rollout docs (#24)

Signed-off-by: liheng.zms <liheng.zms@alibaba-inc.com>

README.md

@@ -2,9 +2,7 @@
 [![License](https://img.shields.io/badge/license-Apache%202-4EB1BA.svg)](https://www.apache.org/licenses/LICENSE-2.0.html)
 
 ## Introduction
-Kruise Rollouts is a **Bypass** component which provides advanced deployment capabilities such as canary, traffic routing, and progressive delivery features, for a series of Kubernetes workloads, such as Deployment and CloneSet.
-
-![arch](docs/images/rollout-arch.jpg)
+Kruise Rollouts is **a Bypass component which provides advanced deployment capabilities such as canary, traffic routing, and progressive delivery features, for a series of Kubernetes workloads, such as Deployment and CloneSet.**
 
 ## Why Kruise Rollouts?
 - **Functionality**：
@@ -27,8 +25,8 @@ Kruise Rollouts is a **Bypass** component which provides advanced deployment cap
 - **Easy-integration**:
     - Easily integrate with classic or GitOps-style Kubernetes-based PaaS.
 
-## Documents
-Coming soon ...
+## Quick Start
+- [Getting Started](docs/getting_started/introduction.md)
 
 ## Community
 Active communication channels:
@@ -43,9 +41,9 @@ Active communication channels:
 - Bi-weekly Community Meeting (*English*): TODO
 
 ## Acknowledge
-- Part of the codes of this project is powered by [KubeVela Community](https://kubevela.io).
-- This project will be maintained and improved by both the communities of OpenKruise and KubeVela.
+- The global idea is from both OpenKruise and KubeVela communities, and the basic code of rollout is inherited from the KubeVela Rollout.
+- This project is maintained by both contributors from [OpenKruise](https://openkruise.io/) and [KubeVela](https://kubevela.io).
 
 ## License
-Kruise rollouts is licensed under the Apache License, Version 2.0. See [LICENSE](./LICENSE.md) for the full license text. 
+Kruise Rollout is licensed under the Apache License, Version 2.0. See [LICENSE](./LICENSE.md) for the full license text.
 

docs/getting_started/installation.md

@@ -0,0 +1,37 @@
+# Installation
+
+## Requirements
+- Install Kubernetes Cluster, requires **Kubernetes version >= 1.16**.
+- (Optional, If Use CloneSet) Helm installation of OpenKruise, **Since v1.1.0**, Reference [Install OpenKruise](https://openkruise.io/docs/installation).
+
+## Install with helm
+
+Kruise Rollout can be simply installed by helm v3.1+, which is a simple command-line tool and you can get it from [here](https://github.com/helm/helm/releases).
+
+```bash
+# Firstly add openkruise charts repository if you haven't do this.
+$ helm repo add openkruise https://openkruise.github.io/charts/
+
+# [Optional]
+$ helm repo update
+
+# Install the latest version.
+$ helm install kruise-rollout openkruise/kruise-rollout --version 0.1.0
+```
+
+## Uninstall
+
+Note that this will lead to all resources created by Kruise Rollout, including webhook configurations, services, namespace, CRDs and CR instances Kruise Rollout controller, to be deleted!
+
+Please do this ONLY when you fully understand the consequence.
+
+To uninstall kruise rollout if it is installed with helm charts:
+
+```bash
+$ helm uninstall kruise-rollout
+release "kruise-rollout" uninstalled
+```
+
+## What's Next
+Here are some recommended next steps:
+- Learn Kruise Rollout's [Basic Usage](../tutorials/basic_usage.md).

docs/getting_started/introduction.md

@@ -0,0 +1,40 @@
+# Introduction
+## What is Kruise Rollout?
+Kruise Rollouts is **a Bypass component which provides advanced deployment capabilities such as canary, traffic routing, and progressive delivery features, for a series of Kubernetes workloads, such as Deployment and CloneSet**.
+
+Kruise Rollout integrates with ingress controllers and service meshes, leveraging their traffic shaping abilities to gradually shift traffic to the new version during an update.
+In addition, the business Pods metrics analysis can be used during rollout to determine whether the release will continue or be suspended.
+
+![arch](../images/rollout-arch.jpg)
+
+## Why is Kruise Rollout?
+The native Kubernetes Deployment Object supports the **RollingUpdate** strategy which provides a basic set of safety guarantees(maxUnavailable, maxSurge) during an update. However the rolling update strategy faces many limitations:
+- **The process of batch release cannot be strictly controlled**, e.g. 20%, 40% etc. Although maxUnavailable, maxSurge can control the release rate, it will release the next batch as soon as the previous batch has been released.
+- **Can't precisely control traffic flow during the release**, e.g. 20% traffic flow rate to the new version of Pods.
+- **No ability to query external metrics to verify whether the business indicators during the upgrade process are normal**.
+
+## Features
+- **Functionality**：
+  - Support multi-batch delivery for Deployment/CloneSet.
+  - Support Nginx/ALB/Istio traffic routing control during rollout.
+
+- **Flexibility**:
+  - Support scaling up/down to workloads during rollout.
+  - Can be applied to newly-created or existing workload objects directly;
+  - Can be ridden out of at any time when you needn't it without consideration of unavailable workloads and traffic problems.
+  - Can cooperate with other native/third-part Kubernetes controllers/operators, such as HPA and WorkloadSpread.
+
+- **Non-Invasion**:
+  - Does not invade native workload controllers.
+  - Does not replace user-defined workload and traffic configurations.
+
+- **Extensibility**:
+  - Easily extend to other traffic routing types, or workload types via plugin codes.
+
+- **Easy-integration**:
+  - Easily integrate with classic or GitOps-style Kubernetes-based PaaS.
+
+## What's Next
+Here are some recommended next steps:
+- Start to [Install Kruise Rollout](./installation.md).
+- Learn Kruise Rollout's [Basic Usage](../tutorials/basic_usage.md).

docs/tutorials/basic_usage.md

@@ -0,0 +1,208 @@
+# Basic Usage
+
+This guide will demonstrate various concepts and features of Kruise Rollout by going through **Canary Release, Deployment, Nginx Ingress**.
+
+![rollout_canary](../images/rollout_canary.png)
+
+## Requirements
+- Helm installation of Kruise Rollout, Reference [Install Kruise Rollout](../getting_started/installation.md).
+- Helm installation of Nginx Ingress Controller, (e.g. **helm upgrade --install ingress-nginx ingress-nginx --repo https://kubernetes.github.io/ingress-nginx --namespace ingress-nginx**)
+
+## 1. Deploy Business Application (Contains Deployment, Service and Ingress)
+This is an example of **echoserver application, which contains ingress, service, and deployment crd resources**, as follows:
+
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: echoserver
+  labels:
+    app: echoserver
+spec:
+  replicas: 5
+  selector:
+    matchLabels:
+      app: echoserver
+  template:
+    metadata:
+      labels:
+        app: echoserver
+    spec:
+      containers:
+      - name: echoserver
+        image: cilium/echoserver:1.10.2
+        imagePullPolicy: IfNotPresent
+        ports:
+        - containerPort: 8080
+        env:
+        - name: PORT
+          value: '8080'
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: echoserver
+  labels:
+    app: echoserver
+spec:
+  ports:
+  - port: 80
+    targetPort: 8080
+    protocol: TCP
+    name: http
+  selector:
+    app: echoserver
+---
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: echoserver
+  annotations:
+    kubernetes.io/ingress.class: nginx
+spec:
+  rules:
+  - host: echoserver.example.com
+    http:
+      paths:
+      - backend:
+          service:
+            name: echoserver
+            port:
+              number: 80
+        path: /apis/echo
+        pathType: Exact
+```
+After deployed in k8s cluster, it can be accessed via nginx ingress, as follows:
+
+![echoserver](../images/echoserver_application.png)
+
+## 2. Deploy Kruise Rollout CRD
+**Kruise Rollout CRD defines the deployment rollout release process, as follows is an example of canary release,
+the first step is 20% pods, as well as routing 5% traffics to the new version.**
+```yaml
+apiVersion: rollouts.kruise.io/v1alpha1
+kind: Rollout
+metadata:
+  name: rollouts-demo
+  # The rollout resource needs to be in the same namespace as the corresponding workload(deployment, cloneSet)
+  # namespace: xxxx
+spec:
+  objectRef:
+    type: workloadRef
+    # rollout of published workloads, currently only supports Deployment, CloneSet
+    workloadRef:
+      apiVersion: apps/v1
+      kind: Deployment
+      name: echoserver
+  strategy:
+    type: canary
+    canary:
+      # canary published, e.g. 20%, 40%, 60% ...
+      steps:
+      # routing 5% traffics to the new version
+      - weight: 5
+      # Manual confirmation of the release of the remaining pods
+        pause: {}
+      # optional, The first step of released replicas. If not set, the default is to use 'weight', as shown above is 5%.
+        replicas: 20%
+      trafficRouting:
+        # echoserver service name
+      - service: echoserver
+        # nginx ingress
+        type: nginx
+        # echoserver ingress name
+        ingress:
+          name: echoserver
+```
+
+![deploy rollout](../images/deploy_rollout.png)
+
+## 3. Upgrade echoserver (Version 1.10.2 -> 1.10.3)
+Change the image version in deployment from 1.10.2 to 1.10.3, then **kubectl apply -f deployment.yaml** to the k8s cluster, as follows:
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: echoserver
+...
+spec:
+  ...
+  containers:
+  - name: echoserver
+    image: cilium/echoserver:1.10.3
+    imagePullPolicy: IfNotPresent
+```
+**The Kruise Rollout Controller listens to the above behavior and sets deployment paused=true in the webhook, then generates the corresponding canary resources based on the user-defined deployment, service, and ingress configuration.**
+
+As shown in the figure below, replicas(5)*replicas(20%)=1 new versions of Pods are published and 5% of the traffic is routed to the new version.
+
+![upgrade](../images/upgrade_echoserver.png)
+
+## 4. Approve Rollout (Release Success)
+**The Rollout status shows that the current rollout status is *StepPaused*, which means that the first 20% of Pods are released success and 5% of traffic is routed to the new version.**
+
+After that, developers can use some other methods, such as prometheus metrics business metrics,
+to determine that the release meets expectations and then continue the subsequent releases via **kubectl-kruise rollout approve rollout/rollouts-demo -n default** and wait deployment release is complete, as follows:
+
+![approve](../images/approve_rollout.png)
+
+## 5. Release Failure
+
+### Publish Abnormal Version
+In the publishing process there are often **cases of publishing failure**, such as the following image pulling failure:
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: echoserver
+...
+spec:
+  ...
+  containers:
+  - name: echoserver
+    # image not found
+    image: cilium/echoserver:failed
+    imagePullPolicy: IfNotPresent
+```
+At this point, the rollout status remains at **StepUpgrade** state, and by checking the deployment and pods status, you can see that it is because the image pull failed.
+
+![upgrade failed](../images/upgrade_failed.png)
+
+### a. Rollback To V1 Version
+The most common way is Rollback, where you don't need to do anything with the rollout crd,
+only just rollback the deployment configuration to the previous version, as follows **rollback the image version in deployment to 1.10.2 and kubectl apply -f to the k8s cluster**.
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: echoserver
+...
+spec:
+  ...
+  containers:
+  - name: echoserver
+    image: cilium/echoserver:1.10.2
+    imagePullPolicy: IfNotPresent
+```
+![rollback echoserver](../images/rollback_echoserver.png)
+
+### b. Continuous Release V3 Version
+For some scenarios where you can't rollback, you can continuously release the v3 version. as follows, **change the deployment image address to 1.10.3 and then kubectl apply -f to the k8s cluster**.
+Once the publishing is complete, just perform the **Approve Rollout** step.
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: echoserver
+...
+spec:
+  ...
+  containers:
+  - name: echoserver
+    image: cilium/echoserver:1.10.3
+    imagePullPolicy: IfNotPresent
+```
+![continuous release](../images/continuous_release.png)
+
+
+