Use the mirror in China for Azure China environment

[lizzha]

We've set up a mirror of docker installation packages in Azure China, which syncs with docker repo every day, to mitigate the pain due to connection issues from China to docker official repo.
A new parameter is added in this change. If '-e AzureChinaCloud' is specified, the script will use the packages from the mirror in Azure China.

[thaJeztah]

Thank you for your contribution! I think this may need some extra eyes, as I don't know if there's objections against referring to a third-party mirror

ping @kencochrane @tianon @tibor

[lizzha]

@thaJeztah Thank you for the comment, we had some previous communication and agreement with Docker about this mirror.
@friism as FYI

[friism]

Thanks for the PR! Confirming that this was discussed previously and agree that there were no major objections raised. This should still go through the regular review process.

[thaJeztah]

LGTM

[tianon]

Overall, the idea sounds sane (and thanks to GPG, should be generally as safe as install.sh ever is), just some minor style comments. 👍

[tianon]

I think it'd make sense to move this whole block up closer to the initial setting of these variables (so we keep our constants all in one place, especially including the new args to the script this introduces).

[tianon]

$environment should be quoted here, and it might actually make sense to convert this to a case for simplicity, ie:

case "$environment" in
    AzureChinaCloud)
        ....
        ;;
esac

[tianon]

This variable ought to be initialized before this loop starts to ensure we don't get side effects from the enclosing shell, ie environment= on a line by itself right before the while starts.

[lizzha]

Thank you for reviewing. Comments addressed.

[thaJeztah]

I wonder if the option should have a more descriptive name (for example, -mirror?) @tianon wdyt?

[lizzha]

@thaJeztah can we use --mirror | -m ?

[tianon]

Yeah, "--mirror" sounds good to me! 👍

[lizzha]

Please let me know if you have more comments, thanks.

[thaJeztah]

@lizzha can you squash Your commits so that there's only a single commit in this PR?

[lizzha]

Done :)

[thaJeztah]

ping @tianon for final review / merge

[tianon]

LGTM

[lizzha]

Thank you! When will https://get.docker.com/ get refreshed with this change?

[thaJeztah]

@lizzha usually that script is updated with each release, and this just missed the 1.12.2 release; in exceptional cases we can update the script manually, but I'll have to ask if that applies here.

[twang2218]

I have 2 questions:

May I ask how to use this --mirror argument with https://get.docker.com if it's been updated? Is there any documentation about it?

Currently I use curl -sSL https://get.docker.com/ | sh to install the docker, I'm not quite sure how to add --mirror to it.

This PR is using the hardcoded Azure mirror, is there a way to use other mirror?

To avoid GFW issue, there are several mirrors in China provided by various cloud providers, such as:

• Aliyun:
  • http://mirrors.aliyun.com/docker-engine/apt/
  • http://mirrors.aliyun.com/docker-engine/yum/
• DaoCloud:
  • https://get.daocloud.io/docker/apt-repo
  • https://get.daocloud.io/docker/yum-repo

Is there a way to use those mirror? or Azure mirror is an official Docker mirror in China?

[lizzha]

@twang2218 once https://get.docker.com gets updated, you could use "curl -sSL https://get.docker.com/ | sh -s -- --mirror AzureChinaCloud" to install docker in China
The mirror is hosted in AzureChinaCloud and maintained by Microsoft. We have the agreement that the mirrored docker installation packages and script are exactly the same as the official ones.

[ushuz]

I recall there's a co-op between Docker Inc. and Alibaba Cloud to bring Docker Hub on Alibaba Cloud for China Mainland, how's that going?

[thaJeztah]

@ushuz this repo is for the open source "docker" project, I don't have additional information about that

[twang2218]

Created a PR #28858 to add Alibaba Cloud Docker apt/yum mirror support to 'hack/install.sh'