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 --max-concurrent-downloads like so:
docker run --rm -p 8787:8787 -e PASSWORD=blah --max-concurrent-downloads=1 rocker/verse
But this gives an error:
unknown flag: --max-concurrent-downloads See 'docker run --help'.
I tried typing docker run --help and interestingly did not see the option --max-concurrent-downloads.
I'm using Docker Toolbox since I'm on a old Mac.
Over here under l there's an option for --max-concurrent-downloads however this doesn't appear on my terminal when typing docker run --help
How can I change the default of downloading 3 layers at a time to just one?
From the official documentation: (https://docs.docker.com/engine/reference/commandline/pull/#concurrent-downloads)
You can pass --max-concurrent-downloads during a pull operation.
You can set --max-concurrent-downloads with the dockerd command.
If you're using the docker Desktop GUI for Mac or Windows:
You can edit the .json file directly in docker engine settings:
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:
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 defaultOpen Docker profile
$ sudo vi /var/lib/boot2docker/profile
Then in that profile, you would add your --engine-opt max-concurrent-downloads=1.
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
}