TheArchive/tailscale
1
0
Fork 0
mirror of https://github.com/tailscale/tailscale.git synced 2024-11-29 04:55:31 +00:00
Code Issues Packages Projects Releases Wiki Activity

ipn/ipnlocal: bound how long cert fetchher checks for existing DNS records

Browse Source 
It was supposed to be best effort but in some cases (macsys at least,
per @marwan-at-work) it hangs and exhausts the whole context.Context
deadline so we fail to make the SetDNS call to the server.

Updates #8067
Updates #3273 etc

Change-Id: Ie1f04abe9689951484748aecdeae312afbafdb0f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2023-05-05 12:19:25 -07:00 committed by Brad Fitzpatrick
parent 9ed3a061c3
commit 8864112a0c
1 changed files with 10 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
ipn/ipnlocal/cert.go
View File

@ -31,6 +31,7 @@
"time"
"golang.org/x/crypto/acme"
"golang.org/x/exp/slices"
"tailscale.com/atomicfile"
"tailscale.com/envknob"
"tailscale.com/hostinfo"
@ -361,17 +362,16 @@ func (b *LocalBackend) getCertPEM(ctx context.Context, cs certStore, logf logger
}
key := "_acme-challenge." + domain
// Do a best-effort lookup to see if we've already created this DNS name
// in a previous attempt. Don't burn too much time on it, though. Worst
// case we ask the server to create something that already exists.
var resolver net.Resolver
var ok bool
txts, _ := resolver.LookupTXT(ctx, key)
for _, txt := range txts {
if txt == rec {
ok = true
logf("TXT record already existed")
break
}
}
if !ok {
lookupCtx, lookupCancel := context.WithTimeout(ctx, 500*time.Millisecond)
txts, _ := resolver.LookupTXT(lookupCtx, key)
lookupCancel()
if slices.Contains(txts, rec) {
logf("TXT record already existed")
} else {
logf("starting SetDNS call...")
err = b.SetDNS(ctx, key, rec)
if err != nil {