Introduce sample application (spring-petclinic + postgresql) to be used in quickstart

[pmacik]

Motivation

Current quickstart uses only REST API server part of the Spring Petclinic as an application and Crunchy Postgresql Operator backed DB. It has couple of UX issues.

The current application:

• does not have UI so user must use kubectl port-forward and curl command to send requests to the application's API server and analyze responses for accessing and verifying that the application works as expected
• user has to manually run a script to initialize database with application schema and data (as one of the quickstart's steps)

The current database:

• requires installation of Crunchy Postgresql Operator (via OLM) that wouldn't be possible for user with kubernetes cluster without OLM
• uses an operator that is not available on other then x86_64 architectures, which excludes all users on alternative architectures

Changes

This PR:

• Introduces an alternative Sprint Petclinic application that improves UX:
  • has a UI for user to interact with
  • initializes database schema and data automatically, so user does not to do it manually - thus simlify the quickstart scenario
  • is based on https://github.com/spring-projects/spring-petclinic application enhanced by https://github.com/spring-cloud/spring-cloud-bindings library.
  • is multi-arch
• Introduces an alternative PostgreSQL deployment that:
  • is in a for of plain Deployment based on postgres:13 image that is multi-arch
  • does not require OLM
• Both app and db including binding is tested on minikube and openshift clusters
• Is followed-up by Refactor getting started guide to use the sample spring-petclinic  #1085
  • These app and db deployments are supposed to replace the ones used in SBO's quickstart eventually.

Testing

The following steps involve running some convenient Makefile targets that serve here only to ease testing and will be replaced by the actual kubectl or oc commands and explained in the quickstart, eventually.

0. Set your environment

   • with minikube (default)
     export KUBERNETES_RUNTIME=minikube
   • with OpenShift
     export KUBERNETES_RUNTIME=openshift

1. Go to samples/app/spring-petclinic directory
   cd samples/app/spring-petclinic

2. Create user namespace (my-postgresql by default)
   make namespace

3. Deploy database Deployment
   make deploy-database

4. Expose DB binding data by setting annotations on database Deployment
   make annotate-database

5. Deploy application Deployment
   make deploy-app
   URL for the application UI is printed out so open it to access the application, but application's pod is stuck in Init state due unavailable DB.

6. Bind application to db
   make bind

7. After the application pod is restarted, the application's pod is Running UI should show the web interface.

[pmacik]

@yselkowitz could you please take a look in terms of multi-arch?
Especially the two application images to be built from included Dockerfiles

Thanks

[codecov]

Codecov Report

Merging #1080 (33e9946) into master (36f271e) will not change coverage.
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@@           Coverage Diff           @@
##           master    #1080   +/-   ##
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  Coverage   58.92%   58.92%           
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  Files          30       30           
  Lines        1670     1670           
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  Hits          984      984           
  Misses        560      560           
  Partials      126      126           

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[pmacik]

/retest

[pedjak]

additionally, please avoid folder names starting with a dot, e.g. .minikube, .openshift.. they are hidden by default from shell and this can create some confusions.

[pedjak]

the rest of the project uses kustomize, so if really needed we could use that instead of sed

[pmacik]

/retest

[pmacik]

Sent a pull-request spring-projects/spring-petclinic#887 to enable spring cloud bindings in the petclinic application to avoid the need of patching the app source while building the app container.

[pmacik]

/retest

[pedjak]

/lgtm

[baijum]

/lgtm

[pedjak]

/approve

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pedjak

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[pedjak]

/lgtm

[openshift-ci]

@pmacik: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/4.10-acceptance	1a681b6	link	true	/test 4.10-acceptance

Full PR test history. Your PR dashboard.

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[pmacik]

The Bind test application to Postgres instance provisioned by Cloud Native Postgres operator test fails for OpenShift 4.10 because the Cloud Native Postgres operator is not available in 4.10 catalog.