Move the VOLUME declaration to the end of the Dockerfile #126
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One a VOLUME has been declared, changes to that location are subsequently dropped during the building of the Dockerfile. With the changes, in rabbitmq/rabbitmq-common#369 applied, this meant that the enabling of plugins no longer worked. We now make the VOLUME declaration the last line of the Dockerfile, assuming that we would not want to throw out any changes. Additionally, we use gosu to execute plugin enablement, so that the 'enabled_plugins' file is owned by the rabbitmq user when the broker goes to update it.
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I have only just noticed this. It's a good change! Since this Dockerfile is tracking https://github.com/docker-library/rabbitmq, do you want to contribute this PR there instead? |
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@gerhard They declare the VOLUME at the end of the base Dockerfile, then the management image inherits from that, so it's kind of already at the end. Still, I think I will raise an issue to see if there is a way of addressing it that I haven't thought of. |
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@gerhard I've created docker-library/rabbitmq#410, but it's not clear to me what a good solution would be. Drop the volume declaration entirely? Unfortunately the ignore changes effect cascades to inheriting Dockerfiles, so this is not an artifact of this repo flattening two Dockerfiles into 1. |
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Based on docker-library/rabbitmq#410 (comment), I think it's unlikely the declaration is removed upstream. I think this supports @dumbbell 's point in rabbitmq/rabbitmq-server#2234, that the file being both current state and configuration is not ideal and has drawbacks. I would say that the list of enabled plugins on startup should be taken from the .conf/.config file, and that runtime changes of enabled plugins could be reflected in this file in the data dir, but that presents a bit of a problem with the |
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@gerhard I think I've ultimately decided that I would recommend dropping this change: rabbitmq/rabbitmq-server#2234 (comment) |
One a VOLUME has been declared, changes to that location are subsequently dropped during the building of the Dockerfile. With the changes in rabbitmq/rabbitmq-common#369 applied, this meant that the enabling of plugins no longer worked correctly. We now make the VOLUME declaration the last line of the Dockerfile, assuming that we would not want to throw out any changes.
Additionally, we use gosu to execute plugin enablement, so that the 'enabled_plugins' file is owned by the rabbitmq user when the broker goes to update it.