This is a nice hack to workaround a bug in docker-plugin

hack-docker-plugin-instance-cap.groovy

def c = com.nirima.jenkins.plugins.docker.DockerCloud.getCloudByName('Host docker')

// We're going to hack java final fields here...
import java.lang.reflect.Field
import java.lang.reflect.Modifier

for (def jt in c.getJobTemplates().values()) {
	Field field = jt.getClass().getDeclaredField("instanceCap")

	Field modifiersField = Field.class.getDeclaredField("modifiers")
	modifiersField.setAccessible(true)
	modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL)

	field.setAccessible(true)
	field.set(jt, Integer.MAX_VALUE)

	println jt
}