a PostgreSQLContainer for use in TestContainer-integrated builds that allows simulating a restart of the database.

RestartablePostgreSQLContainer.java

import com.github.dockerjava.api.command.CreateContainerCmd;
import com.github.dockerjava.api.model.RestartPolicy;
import org.springframework.util.SocketUtils;
import org.testcontainers.containers.PostgreSQLContainer;
import org.testcontainers.containers.output.OutputFrame;
import org.testcontainers.utility.DockerImageName;

import java.io.IOException;
import java.util.Objects;

/**
 * A variant of {@link PostgreSQLContainer} that exposes the ability to restart the instance.
 */
public class RestartablePostgreSQLContainer<SELF extends RestartablePostgreSQLContainer<SELF>> extends PostgreSQLContainer<SELF> {

    public RestartablePostgreSQLContainer(DockerImageName dockerImageName) {
        super(dockerImageName);

        withCreateContainerCmdModifier(RestartablePostgreSQLContainer::alwaysRestartContainer);
        addFixedExposedPort(SocketUtils.findAvailableTcpPort(), 5432);
        withLogConsumer(of -> {
            // When the container terminates, this is needed to re-follow it's output
            if(of.getType() == OutputFrame.OutputType.END) {
                getLogConsumers().forEach(this::followOutput);
            }
        });
    }

    private static void alwaysRestartContainer(CreateContainerCmd c) {
        c.withHostConfig(Objects.requireNonNull(c.getHostConfig()).withRestartPolicy(RestartPolicy.alwaysRestart()));
    }

    public void restart() {
        try {
            var result = execInContainer("su", "postgres", "-c", "pg_ctl restart");
            logger().debug("restarted database. {}", result);
            if (result.getExitCode() != 137) {
                throw new RuntimeException("Failed to restart database: " + result);
            }
        } catch (IOException | InterruptedException e) {
            throw new RuntimeException("Failed to restart database", e);
        }
    }
}