The todo-backend quickstart demonstrates how to implement a backend that exposes a HTTP API with JAX-RS
to manage a list of ToDo which are persisted in a database with JPA.
This quickstart shows how to setup a local deployment of this backend as well as a deployment on OpenShift to connect to a PostgreSQL database also hosted on OpenShift.
The todo-backend quickstart demonstrates how to implement a backend that exposes a HTTP API with JAX-RS
to manage a list of ToDo which are persisted in a database with JPA.
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The backend exposes a HTTP API to manage a list of todos that complies with the specs defined at todobackend.com.
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It requires a connection to a PostgreSQL database to persist the todos.
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It uses the Server Provisioning for local and cloud deployment
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It can be build with WildFly S2I images for cloud deployment
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It is deployed on OpenShift using the Helm Chart for WildFly.
The application this project produces is designed to be run on WildFly Application Server 31 or later.
All you need to build this project is Java 11.0 (Java SDK 11) or later and Maven 3.6.0 or later. See Configure Maven to Build and Deploy the Quickstarts to make sure you are configured correctly for testing the quickstarts.
This backend is built using WildFly S2I Builder and Runtime images.
When the image is built, org.wildfly.plugins:wildfly-maven-plugin plugin provisions the WildFly application server and all the feature packs it needs for its features.
The layers are defined in the pom.xml file in the <configuration> section of the org.wildfly.plugins:wildfly-maven-plugin plugin:
<layers>
<layer>cloud-server</layer>
<layer>postgresql-datasource</layer>
</layers>The cloud-server layer provides everything needed to run the backend on OpenShift. This also includes access to
Jakarta EE APIs such as CDI, JAX-RS, JPA, etc. These two layers comes from the WildFly feature pack provided in the
WildFly S2I builder image.
The postgresql-datasource layer provides a JDBC driver and DataSource to connect to a PostgreSQL database. It is also provided by
org.wildfly:wildfly-datasources-galleon-pack which is included in the WildFly S2I image.
The Git repository for this feature pack is hosted at https://github.com/wildfly-extras/wildfly-datasources-galleon-pack.
It provides JDBC drivers and datasources for different databases but for this quickstart, we will only need the postgresql-datasource.
As mentioned, the JDBC drivers and datasource configuration that the backend uses to connect to the PostgreSQL database
is provided by the org.wildfly:wildfly-datasources-galleon-pack feature pack.
By default, it exposes a single datasource.
In the backend, the name of this datasource is ToDos and is specified in the persistence.xml to configure JPA:
<persistence-unit name="primary">
<jta-data-source>java:jboss/datasources/ToDos</jta-data-source>
</persistence-unit>At runtime, we only need a few environment variables to establish the connection from WildFly to the external PostgreSQL database:
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POSTGRESQL_DATABASE- the name of the database (that will be calledtodos) -
POSTGRESQL_SERVICE_HOST- the host to connect to the database -
POSTGRESQL_SERVICE_PORT- The port to connect to the database -
POSTGRESQL_USER&POSTGRESQL_PASSWORD- the credentials to connect to the database -
POSTGRESQL_DATASOURCE- The name of the datasources (as mentioned above, it will beToDos)
The Web frontend for this quickstart uses JavaScript calls to query the backend’s HTTP API.
We must enable Cross-Origin Resource Sharing (CORS) filters in the undertow subsystem of WildFly to allow
these HTTP requests to succeed.
This script is executed at build time and will provide the following HTTP headers to enabled CORS:
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Access-Control-Allow-Origin: * -
Access-Control-Allow-Methods: GET, POST, OPTION, PUT, DELETE, PATCH -
Access-Control-Allow-Headers: accept, authorization, content-type, x-requested-with -
Access-Control-Allow-Credentials: true -
Access-Control-Max-Age: 1
By default, the backend accepts requests from any origin (*). This is only simplicity. It is possible to restrict
the allowed origin using the environment variable CORS_ORIGIN at runtime.
The backend is packaged and deployed on a provisioned server:
$ mvn clean package -Pprovisioned-serverBefore running the backend locally, we need to have a local PostgreSQL database that we can connect to.
We use the postgresql docker image to create one:
$ docker run --name todo-backend-db -e POSTGRES_USER=todos -e POSTGRES_PASSWORD=mysecretpassword -p 5432:5432 postgresThis will create a database named todos that we can connect to on localhost:5432 with the credentials todos / mysecretpassword.
With the PostgreSQL database running, we can start the backend by passing the required environment variables to connect to the database:
$ ./target/server/bin/standalone.sh -Denv.POSTGRESQL_DATABASE=todos -Denv.POSTGRESQL_DATASOURCE=ToDos -Denv.POSTGRESQL_SERVICE_HOST=localhost -Denv.POSTGRESQL_SERVICE_PORT=5432 -Denv.POSTGRESQL_USER=todos -Denv.POSTGRESQL_PASSWORD=mysecretpasswordThe backend is running, and we can use the HTTP API to manage a list of todos:
# get a list of todos
$ curl http://localhost:8080
[]
# create a todo with the title "This is my first todo item!"
$ curl -X POST -H "Content-Type: application/json" -d '{"title": "This is my first todo item!"}' http://localhost:8080
{"completed":false,"id":1,"order":0,"title":"This is my first todo item!","url":"https://localhost:8080/1"}%
# get a list of todos with the one that was just created
$ curl http://localhost:8080
[{"completed":false,"id":1,"order":0,"title":"This is my first todo item!","url":"https://localhost:8080/1"}]The integration tests included with this quickstart, which verify that the quickstart runs correctly, may also be run with a provisioned server.
Follow these steps to run the integration tests.
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Make sure the server is provisioned.
$ mvn clean package -Pprovisioned-server -
Start the WildFly provisioned server, this time using the WildFly Maven Plugin, which is recommended for testing due to simpler automation. The path to the provisioned server should be specified using the
jbossHomesystem property.$ mvn wildfly:start -DjbossHome=target/server -DPOSTGRESQL_DATABASE=todos -DPOSTGRESQL_SERVICE_HOST=localhost -DPOSTGRESQL_SERVICE_PORT=5432 -DPOSTGRESQL_USER=todos -DPOSTGRESQL_PASSWORD=mysecretpassword -DPOSTGRESQL_DATASOURCE=ToDos -
Type the following command to run the
verifygoal with theintegration-testingprofile activated, and specifying the quickstart’s URL using theserver.hostsystem property, which for a provisioned server by default ishttp://localhost:8080.$ mvn verify -Pintegration-testing -Dserver.host=http://localhost:8080 -
Shutdown the WildFly provisioned server, this time using the WildFly Maven Plugin too.
$ mvn wildfly:shutdown
On OpenShift, the S2I build with Apache Maven uses an openshift Maven profile to provision a WildFly server, deploy and run the quickstart in OpenShift environment.
The server provisioning functionality is provided by the WildFly Maven Plugin, and you may find its configuration in the quickstart pom.xml:
<profile>
<id>openshift</id>
<build>
<plugins>
<plugin>
<groupId>org.wildfly.plugins</groupId>
<artifactId>wildfly-maven-plugin</artifactId>
<configuration>
<feature-packs>
<feature-pack>
<location>org.wildfly:wildfly-galleon-pack:${version.server}</location>
</feature-pack>
<feature-pack>
<location>org.wildfly.cloud:wildfly-cloud-galleon-pack:${version.pack.cloud}</location>
</feature-pack>
</feature-packs>
<layers>...</layers>
<name>ROOT.war</name>
</configuration>
<executions>
<execution>
<goals>
<goal>package</goal>
</goals>
</execution>
</executions>
</plugin>
...
</plugins>
</build>
</profile>You may note that unlike the provisioned-server profile it uses the cloud feature pack which enables a configuration tuned for OpenShift environment.
This section contains the basic instructions to build and deploy this quickstart to WildFly for OpenShift or WildFly for OpenShift Online using Helm Charts.
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You must be logged in OpenShift and have an
occlient to connect to OpenShift -
Helm must be installed to deploy the backend on OpenShift.
Once you have installed Helm, you need to add the repository that provides Helm Charts for WildFly.
$ helm repo add wildfly https://docs.wildfly.org/wildfly-charts/
"wildfly" has been added to your repositories
$ helm search repo wildfly
NAME CHART VERSION APP VERSION DESCRIPTION
wildfly/wildfly ... ... Build and Deploy WildFly applications on OpenShift
wildfly/wildfly-common ... ... A library chart for WildFly-based applicationsAdd the bitnami repository which provides an helm chart for PostgreSQL:
$ helm repo add bitnami https://charts.bitnami.com/bitnami
"bitnami" has been added to your repositoriesThe Helm Chart for this quickstart contains all the information to build an image from the source code using S2I and install it with the database:
dependencies:
- name: postgresql
repository: https://charts.bitnami.com/bitnami
version: ...
- name: wildfly
repository: http://docs.wildfly.org/wildfly-charts/
version: ...So we need to update the dependecies of our Helm Chart.
$ helm dependency update charts/Log in to your OpenShift instance using the oc login command.
The backend will be built and deployed on OpenShift with a Helm Chart for WildFly.
Navigate to the root directory of this quickstart and run the following command:
$ helm install todo-backend charts --wait --timeout=10m0s
NAME: todo-backend
...
STATUS: deployed
REVISION: 1This command will return once the application has successfully deployed. In case of a timeout, you can check the status of the application with the following command in another terminal:
oc get deployment todo-backendThe Helm Chart for this quickstart contains all the information to build an image from the source code using S2I on Java 17:
apiVersion: v2
name: todo-backend-chart
description: A Helm chart to deploy a WildFly todo-backend application and its Postgresql database
type: application
version: 1.0.0
appVersion: 31.0.0.Final
dependencies:
- name: postgresql
repository: https://charts.bitnami.com/bitnami
version: 13.1.5
- name: wildfly
repository: http://docs.wildfly.org/wildfly-charts/
version: 2.3.2This will create a new deployment on OpenShift and deploy the application.
If you want to see all the configuration elements to customize your deployment you can use the following command:
$ helm show readme wildfly/wildflyGet the URL of the route to the deployment.
$ oc get route todo-backend -o jsonpath="{.spec.host}"Access the application in your web browser using the displayed URL.
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Note
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The Maven profile named |
The integration tests included with this quickstart, which verify that the quickstart runs correctly, may also be run with the quickstart running on OpenShift.
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Note
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The integration tests expect a deployed application, so make sure you have deployed the quickstart on OpenShift before you begin. |
Run the integration tests using the following command to run the verify goal with the integration-testing profile activated and the proper URL:
$ mvn verify -Pintegration-testing -Dserver.host=https://$(oc get route todo-backend --template='{{ .spec.host }}') |
Note
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The tests are using SSL to connect to the quickstart running on OpenShift. So you need the certificates to be trusted by the machine the tests are run from. |
The Helm Chart also contains the environment variables required to connect to the PostgreSQL database.
In local deployment the credentials were passed directly as the values of the environment variables.
For OpenShift, we rely on secrets so that the credentials are never copied outside OpenShift:
deploy:
env:
- name: POSTGRESQL_PASSWORD
valueFrom:
secretKeyRef:
key: database-password
name: todo-backend-dbWhen the application is deployed, the value for the POSTGRESQL_PASSWORD will be taken from the key database-password
in the secret todo-backend-db.
The integration tests included with this quickstart, which verify that the quickstart runs correctly, may also be run with the quickstart running on OpenShift.
|
Note
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The integration tests expect a deployed application, so make sure you have deployed the quickstart on OpenShift before you begin. |
Run the integration tests using the following command to run the verify goal with the integration-testing profile activated and the proper URL:
$ mvn verify -Pintegration-testing -Dserver.host=https://$(oc get route todo-backend --template='{{ .spec.host }}') |
Note
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The tests are using SSL to connect to the quickstart running on OpenShift. So you need the certificates to be trusted by the machine the tests are run from. |
Once the backend is deployed on OpenShift, it can be accessed from the route todo-backend.
Let’s find the host that we can use to connect to this backend:
$ oc get route todo-backend -o jsonpath="{.spec.host}"
todo-backend-jmesnil1-dev.apps.sandbox.x8i5.p1.openshiftapps.comThis value will be different for every installation of the backend.
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Warning
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Make sure to prepend the host with |
We can verify that this application is properly working as a ToDo Backend by running its specs on it.
Once all tests passed, we can use the todobackend client to have a Web application connected to the backend.
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Note
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todobackend.com is an external service used to showcase this quickstart. It might not always be functional but does not impact the availability of this backend. |
This quickstart shows how the datasource feature pack provided by WildFly simplifies the deployment of a WildFly Jakarta EE backend on OpenShift to connect to an external database and exposes an HTTP API.
The use of a Server Provisioned deployment makes it seamless to move from a local deployment for development to a deployment on OpenShift.