Appendix A. S2I scripts and Maven
The Red Hat JBoss Web Server for OpenShift image includes S2I scripts and Maven.
A.1. Maven artifact repository mirrors and JWS for OpenShift
A Maven repository holds build artifacts and dependencies, such as the project Java archive (JAR) files, library JAR files, plugins or any other project-specific artifacts. A Maven repository also defines locations that you can download artifacts from while performing the source-to-image (S2I) build. In addition to using the Maven Central Repository, some organizations also deploy a local custom repository (mirror).
A local mirror provides the following benefits:
- Availability of a synchronized mirror that is geographically closer and faster
- Greater control over the repository content
- Possibility to share artifacts across different teams (developers and continuous integration (CI)) without relying on public servers and repositories
- Improved build times
A Maven repository manager can serve as local cache to a mirror. If the repository manager is already deployed and can be reached externally at a specified URL location, the S2I build can use this repository. You can use an internal Maven repository by adding the MAVEN_MIRROR_URL
environment variable to the build configuration of the application.
Additional resources
A.1.1. Using an internal Maven repository for a new build configuration
You can add the MAVEN_MIRROR_URL
environment variable to a new build configuration of your application, by specifying the --build-env
option with the oc new-app
command or the oc new-build
command.
Procedure
Enter the following command:
$ oc new-app \ https://github.com/web-servers/tomcat-websocket-chat-quickstart.git#main \ --image-stream=jboss-webserver58-openjdk8-tomcat9-openshift-ubi8:latest \ --context-dir='tomcat-websocket-chat' \ --build-env MAVEN_MIRROR_URL=http://10.0.0.1:8080/repository/internal/ \ --name=jws-wsch-app
NoteThe preceding command assumes that the repository manager is already deployed and can be reached at
http://10.0.0.1:8080/repository/internal/
.
A.1.2. Using an internal Maven repository for an existing build configuration
You can add the MAVEN_MIRROR_URL
environment variable to an existing build configuration of your application, by specifying the name of the build configuration with the oc set env
command.
Procedure
Identify the build configuration that requires the
MAVEN_MIRROR_URL
variable:$ oc get bc -o name
The preceding command produces the following type of output:
buildconfig/jws
NoteIn the preceding example, jws is the name of the build configuration.
Add the
MAVEN_MIRROR_URL
environment variable tobuildconfig/jws
:$ oc set env bc/jws MAVEN_MIRROR_URL="http://10.0.0.1:8080/repository/internal/" buildconfig "jws" updated
Verify the build configuration has updated:
$ oc set env bc/jws --list # buildconfigs jws MAVEN_MIRROR_URL=http://10.0.0.1:8080/repository/internal/
-
Schedule a new build of the application by using
oc start-build
During the application build process, Maven dependencies are downloaded from the repository manager rather than from the default public repositories. When the build process is completed, the mirror contains all the dependencies that are retrieved and used during the build process.
A.2. Scripts included on the Red Hat JBoss Web Server for OpenShift image
The Red Hat JBoss Web Server for OpenShift image includes scripts to run Catalina and to use Maven to create and deploy the .war
package.
run
- Runs Catalina (Tomcat)
assemble
-
Uses Maven to build the web application source, create the
.war
file, and move the.war
file to the$JWS_HOME/tomcat/webapps
directory.
A.3. JWS for OpenShift datasources
JWS for OpenShift provides three type of data sources:
- Default internal data sources
-
PostgreSQL, MySQL, and MongoDB data sources are available on OpenShift by default through the Red Hat Registry. These data sources do not require additional environment files to be configured for image streams. To enable a database to be discovered and used as a data source, you can set the
DB_SERVICE_PREFIX_MAPPING
environment variable to the name of the OpenShift service. - Other internal data sources
- These data sources are run on OpenShift but they are not available by default through the Red Hat Registry. Environment files that are added to OpenShift Secrets provide configuration of other internal data sources.
- External data sources
- These data sources are not run on OpenShift. Environment files that are added to OpenShift Secrets provide configuration of external data sources.
ENV_FILES
property
You can add the environment variables for data sources to the OpenShift Secret for the project. You can use the ENV_FILES
property to call these environment files within the template.
DB_SERVICE_PREFIX_MAPPING
environment variable
Data sources are automatically created based on the value of certain environment variables. The DB_SERVICE_PREFIX_MAPPING
environment variable defines JNDI mappings for the data sources.
The allowed value for the DB_SERVICE_PREFIX_MAPPING
variable is a comma-separated list of POOLNAME-DATABASETYPE=PREFIX
triplets. Each triplet consists of the following values:
-
POOLNAME
is used as thepool-name
in the data source. -
DATABASETYPE
is the database driver to use. -
PREFIX
is the prefix in the names of environment variables that are used to configure the data source.
For each POOLNAME-DATABASETYPE=PREFIX
triplet that is defined in the DB_SERVICE_PREFIX_MAPPING
environment variable, the launch script creates a separate data source, which is executed when running the image.
Additional resources
A.4. JWS for OpenShift compatible environment variables
You can modify the build configuration by including environment variables with the source-to-image (S2I) build
command. For more information, see Maven artifact repository mirrors and JWS for OpenShift.
The following table lists the valid environment variables for the Red Hat JBoss Web Server for OpenShift images:
Variable Name | Display Name | Description | Example Value |
---|---|---|---|
ARTIFACT_DIR | N/A |
| target |
APPLICATION_NAME | Application Name | The name for the application | jws-app |
CONTEXT_DIR | Context Directory | Path within Git project to build; empty for root project directory | tomcat-websocket-chat |
GITHUB_WEBHOOK_SECRET | Github Webhook Secret | Github trigger secret | Expression from: [a-zA-Z0-9]{8} |
GENERIC_WEBHOOK_SECRET | Generic Webhook Secret | Generic build trigger secret | Expression from: [a-zA-Z0-9]{8} |
HOSTNAME_HTTP | Custom HTTP Route Hostname | Custom hostname for http service route. Leave blank for default hostname | <application-name>-<project>.<default-domain-suffix> |
HOSTNAME_HTTPS | Custom HTTPS Route Hostname | Custom hostname for https service route. Leave blank for default hostname | <application-name>-<project>.<default-domain-suffix> |
IMAGE_STREAM_NAMESPACE | Imagestream Namespace | Namespace in which the ImageStreams for Red Hat Middleware images are installed | openshift |
JWS_HTTPS_SECRET | Secret Name | The name of the secret containing the certificate files | jws-app-secret |
JWS_HTTPS_CERTIFICATE | Certificate Name | The name of the certificate file within the secret | server.crt |
JWS_HTTPS_CERTIFICATE_KEY | Certificate Key Name | The name of the certificate key file within the secret | server.key |
JWS_HTTPS_CERTIFICATE_PASSWORD | Certificate Password | The Certificate Password | P5ssw0rd |
SOURCE_REPOSITORY_URL | Git Repository URL | Git source URI for Application | https://github.com/web-servers/tomcat-websocket-chat-quickstart.git |
SOURCE_REPOSITORY_REFERENCE | Git Reference | Git branch/tag reference | 1.2 |
IMAGE_STREAM_NAMESPACE | Imagestream Namespace | Namespace in which the ImageStreams for Red Hat Middleware images are installed | openshift |
MAVEN_MIRROR_URL | Maven Mirror URL | URL of a Maven mirror/repository manager to configure. | http://10.0.0.1:8080/repository/internal/ |