• Brad Fitzpatrick's avatar
    net: add mechanisms to force go or cgo lookup, and to debug default strategy · b615ad8f
    Brad Fitzpatrick authored
    GODEBUG=netdns=1 prints a one-time strategy decision. (cgo or go DNS lookups)
    GODEBUG=netdns=2 prints the per-lookup strategy as a function of the hostname.
    
    The new "netcgo" build tag forces cgo DNS lookups.
    
    GODEBUG=netdns=go (or existing build tag "netgo") forces Go DNS resolution.
    GODEBUG=netdns=cgo (or new build tag "netcgo") forces libc DNS resolution.
    
    Options can be combined with e.g. GODEBUG=netdns=go+1 or GODEBUG=netdns=2+cgo.
    
    Fixes #11322
    Fixes #11450
    
    Change-Id: I7a67e9f759fd0a02320e7803f9ded1638b19e861
    Reviewed-on: https://go-review.googlesource.com/11584Reviewed-by: 's avatarRuss Cox <rsc@golang.org>
    Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
    b615ad8f
net.go 15.1 KB