Service Registry sample

Message Generation and Greeter are example applications demonstrating the use of Service Registry for Tanzu. (For information on the Service Registry product in Tanzu Application Service, please see the documentation.)

The main branch is using spring-boot 3.2.0 and spring-cloud 2023.0.0. Check spring-boot-2.7 branch for older versions.

Building and Deploying on Tanzu Application Platform (TAP)

Greeting with Service Registry on TAP has the following deployment architecture:

The eureka-controller manages a StatefulSet of eureka servers and connection Secrets that Greeter and Greeter Messages use to connect to discover each other.

Create a EurekaServer resource with two replicas using the provided YAML definition:
```
kubectl apply -f tap/eurekaserver.yaml
```

Check the status of the EurekaServer:

kubectl describe eurekaservers.service-registry.spring.apps.tanzu.vmware.com eurekaserver-sample -n my-apps

For example:

 k describe eurekaservers.service-registry.spring.apps.tanzu.vmware.com eurekaserver-sample
Name:         eurekaserver-sample
Namespace:    my-apps
Labels:       <none>
Annotations:  <none>
API Version:  service-registry.spring.apps.tanzu.vmware.com/v1alpha1
Kind:         EurekaServer
Metadata:
  Creation Timestamp:  2023-10-20T13:53:51Z
  Generation:          1
  Resource Version:    1727487
  UID:                 1c411573-281a-4ec1-b81e-65f746404ac8
Spec:
  Replicas:  2
Status:
  Binding:
    Name:  eureka-eurekaserver-sample-client-binding-z5tmh
  Conditions:
    Last Transition Time:  2023-10-20T13:53:57Z
    Message:               EurekaServer reconciled
    Observed Generation:   1
    Reason:                EurekaServerReconciled
    Status:                True
    Type:                  Ready
  Observed Generation:     1
  Server Binding:
    Name:  eureka-eurekaserver-sample-server-binding-m946r
Events:    <none>

A successful EurekaServer resource has a Ready condition set to true and a status.binding.name field pointing to a secret containing connection information.

Claim credentials using the Tanzu CLI:

tanzu service resource-claim create -n my-apps eurekaserver-sample \
    --resource-name eurekaserver-sample \
    --resource-kind EurekaServer \
    --resource-api-version service-registry.spring.apps.tanzu.vmware.com/v1alpha1 \
    --resource-namespace my-apps

Note	Alternatively the provided `ResourceClaim` yaml definition can be used: kubectl apply -f tap/resource-claim.yaml

Create workloads for both greeter and greeter-messages using the Tanzu CLI:

tanzu apps workload create -f tap/greeter-messages.yaml --yes
tanzu apps workload create -f tap/greeter.yaml --yes

Trying it Out

Retrieve the ingress route associated with the Greeter application using the tanzu cli:

tanzu apps workload get greeter

For example:

$ tanzu apps workload get greeter

# other output...

🚢 Knative Services
   NAME      READY   URL
   greeter   Ready   https://greeter.my-apps.tap

To see logs: "tanzu apps workload tail greeter --timestamp --since 1h"

Where https://greeter.my-apps.tap is the accessible ingress route to the greeter application

Visit [ROUTE]/hello, where [ROUTE] is the ingress route you just retrieved. The Greeter application will use the Service Registry to look up the Message Generation application and get a greeting message, which (to begin with) should be “Hello, Bob!”

You can see what the Message Generation application is sending back by viewing its logs, using tanzu apps workload tail greeter-messages:

$ tanzu apps workload tail greeter-messages

greeter-messages-579d67c498-bf6zl[workload] 2023-10-20T17:52:17.001Z  INFO 1 --- [nio-8080-exec-3] messages.MessagesController              : Now saying "Hi" to John

To get a different greeting message, you can provide salutation and name parameters, as in [ROUTE]/hello?salutation=Hi&name=John. The Greeter application will send those parameters to the Message Generation application and the resulting greeting will be customized to match.

For more information about the Service Registry and its use in a client application, see the Service Registry documentation.

Building and Deploying on Tanzu Application Service (TAS)

Build the two projects from the root (greeting) directory. If using Maven, run:
```
$ mvn package
```
If using Gradle, run ./gradlew build (OS X, Linux) or gradlew.bat build (Windows).
```
$ ./gradlew build
```
Run the deployment script (if you used Maven, scripts/deploy_mvn.sh or scripts/deploy_mvn.bat; if you used Gradle, scripts/deploy_gradle.sh or scripts/deploy_gradle.bat).
```
$ ./scripts/deploy_gradle.sh
```
The script will create a Service Registry service instance and then push the applications and bind them to the service.

Note	By default, the Spring Cloud Services Starters for Service Registry causes all application endpoints to be secured by HTTP Basic authentication. For more information or if you wish to disable this, see the documentation. (HTTP Basic authentication is disabled in these sample applications.)

Trying It Out

Visit [ROUTE]/hello, where [ROUTE] is the route bound to the Greeter application. The Greeter application will use the Service Registry to look up the Message Generation application and get a greeting message, which (to begin with) should be “Hello, Bob!”

You can see what the Message Generation application is sending back by viewing its logs. Run cf logs greeter-messages.

$ cf logs greeter-messages
Connected, tailing logs for app greeter-messages in org myorg / space development as user...

2015-07-16T13:07:35.86-0500 [App/0]      OUT 2015-07-16 18:07:35.861  INFO 29 ---
                     [o-61612-exec-10] greeter-messages.MessageGenerationApplication
                                                  : Now saying "Hello" to Bob
2015-07-16T13:07:35.87-0500 [RTR/0]      OUT greeter-messages.wise.com:80 -
                     [16/07/2015:18:07:35 +0000]
                     "GET /greeting?salutation=Hello&name=Bob HTTP/1.1" 200
                     31 "-" "Apache-HttpClient/4.3.6 (java 1.5)" 10.68.204.250:39929
                     x_forwarded_for:"10.68.204.43, 10.68.204.250"
                     vcap_request_id:66b782b6-9953-45b3-52ab-da369ad81f44
                     response_time:0.016146581
                     app_id:bd594ad5-2653-4949-afc6-e5f1ae568259

To get a different greeting message, you can provide salutation and name parameters, as in [ROUTE]/hello?salutation=Hi&name=John. The Greeter application will send those parameters to the Message Generation application and the resulting greeting will be customized to match.