Get minor version of debian-slim

问题

I am setting up my container creation pipeline and I need to be able to get the major AND minor version of the debian-slim build my container is built on.

I tried the following command:

docker run -it --rm -a stdout --entrypoint lsb_release MyContainer:1.0.0 -a

but that just returns:

Distributor ID: Debian  
Description:    Debian GNU/Linux 10 (buster)   
Release:        10  
Codename:       buster

No minor version listed.

I have also tried:

docker run -it --rm -a stdout --entrypoint cat MyContainer:1.0.0 "/etc/os-release"

but that only outputs:

PRETTY_NAME="Debian GNU/Linux 10 (buster)"
NAME="Debian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"

again, no minor version.

Is there a way to get the minor version? Does the container OS even know its full version number?

回答1:

In fact, in the old days on Debian9, you could use lsb_release -a to get the minor version as next:

$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 9.5 (stretch)
Release:        9.5
Codename:       stretch

You may know, /usr/bin/lsb_release will finally call /usr/lib/python3/dist-packages/lsb_release.py, the realization diff for this script between debian9 & debian10 made the difference.

In debian9, it's next:

def get_distro_information():
    lsbinfo = get_lsb_information()
    # OS is only used inside guess_debian_release anyway
    for key in ('ID', 'RELEASE', 'CODENAME', 'DESCRIPTION',):
        if key not in lsbinfo:
            distinfo = guess_debian_release()
            distinfo.update(lsbinfo)
            return distinfo
    else:
        return lsbinfo

get_lsb_release will fetch the contents of /etc/lsb-release, but there is no file in debian release, so it returns none. Then the procedure have to fallback to guess_debian_release which will fetch the contents from /etc/debian_version, so you get the minor version.

In debian10, it's next:

def get_distro_information():
    lsbinfo = get_os_release()
    # OS is only used inside guess_debian_release anyway
    for key in ('ID', 'RELEASE', 'CODENAME', 'DESCRIPTION',):
        if key not in lsbinfo:
            distinfo = guess_debian_release()
            distinfo.update(lsbinfo)
            return distinfo
        else:
            return lsbinfo

get_os_release will fetch the contents of /usr/lib/os-release, the contens is next:

PRETTY_NAME="Debian GNU/Linux 10 (buster)"
NAME="Debian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"

As it already get the version, so nolonger fallback to guess_debian_release, so you did not get the minor version. The advantage I guess is if not use guess_debian_release, it will use less IO operation, but in my opinion, really countless (Also maybe some hardcoding for guess).

Finally, as a workaround, on debian10, you could use next to get the same behavior as debian 9:

$ LSB_OS_RELEASE="" lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 10.4 (buster)
Release:        10.4
Codename:       buster

回答2:

Should have looked a bit harder. (Found it right after posting)

Debian does it their own way by putting it in the custom, nonstandard, Debian specific file /etc/debian_version found only on Debian Linux:

docker run -it --rm -a stdout --entrypoint cat MyContainer:1.0.0 "/etc/debian_version"

<rant>Why do they not follow the standard of using lsb_release?</rant>

来源：https://stackoverflow.com/questions/65117854/get-minor-version-of-debian-slim

标签

Linux

Docker

debian

containers