Can I pass --max-concurrent-downloads as a flag?

Question

I\'m working with a poor internet connection and trying to pull and run a image.

I wanted to download one layer at a time and per documentation tried adding a flat -

Answer 1

If you're using docker for mac:

Just add the same settings in the json directly in docker engine settings:

Answer 2

This setting needs to be passed to dockerd when starting the daemon, not to the docker client CLI. The dockerd process is running inside of a VM with docker-machine (and other docker desktop environments).

With docker-machine that is used in toolbox, you typically pass the engine flags on the docker-machine create command line, e.g.

docker-machine create --engine-opt max-concurrent-downloads=1

Once you have a created machine, you can follow the steps from these answers to modify the config of an already running machine, mainly:

1. SSH into your local docker VM.
   note: if 'default' is not the name of your docker machine then substitute 'default' with your docker machine name $ docker-machine ssh default

2. Open Docker profile $ sudo vi /var/lib/boot2docker/profile

Then in that profile, you would add your --engine-opt max-concurrent-downloads=1.

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Newer versions of docker desktop (along with any Linux install) make this much easier with a configuration menu daemon -> advanced where you can specify your daemon.json entries like:

{
  "max-concurrent-downloads": 1
}