The prototype developed within this projects aims to resolve the following user's stories.
"As a user, I want to install a pod running my runtime Java Application (Spring Boot, Vert.x, Swarm) where my endpoint is exposed as a Service accessible via a route, where I can instruct the pod to start or stop a command such as "compile", "run java", ..." within the pod"
"As a user, I want to customize the application deployed using a MANIFEST yaml file where I can specify, the name of the application, s2i image to be used, maven tool, port of the service, cpu, memory, ...."
"As a user, I would like to know according to the OpenShift platform, which version of the template/builder and which resources are processed when it will be installed/deployed"
The following chapter describes how we have technically implemented such user stories:
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pod of the application/component (created by odo) defined with a :
- initContainer : supervisord [2] where different commands are registered from ENV vars. E.g. start/stop the java runtime, debug or compile (= maven), ...
- container : created using Java S2I image
- shared volume
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commands can be executed remotely to trigger and action within the developer's pod -> supervisord ctl start|stop program1,....,programN
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OpenShift Template -> converted into individual yaml files (= builder concept) and containing "{{.key}} to be processed by the go template engine
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Developer's user preferences are stored into a MANIFEST yaml (as Cloudfoundry proposes too) which is parsed at bootstrap to create an "Application" struct object used next to process the template and replace the keys with their values
- Go Lang : >=1.9
- GOWORKSPACE variable defined
- oc Client Tools
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Install the project within your
$GOPATH's workspacecd $GOPATH/src go get github.com/cmoulliard/k8s-supervisor cd k8s-supervisor
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Build the project locally
go build -o sb *.go export PATH=$(pwd):$PATH
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Create the
k8s-supervisordnamespace on OpenShiftoc new-project k8s-supervisord
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Move to the
spring-bootfoldercd spring-boot -
Initialize your application, optionally passing the following parameters:
-k | --kubeconfig: /PATH/TO/KUBE/CONFIG-n | --namespace: OpenShift project-a | --application: application name
sb init -a spring-boot-http
Here, we initialized a
spring-boot-httpapplication. This name will be used to create OpenShift resources and set up the environment. -
Verify if the
initContainerhas been injected within thespring-boot-http(the name you chose for your application)DeploymentConfigoc get dc/spring-boot-http -o jsonpath='{.spec.template.spec.initContainers[0].name}{"\n"}'This should yield
copy-supervisordif everything is properly set up.
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As the development pod has been created and is running the
supervisordserver, we will now push the code. -
if we want to compile the project using maven within the pod, then we will copy the following resources within the pod :
pom.xml, src/ folderIn this case, use the following commandsb push --mode source -
To use your generated
uberjarfile located under/target/application-name-version.jar, then run this command :sb push --mode binary
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Compile the code source pushed within the pod using this command
sb compile INFO[0000] sb Compile command called INFO[0000] [Step 1] - Parse MANIFEST of the project if it exists INFO[0000] [Step 2] - Get K8s config file INFO[0000] [Step 3] - Create kube Rest config client using config's file of the developer's machine INFO[0000] [Step 4] - Wait till the dev's pod is available INFO[0000] [Step 5] - Compile ... compile-java: started time="2018-07-13T10:59:05Z" level=info msg="create process:run-java" time="2018-07-13T10:59:05Z" level=info msg="create process:compile-java" time="2018-07-13T10:59:05Z" level=info msg="create process:build" time="2018-07-13T10:59:05Z" level=info msg="create process:echo" time="2018-07-13T11:03:39Z" level=debug msg="no auth required" time="2018-07-13T11:03:39Z" level=debug msg="succeed to find process:compile-java" time="2018-07-13T11:03:39Z" level=info msg="try to start program" program=compile-java time="2018-07-13T11:03:39Z" level=info msg="success to start program" program=compile-java ================================================================== Starting S2I Java Build ..... Maven build detected Initialising default settings /tmp/artifacts/configuration/settings.xml Setting MAVEN_OPTS to -XX:+UnlockExperimentalVMOptions -XX:+UseCGroupMemoryLimitForHeap -XX:+UseParallelOldGC -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=20 -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -XX:MaxMetaspaceSize=100m -XX:+ExitOnOutOfMemoryError Found pom.xml ... Running 'mvn -Dmaven.repo.local=/tmp/artifacts/m2 -s /tmp/artifacts/configuration/settings.xml -e -Popenshift -DskipTests -Dcom.redhat.xpaas.repo.redhatga -Dfabric8.skip=true package --batch-mode -Djava.net.preferIPv4Stack=true ' Apache Maven 3.5.0 (Red Hat 3.5.0-4.3) Maven home: /opt/rh/rh-maven35/root/usr/share/maven Java version: 1.8.0_171, vendor: Oracle Corporation Java home: /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.171-8.b10.el7_5.x86_64/jre Default locale: en_US, platform encoding: ANSI_X3.4-1968 OS name: "linux", version: "3.10.0-693.21.1.el7.x86_64", arch: "amd64", family: "unix" time="2018-07-13T11:03:40Z" level=debug msg="wait program exit" program=compile-java [INFO] Error stacktraces are turned on. [INFO] Scanning for projects... [INFO] Downloading: https://repo1.maven.org/maven2/io/openshift/booster-parent/23/booster-parent-23.pom ... [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 01:07 min [INFO] Finished at: 2018-07-13T11:04:49Z [INFO] Final Memory: 26M/40M [INFO] ------------------------------------------------------------------------ [WARNING] The requested profile "openshift" could not be activated because it does not exist. Copying Maven artifacts from /tmp/src/target to /deployments ... Running: cp *.jar /deployments ... done time="2018-07-13T11:04:49Z" level=info msg="program stopped with status:exit status 0" program=compile-java time="2018-07-13T11:04:49Z" level=info msg="Don't start the stopped program because its autorestart flag is false" program=compile-java
Remark Before to launch the compilation's command using supervisord, the program will wait till the development's pod is alive !
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Launch the Spring Boot Application
sb exec start ime="2018-07-13T11:06:26Z" level=debug msg="succeed to find process:run-java" time="2018-07-13T11:06:26Z" level=info msg="try to start program" program=run-java time="2018-07-13T11:06:26Z" level=info msg="success to start program" program=run-java Starting the Java application using /opt/run-java/run-java.sh ... exec java -javaagent:/opt/jolokia/jolokia.jar=config=/opt/jolokia/etc/jolokia.properties -XX:+UnlockExperimentalVMOptions -XX:+UseCGroupMemoryLimitForHeap -XX:+UseParallelOldGC -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=20 -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -XX:MaxMetaspaceSize=100m -XX:+ExitOnOutOfMemoryError -cp . -jar /deployments/spring-boot-http-1.0.jar time="2018-07-13T11:06:27Z" level=debug msg="wait program exit" program=run-java I> No access restrictor found, access to any MBean is allowed Jolokia: Agent started with URL https://172.17.0.7:8778/jolokia/ . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v1.5.14.RELEASE) ... 2018-07-13 11:06:34.293 INFO 222 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup 2018-07-13 11:06:34.304 INFO 222 --- [ main] o.s.c.support.DefaultLifecycleProcessor : Starting beans in phase 0 2018-07-13 11:06:34.427 INFO 222 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http) 2018-07-13 11:06:34.436 INFO 222 --- [ main] io.openshift.booster.BoosterApplication : Started BoosterApplication in 6.412 seconds (JVM running for 7.32)
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Access the endpoint of the Spring Boot application using curl
URL="http://$(oc get routes/spring-boot-http -o jsonpath='{.spec.host}')" curl $URL/api/greeting {"content":"Hello, World!"}%
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You can also debug your application by forwarding the traffic between the pod and your machine using the following command :
sb debug INFO[0000] sb exec start command called INFO[0000] [Step 1] - Parse MANIFEST of the project if it exists INFO[0000] [Step 2] - Get K8s config file INFO[0000] [Step 3] - Create kube Rest config client using config's file of the developer's machine INFO[0000] [Step 4] - Wait till the dev's pod is available INFO[0000] [Step 5] - Restart Java Application run-java: stopped run-java: started INFO[0003] [Step 6] - Remote Debug the spring Boot Application ... Forwarding from 127.0.0.1:5005 -> 5005
Remark : You can change the local/remote ports to be used by passing the parameter
-p. E.gsb debug -p 9009:9009
- The Spring Boot Application can be stopped, started or restarted using respectively these commands:
sb exec stop sb exec start sb exec restart
oc delete --force --grace-period=0 all --all
oc delete pvc/m2-data