Re:Varlink: Interface description format and protocol for hu...
by jitl on Sunday January 03, 2021 @10:12AM
(#25622177)
Here are some facts I gathered last time Varlink was discussed:
Varlink is produced by Red Hat, apparently - or by people who use Red Hat things: both examples (DNF, Podman) are Redhat projects.
It seems to be an effort to apply the Interface Definition Language model to UNIX daemons/services/tools by adding a new “standard IO file descriptor” for structured IO using a typed interface, as opposed to the current STDIN/STDOUT/STDERR which are existing un typed byte streams.
Using a new FD instead of agreeing to layer Varlink protocol over STDIO means that existing programs can adopt Varlink without breaking backwards compat or making negotiation even more complicated.
Varlink is produced by Red Hat, apparently - or by people who use Red Hat things: both examples (DNF, Podman) are Redhat projects.
It seems to be an effort to apply the Interface Definition Language model to UNIX daemons/services/tools by adding a new “standard IO file descriptor” for structured IO using a typed interface, as opposed to the current STDIN/STDOUT/STDERR which are existing un typed byte streams.
Using a new FD instead of agreeing to layer Varlink protocol over STDIO means that existing programs can adopt Varlink without breaking backwards compat or making negotiation even more complicated.
EDIT: Podman removed Varlink https://podman.io/blogs/2020/01/17/podman-new-api.html