Nowadays Microservice, as one of the most important architectural approaches towards Cloud Computing, has caught the attention of many developers. To give a simple definition of microservice, it could be said: Each microservice is completely independent, and implements a part of the business, which is composed of several microservices. Each microservice could be deployed, updated, and scaled, without any impact on other microservices, and it is all automated. Among Agile methods, Continuous Delivery has played an important role in development process of Microservice-based systems. Continuous Delivery provides faster delivery of changes and faster getting customer's feedbacks. Continuous Delivery consists of many sections, one of which is Software Test. One of the challenges of automated deploying of new releases to production environment, is software reliability, that in case it is breached, the beneficiaries would suffer considerable losses. Regression test is one of the tests used for ensuring reliability, which compares two system versions based on various metrics. This paper proposes an automated method in running this test, which places Regression test in Continuous Delivery steps, which tests operability of the last developed version as a black box, and prevents writing test unit. Finally, microservice developers could ensure the operability of the developed microservice dependencies through investigating obtained comparisons.

• microservice,
• regression test,
• continuous delivery,
• DevOps