public boolean isContainer() {
        if (properties.containsKey(CONTAINER_PROPERTY_KEY)) {
            return readPropertyBool(CONTAINER_PROPERTY_KEY);
        } else {
            return isDockerEnv();
        }
    }
Returns <tt>true</tt> if {@value #CONTAINER_PROPERTY_KEY} property exists and has no value or is <tt>true</tt>.

@return <tt>true</tt> if {@value #CONTAINER_PROPERTY_KEY} property exists and has no value or is <tt>true</tt>.
agent-module/profiler/src/main/java/com/navercorp/pinpoint/profiler/util/ContainerResolver.java