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improve blue/green demo doc (#226)

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Kent Rancourt 2018-07-20 18:14:33 -04:00 committed by Google Prow Robot
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serving/samples/blue-green-deployment.md
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@ -11,28 +11,18 @@ You need:
* A Kubernetes cluster with [Knative installed](../install/README.md).
* (Optional) [A custom domain configured](../serving/using-a-custom-domain.md) for use with Knative.
## Deploying Version 1 (Blue)
## Deploying Revision 1 (Blue)
We'll be deploying an image of a sample application that displays the text
"App v1" on a blue background.
First, create a new file called `stage1.yaml`and copy this into it:
First, create a new file called `blue-green-demo-config.yaml`and copy this into it:
```yaml
apiVersion: serving.knative.dev/v1alpha1
kind: Route
metadata:
name: route-demo # The name of our route; appears in the URL to access the app
namespace: default # The namespace we're working in; also appears in the URL to access the app
spec:
traffic:
- configurationName: route-demo-config-v1
percent: 100 # All traffic goes to this configutation
---
apiVersion: serving.knative.dev/v1alpha1
kind: Configuration
metadata:
name: route-demo-config-v1
name: blue-green-demo
namespace: default
spec:
revisionTemplate:
@ -41,29 +31,51 @@ spec:
knative.dev/type: container
spec:
container:
image: gcr.io/knative-samples/knative-route-demo:blue # The URL to the sample app
image: gcr.io/knative-samples/knative-route-demo:blue # The URL to the sample app docker image
imagePullPolicy: Always
env:
- name: T_VERSION
value: "blue"
```
Save the file, then deploy the application to your cluster:
Save the file, then deploy the configuration to your cluster:
```bash
kubectl apply -f stage1.yaml
kubectl apply -f blue-green-demo-config.yaml
route "route-demo" configured
configuration "route-demo-config-v1" configured
configuration "blue-green-demo" configured
```
This will deploy the initial revision (`blue-green-demo-00001`) of the sample
application. To route inbound traffic to it, we'll define a route. Create a new
file called `blue-green-demo-route.yaml` and copy this into it:
```yaml
apiVersion: serving.knative.dev/v1alpha1
kind: Route
metadata:
name: blue-green-demo # The name of our route; appears in the URL to access the app
namespace: default # The namespace we're working in; also appears in the URL to access the app
spec:
traffic:
- revisionName: blue-green-demo-00001
percent: 100 # All traffic goes to this revision
```
Save the file, then apply the route to your cluster:
```bash
kubectl apply -f blue-green-demo-route.yaml
route "blue-green-demo" configured
```
You'll now be able to view the sample app at
http://route-demo.default.YOUR_CUSTOM_DOMAIN.com (replace `YOUR_CUSTOM_DOMAIN`)
http://blue-green-demo.default.YOUR_CUSTOM_DOMAIN.com (replace `YOUR_CUSTOM_DOMAIN`)
with the [custom domain](../serving/using-a-custom-domain.md) you configured for
use with Knative.
> Note: If you don't have a custom domain configured for use with Knative, you can interact
with your app using cURL requests if you have the host URL and IP address:
`curl -H "Host: route-demo.default.example.com" http://IP_ADDRESS`
`curl -H "Host: blue-green-demo.default.example.com" http://IP_ADDRESS`
Knative creates the host URL by combining the name of your Route object,
the namespace, and `example.com`, if you haven't configured a custom domain.
For example, `[route-name].[namespace].example.com`.
@ -72,30 +84,17 @@ use with Knative.
See [Interacting with your app](../install/getting-started-knative-app.md#interacting-with-your-app)
for more information.
## Deploying Version 2 (Green)
## Deploying Revision 2 (Green)
Version 2 of the sample application displays the text "App v2" on a green background.
Create a new file called `stage2.yaml` and copy this into it:
Revision 2 of the sample application will display the text "App v2" on a green background.
To create the new revision, we'll edit our existing configuration in
`blue-green-demo-config.yaml` with an updated image and environment variables:
```yaml
apiVersion: serving.knative.dev/v1alpha1
kind: Route
kind: Configuration
metadata:
name: route-demo # Route name is unchanged, since we're updating an existing Route
namespace: default
spec:
traffic:
- configurationName: route-demo-config-v1
percent: 100 # All traffic still going to the first version
- configurationName: route-demo-config-v2
percent: 0
name: v2
---
apiVersion: serving.knative.dev/v1alpha1
kind: Configuration # Adding a new Configuration for the second app version
metadata:
name: route-demo-config-v2
name: blue-green-demo # Configuration name is unchanged, since we're updating an existing Configuration
namespace: default
spec:
revisionTemplate:
@ -104,62 +103,84 @@ spec:
knative.dev/type: container
spec:
container:
image: gcr.io/knative-samples/knative-route-demo:green # URL to the second version of the app
image: gcr.io/knative-samples/knative-route-demo:green # URL to the new version of the sample app docker image
imagePullPolicy: Always
env:
- name: T_VERSION
value: "green"
value: "green" # Updated value for the T_VERSION environment variable
```
This updates the existing Route's configuration to add the second configuration,
and adds the Configuration for the second version of the app. We start with zero
percent of traffic routed to Version 2.
Save the file, then deploy the application to your cluster:
Save the file, then apply the updated configuration to your cluster:
```bash
kubectl apply -f stage2.yaml
kubectl apply -f blue-green-demo-config.yaml
route "route-demo" configured
configuration "route-demo-config-v2" configured
configuration "blue-green-demo" configured
```
Version 2 of the app is staged at this point. That means:
* No traffic will be routed to version 2 at the main URL, http://route-demo.default.YOUR_CUSTOM_DOMAIN.com
* Knative creates a new route named v2 for testing the newly deployed version at http://v2.route-demo.default.YOUR_CUSTOM_DOMAIN.com
This allows you to validate that the new version of the app is behaving as expected before switching
any traffic over to it.
## Migrating traffic to the new version
Create a new file called `stage3.yaml` and copy this into it:
At this point, the first revision (`blue-green-demo-00001`) and the second
revision (`blue-green-demo-00002`) will both be deployed and running. We can
update our existing route to create a new (test) endpoint for the second
revision while still sending all other traffic to the first revision. Edit
`blue-green-demo-route.yaml`:
```yaml
apiVersion: serving.knative.dev/v1alpha1
kind: Route
metadata:
name: route-demo # Updating our existing route
name: blue-green-demo # Route name is unchanged, since we're updating an existing Route
namespace: default
spec:
traffic:
- configurationName: route-demo-config-v1
- revisionName: blue-green-demo-00001
percent: 100 # All traffic still going to the first revision
- revisionName: blue-green-demo-00002
percent: 0 # 50% of traffic routed to the second revision
name: v2 # A named route
```
Save the file, then apply the updated route to your cluster:
```bash
kubectl apply -f blue-green-demo-route.yaml
route "blue-green-demo" configured
```
Revision 2 of the app is staged at this point. That means:
* No traffic will be routed to revision 2 at the main URL, http://blue-green-demo.default.YOUR_CUSTOM_DOMAIN.com
* Knative creates a new route named v2 for testing the newly deployed version at http://v2.blue-green-demo.default.YOUR_CUSTOM_DOMAIN.com
This allows you to validate that the new version of the app is behaving as expected before switching
any traffic over to it.
## Migrating traffic to the new revision
We'll once again update our existing route to begin shifting traffic away from
the first revision and toward the second. Edit `blue-green-demo-route.yaml`:
```yaml
apiVersion: serving.knative.dev/v1alpha1
kind: Route
metadata:
name: blue-green-demo # Updating our existing route
namespace: default
spec:
traffic:
- revisionName: blue-green-demo-00001
percent: 50 # Updating the percentage from 100 to 50
- configurationName: route-demo-config-v2
- revisionName: blue-green-demo-00002
percent: 50 # Updating the percentage from 0 to 50
name: v2
```
Save the file, then deploy the updated routing configuration to your cluster:
Save the file, then apply the updated route to your cluster:
```bash
kubectl apply -f stage3.yaml
kubectl apply -f blue-green-demo-route.yaml
route "route-demo" configured
route "blue-green-demo" configured
```
Refresh the original route (http://route-demo.default.YOUR_CUSTOM_DOMAIN.com) a
Refresh the original route (http://blue-green-demo.default.YOUR_CUSTOM_DOMAIN.com) a
few times to see that some traffic now goes to version 2 of the app.
> Note: This sample shows a 50/50 split to assure you don't have to refresh too much,
@ -168,45 +189,49 @@ few times to see that some traffic now goes to version 2 of the app.
## Rerouting all traffic to the new version
Create a new file called `stage4.yaml` and copy this into it:
Lastly, we'll update our existing route to finally shift all traffic to the
second revision. Edit `blue-green-demo-route.yaml`:
```yaml
apiVersion: serving.knative.dev/v1alpha1
kind: Route
metadata:
name: route-demo # Updating our existing route
name: blue-green-demo # Updating our existing route
namespace: default
spec:
traffic:
- configurationName: route-demo-config-v1
- revisionName: blue-green-demo-00001
percent: 0
name: v1 # Adding a new named route for v1
- configurationName: route-demo-config-v2
- revisionName: blue-green-demo-00002
percent: 100
# Named route for v2 has been removed, since we don't need it anymore
```
Save the file, then deploy the updated routing configuration to your cluster:
Save the file, then apply the updated route to your cluster:
```bash
kubectl apply -f stage4.yaml
kubectl apply -f blue-green-demo-route.yaml
route "route-demo" configured
route "blue-green-demo" configured
```
Refresh the original route (http://route-demo.default.YOUR_CUSTOM_DOMAIN.com) a
Refresh the original route (http://blue-green-demo.default.YOUR_CUSTOM_DOMAIN.com) a
few times to verify that no traffic is being routed to v1 of the app.
We added a named route to v1 of the app, so you can now access it at
http://v1.route-demo.default.YOUR_CUSTOM_DOMAIN.com.
http://v1.blue-green-demo.default.YOUR_CUSTOM_DOMAIN.com.
With all inbound traffic being directed to the second revision of the
application, Knative will soon scale the first revision down to 0 running pods
and the blue/green deployment can be considered complete. Using the named `v1`
route will reactivate a pod to serve any occassional requests intended
specifically for the initial revision.
## Cleaning up
To delete the sample app, enter the following commands:
```
kubectl delete -f stage4.yaml --ignore-not-found=true
kubectl delete -f stage3.yaml --ignore-not-found=true
kubectl delete -f stage2.yaml --ignore-not-found=true
kubectl delete -f stage1.yaml --ignore-not-found=true
kubectl delete route blue-green-demo
kubectl delete configuration blue-green-demo
```