add docs/way of installing from external mirror

[Satish Patel]

Today i have started upgrading PIKE to QUEENS and my bootstrap took 5 hours to finish which is just checking out roles and found following.

Why don't we switch all URL in "ansible-role-requirements.yml" point to github.com ?

------------------ git.openstack.org ------Took 4 minute --------------

[root@ostack-osa /tmp]# time git clone https://git.openstack.org/openstack/openstack-ansible-rsyslog_client
Cloning into 'openstack-ansible-rsyslog_client'...
remote: Counting objects: 1224, done.
remote: Compressing objects: 100% (574/574), done.
remote: Total 1224 (delta 733), reused 1079 (delta 612)
Receiving objects: 100% (1224/1224), 266.25 KiB | 0 bytes/s, done.
Resolving deltas: 100% (733/733), done.

real 4m15.922s
user 0m0.203s
sys 0m0.118s

---------------- github.com ------------Took 1 second ------------------

[root@ostack-osa /tmp]# rm -rf openstack-ansible-rsyslog_client
[root@ostack-osa /tmp]#
[root@ostack-osa /tmp]# time git clone https://github.com/openstack/openstack-ansible-rsyslog_client
Cloning into 'openstack-ansible-rsyslog_client'...
remote: Counting objects: 1224, done.
remote: Compressing objects: 100% (19/19), done.
remote: Total 1224 (delta 7), reused 13 (delta 0), pack-reused 1204
Receiving objects: 100% (1224/1224), 270.43 KiB | 0 bytes/s, done.
Resolving deltas: 100% (747/747), done.

real 0m1.118s
user 0m0.169s
sys 0m0.105s

[Jesse Pretorius (jesse-pretorius)]

github's content is a mirror copy of git.openstack.org and is not guaranteed to be complete, but this can be done - I outlined an approach in a previous attempt to do this [1].

[1] https://review.openstack.org/434813

[Jean-Philippe Evrard (jean-philippe-evrard)]

The user can also override the ansible-role-requirements with its own a-r-r by exporting an env variable.

[Satish Patel (satish-txt)]

I understand we can do s/git.openstack.org/github.com/ but that me and you know underline code, new person has no idea and he will be endup like me sitting and waiting for 5 hour or more to just finish checkout, I can understand hour but its takes multiple hours sometime..

If we have some kind of check like `curl git.openstack.org` if slow do github.com

OR

Put that in documentation like if git.openstack.org is slow please use github

[Jesse Pretorius (jesse-pretorius)]

We should add documentation for how to do this better to make (near|off)line installs simpler and low bandwidth installs faster. Docs to link and update are:

https://docs.openstack.org/openstack-ansible/latest/reference/configuration/extending-osa.html#adding-new-or-overriding-roles-in-your-openstack-ansible-installation
https://docs.openstack.org/openstack-ansible/latest/user/limited-connectivity/index.html

[Jean-Philippe Evrard (jean-philippe-evrard)]

This way to do it is already in our reference documentation, but we can add links to it as part of a user story.

[Damian Dąbrowski (damiandabrowski)]

Recently, https://review.opendev.org/c/openstack/openstack-ansible/+/869748 was implemented so `sed` workaround is not needed anymore to switch to github mirrors.

I also believe that opendev.org is more reliable these days.