How to use Circle CI?

CicleCI is CI service.
https://circleci.com/

By registering from the above page, we can automatically build, test, and deploy like Jenkins.

Jenkins needs to set up a Jenkins server on its own, but since CircleCI is a service that can be used only by registering.

Features
– It is a CI service
– Can cooperate with GitHub
– Run the build in the container under the concept of container
– Free for one container use (billing is required for multiple use)

Concept of Container
Although it is not limited to CircleCI, the CI tool has the concept of “Container”

Features
– As the name implies “box/container” image
– Run build, test and deploy in the container
– As the number of containers increases, the speed increases as it can be executed in parallel. However, CircleCI will be charged for using more than two containers.

When executing two or more builds, waiting time occurs because only one can be executed even when we run a lot of test, it can take time only because it can only be executed in series.