Docker history - multiple layers


If you run the same command on the mydocker image we have just created you can see that it has 2 more layers. Each RUN command created a layer.

Layers are created separately so having multiple layers makes our development process faster. However having many layers is not recommended so once in a while we usually merge the RUN instructions together and rebuild the image to have less layers. We'll talk about this later.


docker history mydocker


examples/dock/history_mydocker.out
IMAGE               CREATED             CREATED BY                                      SIZE
77dfbe63aa19        2 hours ago         /bin/sh -c apt-get install -y curl              16.2MB
05d6b032b3c6        2 hours ago         /bin/sh -c apt-get update                       22.3MB
74435f89ab78        4 weeks ago         /bin/sh -c #(nop)  CMD ["/bin/bash"]            0B
<missing>           4 weeks ago         /bin/sh -c mkdir -p /run/systemd && echo 'do…   7B
<missing>           4 weeks ago         /bin/sh -c set -xe   && echo '#!/bin/sh' > /…   811B
<missing>           4 weeks ago         /bin/sh -c [ -z "$(apt-get indextargets)" ]     1.01MB
<missing>           4 weeks ago         /bin/sh -c #(nop) ADD file:b2342c7e6665d5ff3…   72.8MB