After a little bit more digging, I think the cygwin name is coming from the output of getent here:

https://cygwin.com/git/gitweb.cgi?p=cygwin-csih.git;a=blob;f=cygwin-service-installation-helper.sh;h=10ab4fb6d47803c9ffabdde51923fc2c3f0496bb;hb=7ca191bebb52ae414bb2a2e37ef22d94f2658dc7#l2705

At this point, I’m not sure what causes getent to return different values when run in automation, and when run manually. I wonder if there is some kind of race condition, such that some subsystem is still updating at the point I install cygwin sshd.

For reference, this is the powershell script, see lines 77 onwards:
https://hg.mozilla.org/try/file/4905af7c52e5/testing/taskcluster/worker_types/win2012r2/aws_userdata

Thanks!
Pete



> On 03 Oct 2015, at 19:12, Peter Moore <pmoore@mozilla.com> wrote:
> 
> Hi,
> 
> I have a powershell script for installing cygwin and setting up sshd which I am using as UserData when firing up a Windows 2012 R2 instance in AWS EC2.
> 
> The same command succeeds when run manually, but fails when called from automation. I’m trying to understand what it is that is different, so I can fix it in automation.
> 
> The command called is:
> 
> ssh-host-config -y -c 'ntsec mintty' -u 'cygwinsshd' -w 'qwe123QWE!@#'
> 
> When I run manually, logged in as Administrator, I get a log line like this (notice the correct “Cygwin name”):
> 
> *** Query: Create new privileged user account 'WIN-EFPDIM0SAUP\cygwinsshd' (Cygwin name: ‘cygwinsshd')? (yes/no) yes
> 
> When I run from automation, the log line looks like this (notice the incorrect “Cygwin name”):
> 
> *** Query: Create new privileged user account 'WIN-EFPDIM0SAUP\cygwinsshd' (Cygwin name: 'win-efpdim0saup+cygwinsshd')? (yes/no) yes
> 
> It seems the extended “Cygwin name” which I get in automation causes ssh-host-config to fail. I’m trying to establish what causes the cygwin name to get the prefix of the machine name, since this seems to cause the problem.
> 
> For reference, below I’ve put the logs in both the successful (manual) case, and the failing (automated) case.
> 
> If anyone can point me to the source code of ssh-host-config I’m also happy to dig - I couldn’t find it online. So if you’re not sure, but know where the source is, I’m happy to look.
> 
> Many thanks in advance!
> Pete
> 
> 
> 
> SUCCESSFUL run (when executed manually):
> 
> *** Query: Create new privileged user account 'WIN-EFPDIM0SAUP\cygwinsshd' (Cygwin name: ‘cygwinsshd')? (yes/no) yes
> *** Info: User ‘cygwinsshd' has been created with password 'qwe123QWE!@#'.
> *** Info: If you change the password, please remember also to change the
> *** Info: password for the installed services which use (or will soon use)
> *** Info: the ‘cygwinsshd' account.
> 
> *** Info: The sshd service has been installed under the ‘cygwinsshd'
> *** Info: account.  To start the service now, call `net start sshd' or
> *** Info: `cygrunsrv -S sshd'.  Otherwise, it will start automatically
> *** Info: after the next reboot.
> *** Info: Host configuration finished. Have fun!
> 
> 
> FAILED run (when called in automation):
> 
> *** Query: Create new privileged user account 'WIN-EFPDIM0SAUP\cygwinsshd' (Cygwin name: 'win-efpdim0saup+cygwinsshd')? (yes/no) yes
> *** Info: User 'win-efpdim0saup+cygwinsshd' has been created with password 'qwe123QWE!@#'.
> *** Info: If you change the password, please remember also to change the
> *** Info: password for the installed services which use (or will soon use)
> *** Info: the 'win-efpdim0saup+cygwinsshd' account.
> 
> *** Warning: Setting password expiry for user 'win-efpdim0saup+cygwinsshd' failed!
> *** Warning: Please check that password never expires or set it to your needs.
> No user or group 'win-efpdim0saup+cygwinsshd' known.
> *** Warning: Assigning the appropriate privileges to user 'win-efpdim0saup+cygwinsshd' failed!
> *** ERROR: There was a serious problem creating a privileged user.
>