Expand Bamboo variables in Docker task

Summary
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Customers would like the ability to pass bamboo variables in to the Docker task.

This would allow the running of multiple instances of the same image on the same host, which can be extremely useful for testing. Having the ability to also pass in variables for the value of the container ports to be mapped or to set the name of the image to the branch it was built from would be beneficial.

Reproduction
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Using any variables produced by Bamboo in the Container or Port fields will not be correctly validated or expanded.

Workaround
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Workarounds at this time include using a script task to provide the variables to docker.

See also Pass In Variables