Use VERSION_ID instead of VERSION field for platform version

[ISauve]

VERSION can include release code name, whereas VERSION_ID is a simplified identifier containing no spaces (i.e. VERSION="17 (Beefy Miracle)", VERSION_ID=17). This makes it much more useful for programmatic usage (specifically, for using version as part of a file path).

If we want the codename in the future, we could always get that from VERSION_CODENAME and return that separately.

Edit: This only affects platform information read from the /etc/os-release file. When platform data is read from /etc/lsb-release (the default location), we get the version information from the DISTRIB_RELEASE field, which is already in this simplified format.

[paulcacheux]

Won't this change impact all other customers of the host.Info() ? This look like a pretty big change

[paulcacheux]

For example with this change https://github.com/DataDog/datadog-agent/blob/48bb5106f06cba0df9283acca961cb346bab0e88/pkg/process/checks/system_info.go#L52 does not return the same value no ?

[ISauve]

You're right that the process-agent reads this data (we don't need to worry about other places in the agent as it uses the main fork), but I couldn't find any specific place where it uses the Version field in a way which would be affected by this change. We can check with someone from the processes team to be certain though!

FWIW, this isn't a major change as it just makes os-release return the same information as reading from lsb-release already gives us (and reading from lsb-release is the default behaviour). So all consumers of this data should already expect to receive data in this format.

[ISauve]

@mbotarro has taken a look and confirmed that this should be a safe change

[brycekahle]

shirou#1585