The fabric8 kubernetes Java & Scala client API is great for talking to kubernetes (or OpenShift), but its documentation is very sparse. What is a code example for adding resource requirements to containers running in a kubernetes pod?
if(EmptyUtil.isNotNull(template.getComputeRequest()) ||
EmptyUtil.isNotNull(template.getComputeLimit())) {
containerBuilder.withResources(buildResources(template.getComputeRequest(), template.getComputeLimit()));
}
private ResourceRequirements buildResources(InstanceType request, InstanceType limit){
_logger.info("Building computeResources");
ResourceRequirementsBuilder requirementsBuilder = new ResourceRequirementsBuilder(isValidationEnabled);
if(EmptyUtil.isNotNull(request)){
requirementsBuilder.withRequests(K8ComputeResourceUtil.buildCompute(request));
}
if(EmptyUtil.isNotNull(limit)){
requirementsBuilder.withLimits(K8ComputeResourceUtil.buildCompute(limit));
}
return requirementsBuilder.build();
}
public static Map<String, Quantity> buildCompute(InstanceType compute){
Map<String, Quantity> computeResourceMap = new HashMap<>();
if(EmptyUtil.isNotNull(compute.getCpu())) {
computeResourceMap.putAll(buildCpu(compute.getCpu()));
}
if(EmptyUtil.isNotNull(compute.getMemory())) {
computeResourceMap.putAll(buildMemory(compute.getMemory()));
}
return computeResourceMap;
}
private static Map<String, Quantity> buildCpu(Float cpu){
Map<String, Quantity> cpuMap = new HashMap<>();
try {
Quantity cpuQuantity = new Quantity();
if (EmptyUtil.isNotNull(cpu)) {
cpuQuantity.setAmount(String.valueOf(cpu));
cpuMap.put(K8Constants.CPU, cpuQuantity);
}
} catch (NumberFormatException nfe){
_logger.error("Failed to convert cpu '{}'", cpu, nfe);
}
return cpuMap;
}
private static Map<String, Quantity> buildMemory(Integer memory){
Map<String, Quantity> cpuMap = new HashMap<>();
try {
Quantity cpu = new Quantity();
if (EmptyUtil.isNotNull(memory)) {
cpu.setAmount(String.valueOf(memory));
cpuMap.put(K8Constants.MEMORY, cpu);
}
} catch (NumberFormatException nfe){
_logger.error("Failed to convert memory '{}'", memory, nfe);
}
return cpuMap;
}
Here I have some builders to build cpu and memory. This is just to understand the flow. You can give cpu/memory value in integer or string.
If you are using the fabric8 kubernetes-client API for Java and Scala, here is a snippet of code that demonstrates how to add resource requirements to a container running in a pod. This code was copied from Scala, but Java code would be very similar:
// other fabric8 imports not included; just focusing on resource
// requirements logic in this example
import io.fabric8.kubernetes.api.model.Quantity
import io.fabric8.kubernetes.api.model.ResourceRequirementsBuilder
// Use Java style Map (as opposed to Scala's Map class)
val reqMap: java.util.Map[String, Quantity] =
new java.util.HashMap[String, Quantity]()
// add CPU and memory requirements to the map
reqMap.put("cpu", new Quantity("1"))
reqMap.put("memory", new Quantity("1500Mi"))
// Build a ResourceRequirements object from the map
val reqs = new ResourceRequirementsBuilder()
.withRequests(reqMap)
.build()
// pass the ResourceRequirements object to the container spec
val pod = new PodBuilder()
.withNewMetadata()
.withName(podName)
.endMetadata()
.withNewSpec()
.withRestartPolicy("OnFailure")
.addNewContainer()
.withName(containerName)
.withImage(containerImage)
.withImagePullPolicy("Always")
.withResources(reqs) // <-- resource reqs here
.withCommand(commandName)
.withArgs(commandArguments)
.endContainer()
.endSpec()
.build()
// create the new pod with resource requirements via the
// fabric8 kube client:
client.pods().inNamespace(nameSpace).withName(podName).create(pod)