[ubuntu] use /etc/os-release instead of lsb_release

[chriscn]

The /etc/os-release file is the standard. Any distribution based on systemd, including Red Hat Enterprise Linux, CentOS, Fedora, Gentoo, Debian, Mint, Ubuntu, and many others, is required to have that file. Distributions that don't use systemd may also have the file.

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[captn3m0]

But this is the Ubuntu specific page, so others are irrelevant. I remember picking lsb_release because it gave a clearer answer to the question of "what release am I at".

But I noticed today, that it's not installed on Ubuntu minimal containers, so it's not perfect either.

I want to double check on this, give me a bit.

[usta]

The /etc/os-release file is the standard. Any distribution based on systemd, including Red Hat Enterprise Linux, CentOS, Fedora, Gentoo, Debian, Mint, Ubuntu, and many others, is required to have that file. Distributions that don't use systemd may also have the file.

lsb_release is a common tool for almost all linux distro and ubuntu is also have it default. It doesnt just gives release version but also other info ( if you use with -a ) . And as far as i know it first checks /etc/lsb-release and if it doesnt exist it takes values from /etc/os-release . So this what this commit/PR brings for us ? [ the related tool already exist in *ubuntu distros except minimal containers ]

[chriscn]

https://lwn.net/Articles/658809/ - linux standard base has been deprecated from 2015 and removed. They've kept this command around but for posterity. The recommended way is to use /etc/os-release.