CODEWITHSUNDEEP
dockerdocker-image
rgamber
rgamber

Reputation: 5849

Updating a container created from a custom dockerfile

Before anything, I have read this question and the related links in it, but I am still confused about how to resolve this on my setup.

I wrote my own docker file to install Archiva, which is very similar to this file. I created an image from the docker file using docker build -t archiva . and have a container which I run using docker run archiva. As seen in the docker file, the user data that I want to preserve is in a volume.

Now I want to upgrade to Archive 2.2.0. How can I update my container, so that the user-data thats in the volume is preserved? If I change the docker file by h=just changing the version number, and run the docker build again, it will just create another container.

Upvotes: 0

Views: 117

Answers (1)

Auzias
Auzias

Reputation: 3798

Best practice

The option --volume of the docker-run enables sharing files between host and container(s) and especially preserve consistent [user] data.

The problem is ..

.. it appears that you are not using --volume and that the user data are in the image. (and that's a bad practice beacuse it leads to the situation you are in: unable to upgrade a service easily.

One solution (the best IMO) is

Back-up the user data

To use the command docker-cp: "Copy files/folders between a container and the local filesystem."

docker cp [--help] CONTAINER:SRC_PATH DEST_PATH

Upgrade your Dockerfile

By editing your Dockerfile and changing the version.

Use the --volume option

Use docker run -v /host/path/user-data:container/path/user-data archiva

And you're good!

Upvotes: 1

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