Question: I am creating SQL Server database (not server) project for our existing database using VS2015 and SSDT (the latest version I think). I ran into a compile error saying :

> 
> Error SQL71501: User: [xxxxx] has an unresolved reference to Login
>  [xxxxxx].
> 
> 
> 

I came across [this](https://social.msdn.microsoft.com/Forums/en-US/1f8226fe-b791-4344-8735-3d38307e8664/error-1-sql03006-user-x-has-an-unresolved-reference-to-login-x?forum=vstsdb) post (the answer by Demetri M), that suggests to create a server project and have a current project reference that, but I do not see an option to create SQL Server SERVER (not Database) project in VS2015.

[This](https://msdn.microsoft.com/en-us/library/84b1se47(v=vs.90).aspx) documentation from MSDN didn't help either.Is this something that is no longer valid?

Answer: 
Most answers give us OS release, but the question is also concern docker.

I'm lazy, especially when I have more than 20 images, so:

`docker image ls | perl -lane 'print "docker run --rm $F[0]:$F[1] cat /etc/os-release" unless /REPOSITORY/' | sh | grep PRETTY`

And most images have results:

```
> PRETTY_NAME="Ubuntu 16.04.1 LTS"
> PRETTY_NAME="Ubuntu 14.04.3 LTS"
> PRETTY_NAME="Ubuntu 18.04.1 LTS"
> PRETTY_NAME="Debian GNU/Linux 9 (stretch)" 
> PRETTY_NAME="Debian GNU/Linux 9 (stretch)"
> PRETTY_NAME="Debian GNU/Linux bullseye/sid"
> PRETTY_NAME="Ubuntu 18.04.3 LTS"
> PRETTY_NAME="Ubuntu 16.04.1 LTS"
> ...

```
If you don't want to do any action on the image you mat try to figure out winch os it base on the firsts layers .

for finding the layers just type

```
docker inspect <image name>

```

then see the layer section.
then you can make a list of each layer belong to which base image