As time goes by while we build our Docker container, its size will get bigger and bigger. Updating running containers in our existing Docker hosts is not a problem. Docker takes advantage of the Docker image layers that we build over time as our application grows; however, consider the case where we want to scale out our application. This requires deploying more Docker containers to additional Docker hosts. In this case, each new Docker host will have to download all of the large image layers that we built over time. This section will show you how a large Docker application affects deployment time on new Docker hosts. First, let's build this problematic Docker application by carrying out the following steps:
- Write the following Dockerfile to create our large Docker image:
FROM debian:stretch RUN dd if=/dev/urandom of=/largefile bs=1024 count=524288
- Next, build the Dockerfile as
hubuser/largeappusing the following command:
dockerhost$ docker build -t hubuser/largeapp...