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Container Manager

Description

The Container Manager in Chaos Engine is designed to cache information about containers and prevent the need for recreating them repeatedly. Since we expect most containers to have a relatively long life cycle, we should prevent recreating objects every time we scan the platforms.

Development Notes

Usage

See this simple code example on how the Container Manager should be used in the process of creating a container.

ContainerManager Usage

package com.thales.chaos;

import com.thales.chaos.container.Container;
import com.thales.chaos.container.ContainerManager;
import com.thales.chaos.container.enums.ContainerHealth;
import com.thales.chaos.experiment.enums.ExperimentType;
import com.thales.chaos.notification.datadog.DataDogIdentifier;
import com.thales.chaos.platform.Platform;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.validation.constraints.NotNull;

@Service
public class Example {
    @Autowired
    private ContainerManager containerManager;

    private ExampleContainer getContainer (Object ... args) {
        ExampleContainer exampleContainer = containerManager.getMatchingContainer(ExampleContainer.class, args.getIdentifier());
        if (exampleContainer == null) {
            exampleContainer = actuallyCreateContainer();
            containerManager.offer(exampleContainer);
        }
        return exampleContainer;
    }

    private ExampleContainer actuallyCreateContainer()
    {
        return new ExampleContainer() {};
    }

    private abstract class ExampleContainer extends Container {
    }
}

In this example class, a Spring Service is attempting to look for an existing container if it already exists in the Container Manager cache (Line 20). If it does not exist (21), it will create the container using another call (22), and then offer that container back into the Container Manager (23), before finally returning the container (25) that was either retrieved from the cache or created.