DevOps is the combination of development, testing & operations and it also includes continuous integration, automated testing, continuous delivery & rapid deployment practices. Because DevOps practices requires confidence that the modifications are made to the code base will functions as expected, automated testing is an essential ingredient that it is integrated in the process of every step & relied upon for enforcement of quality gates & to ensure the overall delivery quality.
Integration testing is a part of the software testing in which the specific software modules are combined & tested as a group. It occurs after unit testing & before validation testing. It takes the input modules that have been unit tested and groups them into larger aggregates, applies tests that defined in an integration test plan to those aggregates & delivers its output. the integrated system is ready for system testing.
The purpose of the integration testing is to verify functional, reliability & performance requirements placed on major design items. These design items, such as, assemblages or groups of units are exercised through their interfaces by using black box testing, success & error cases being simulated via appropriate parameter & data inputs. Simulated usage of shared data areas & inter-process communication is tested & the individual sub-systems are exercised through their input interface. The Test cases are build to be test whether all the components within assemblages interact correctly.