7.3 KiB
| title |
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| Deploy First Application |
Welcome to KubeVela! In this guide, we'll walk you through how to install KubeVela, and deploy your first simple application.
Installation
Make sure you have finished and verified KubeVela installation following this guide.
A Simple Application
A simple deployment definition in KubeVela looks as below:
apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
name: first-vela-app
spec:
components:
- name: express-server
type: webservice
properties:
image: crccheck/hello-world
port: 8000
traits:
- type: ingress-1-20
properties:
domain: testsvc.example.com
http:
"/": 8000
Now deploy it to KubeVela:
kubectl apply -f https://raw.githubusercontent.com/oam-dev/kubevela/master/docs/examples/vela-app.yaml
This command will deploy a web service component to target environment, which in our case is the Kubernetes cluster that KubeVela itself is installed.
After deployed, you can now directly visit this application as it already attached with a ingress trait (assume your cluster has Ingress enabled).
$ curl -H "Host:testsvc.example.com" http://<some ip address>/
<xmp>
Hello World
## .
## ## ## ==
## ## ## ## ## ===
/""""""""""""""""\___/ ===
~~~ {~~ ~~~~ ~~~ ~~~~ ~~ ~ / ===- ~~~
\______ o _,/
\ \ _,'
`'--.._\..--''
</xmp>
Deploy More Components
KubeVela allows you to deploy diverse components types. In above example, the Web Service component is actually a predefined CUE module.
You can also try:
Helm components
apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
name: app-delivering-chart
spec:
components:
- name: redis-comp
type: helm
properties:
chart: redis-cluster
version: 6.2.7
url: https://charts.bitnami.com/bitnami
repoType: helm
Terraform components
apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
name: rds-cloud-source
spec:
components:
- name: sample-db
type: alibaba-rds
properties:
instance_name: sample-db
account_name: oamtest
password: U34rfwefwefffaked
writeConnectionSecretToRef:
name: db-conn
Components from Git repository
apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
name: git-app
spec:
components:
- name: git-comp
type: kustomize
properties:
repoType: git
url: https://github.com/<path>/<to>/<repo>
git:
branch: master
path: ./app/dev/
... and many many more. Please check the Deploying Components section under User Manuals for all supported types, and even go ahead to add your own.
Attach Operational Behaviors
KubeVela is not just about deploy. It allows you to attach predefined operational behaviors (named Traits) to your components in-place. For example, let's assign a batch rollout strategy to our web service:
apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
name: rollout-trait-test
spec:
components:
- name: express-server
type: webservice
externalRevision: express-server-v1
properties:
image: stefanprodan/podinfo:4.0.3
traits:
- type: rollout
properties:
targetSize: 5
rolloutBatches:
- replicas: 2
- replicas: 3
Now whenever the image version is updated in above YAML file, the express-server component will rollout following strategy defined in rolloutBatches.
For all supported traits in KubeVela, please check Attaching Traits section under User Manuals. Not surprisingly, you can also add your own traits to KubeVela with just minimal effort.
Define Policies and Workflow
Components and traits are just the beginning of your vela sail. KubeVela is by design a full functional Continuous Delivery (CD) platform with fine grained support for hybrid/multi-cloud/multi-cluster deployment.
Let's say:
I want to deploy an micro-services application with two components, firstly to staging cluster with only 1 instance, then pause and wait for manual approval. If approved, then deploy it to production cluster but with instances scaled to 3.
Oops, imagine how many add-hoc scripts and glue code are needed in your CI/CD pipeline to achieve automation and deployment success rate in above process.
While with KubeVela, above process can be easily modeled as a declarative deployment plan as below:
apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
name: example-app
namespace: default
spec:
components:
- name: hello-world-server
type: webservice
properties:
image: crccheck/hello-world
port: 8000
traits:
- type: scaler
properties:
replicas: 1
- name: data-worker
type: worker
properties:
image: busybox
cmd:
- sleep
- '1000000'
policies:
- name: example-multi-env-policy
type: env-binding
properties:
envs:
- name: staging
placement: # selecting the cluster to deploy to
clusterSelector:
name: cluster-staging
selector: # selecting which component to use
components:
- hello-world-server
- name: prod
placement:
clusterSelector:
name: cluster-prod
patch: # overlay patch on above components
components:
- name: hello-world-server
type: webservice
traits:
- type: scaler
properties:
replicas: 3
- name: health-policy-demo
type: health
properties:
probeInterval: 5
probeTimeout: 10
workflow:
steps:
# deploy to staging env
- name: deploy-staging
type: deploy2env
properties:
policy: example-multi-env-policy
env: staging
# manual check
- name: manual-approval
type: suspend
# deploy to prod env
- name: deploy-prod
type: deploy2env
properties:
policy: example-multi-env-policy
env: prod
No more add-hoc scripts or glue code, KubeVela will get the application delivery workflow done with full automation and determinism. Most importantly, KubeVela expects you keep using the CI solutions you are already familiar with and KubeVela is fully complementary to them as the CD control plane.
For using KubeVela with your own CI pipelines and other tools, please check Best Practices section in the sidebar for more real world examples.
What's Next
All above features are just the first glance of KubeVela. For next steps, we recommend:
- Learn KubeVela's application model.
- Interested in KubeVela itself? Learn its design and architecture.