Microservices can be built and tested using popular CI/CD tools, such as Jenkins and TeamCity. This is done very similarly to how a build is done in a monolithic application. In a microservices architecture, each microservice is treated like a small application.

For example, once you commit the code in the repository (SCM), CI/CD tools trigger the build process:

Cleaning code

Code compilation

Unit test execution

Contract/acceptance test execution

Building the application archives/container images

Publishing the archives/container images to repository management

Deployment on various delivery environments such as development, quality assurance, and staging environments

Integration and functional test execution

Any other steps

Then, release-build triggers, which change the SNAPSHOT or RELEASE version in pom.xml (in the case of Maven), build the artifacts as described in the normal build trigger, publish the artifacts to the artifacts repository, and tag the version in the repository. If you use the container image, then build the container image as a part of the build.

https://medium.com/@TracyRagan/understanding-microservice-pipelines-ca05b041d3c2