From d18747e846f9b2c4c72077c95cafd0cba296311e Mon Sep 17 00:00:00 2001 From: Zoltan Papp Date: Tue, 24 Feb 2026 16:48:38 +0100 Subject: [PATCH] [client] Exclude Flow domain from caching to prevent TLS failures (#5433) * Exclude Flow domain from caching to prevent TLS failures due to stale records. * Fix test --- client/internal/dns/mgmt/mgmt.go | 6 +++--- client/internal/dns/mgmt/mgmt_test.go | 9 +++++---- 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/client/internal/dns/mgmt/mgmt.go b/client/internal/dns/mgmt/mgmt.go index d01be0c2c..314af51d9 100644 --- a/client/internal/dns/mgmt/mgmt.go +++ b/client/internal/dns/mgmt/mgmt.go @@ -376,9 +376,9 @@ func (m *Resolver) extractDomainsFromServerDomains(serverDomains dnsconfig.Serve } } - if serverDomains.Flow != "" { - domains = append(domains, serverDomains.Flow) - } + // Flow receiver domain is intentionally excluded from caching. + // Cloud providers may rotate the IP behind this domain; a stale cached record + // causes TLS certificate verification failures on reconnect. for _, stun := range serverDomains.Stuns { if stun != "" { diff --git a/client/internal/dns/mgmt/mgmt_test.go b/client/internal/dns/mgmt/mgmt_test.go index 99d289871..9e8a746f3 100644 --- a/client/internal/dns/mgmt/mgmt_test.go +++ b/client/internal/dns/mgmt/mgmt_test.go @@ -391,7 +391,8 @@ func TestResolver_PartialUpdateAddsNewTypePreservesExisting(t *testing.T) { } assert.Len(t, resolver.GetCachedDomains(), 3) - // Update with partial ServerDomains (only flow domain - new type, should preserve all existing) + // Update with partial ServerDomains (only flow domain - flow is intentionally excluded from + // caching to prevent TLS failures from stale records, so all existing domains are preserved) partialDomains := dnsconfig.ServerDomains{ Flow: "github.com", } @@ -400,10 +401,10 @@ func TestResolver_PartialUpdateAddsNewTypePreservesExisting(t *testing.T) { t.Skipf("Skipping test due to DNS resolution failure: %v", err) } - assert.Len(t, removedDomains, 0, "Should not remove any domains when adding new type") + assert.Len(t, removedDomains, 0, "Should not remove any domains when only flow domain is provided") finalDomains := resolver.GetCachedDomains() - assert.Len(t, finalDomains, 4, "Should have all original domains plus new flow domain") + assert.Len(t, finalDomains, 3, "Flow domain is not cached; all original domains should be preserved") domainStrings := make([]string, len(finalDomains)) for i, d := range finalDomains { @@ -412,5 +413,5 @@ func TestResolver_PartialUpdateAddsNewTypePreservesExisting(t *testing.T) { assert.Contains(t, domainStrings, "example.org") assert.Contains(t, domainStrings, "google.com") assert.Contains(t, domainStrings, "cloudflare.com") - assert.Contains(t, domainStrings, "github.com") + assert.NotContains(t, domainStrings, "github.com") }