP socket within the container that should be probed to assess container health.inttrue

httpGet#

NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
pathThe endpoint, relative to the port, to which the HTTP GET request should be directed.stringtrue
portThe TCP socket within the container to which the HTTP GET request should be directed.inttrue
httpHeaders[]httpHeadersfalse
httpHeaders#
NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
namestringtrue
valuestringtrue
exec#
NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
commandA command to be executed inside the container to assess its health. Each space delimited token of[]stringtrue
the command is a separate array element. Commands exiting 0 are considered to be successful probes,
whilst all other exit codes are considered failures.

livenessProbe#

NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
execInstructions for assessing container health by executing a command. Either this attribute or theexecfalse
httpGet attribute or the tcpSocket attribute MUST be specified. This attribute is mutually exclusive
with both the httpGet attribute and the tcpSocket attribute.
httpGetInstructions for assessing container health by executing an HTTP GET request. Either this attributehttpGetfalse
or the exec attribute or the tcpSocket attribute MUST be specified. This attribute is mutually
exclusive with both the exec attribute and the tcpSocket attribute.
tcpSocketInstructions for assessing container health by probing a TCP socket. Either this attribute or thetcpSocketfalse
exec attribute or the httpGet attribute MUST be specified. This attribute is mutually exclusive with
both the exec attribute and the httpGet attribute.
initialDelaySecondsNumber of seconds after the container is started before the first probe is initiated.inttrue0
periodSecondsHow often, in seconds, to execute the probe.inttrue10
timeoutSecondsNumber of seconds after which the probe times out.inttrue1
successThresholdMinimum consecutive successes for the probe to be considered successful after having failed.inttrue1
failureThresholdNumber of consecutive failures required to determine the container is not alive (liveness probe) orinttrue3
not ready (readiness probe).
tcpSocket#
NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
portThe TCP socket within the container that should be probed to assess container health.inttrue
httpGet#
NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
pathThe endpoint, relative to the port, to which the HTTP GET request should be directed.stringtrue
portThe TCP socket within the container to which the HTTP GET request should be directed.inttrue
httpHeaders[]httpHeadersfalse
httpHeaders#
NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
namestringtrue
valuestringtrue
exec#
NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
commandA command to be executed inside the container to assess its health. Each space delimited token of[]stringtrue
the command is a separate array element. Commands exiting 0 are considered to be successful probes,
whilst all other exit codes are considered failures.

volumes#

NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
namestringtrue
mountPathstringtrue
typeSpecify volume type, options: "pvc","configMap","secret","emptyDir"stringtrue

env#

NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
nameEnvironment variable namestringtrue
valueThe value of the environment variablestringfalse
valueFromSpecifies a source the value of this var should come fromvalueFromfalse

valueFrom#

NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
secretKeyRefSelects a key of a secret in the pod's namespacesecretKeyReftrue

secretKeyRef#

NAMEDESCRIPTIONTYPEREQUIREDDEFAULT
nameThe name of the secret in the pod's namespace to select fromstringtrue
keyThe key of the secret to select from. Must be a valid secret keystringtrue
Last updated on by Jianbo Sun