From f91c55d6cdf81f56707d0ee6b47f50d164555d68 Mon Sep 17 00:00:00 2001 From: Gonzalo Paniagua Javier Date: Sun, 17 Nov 2019 23:58:00 -0800 Subject: [PATCH] Fix reloading in plugin/pprof. (#3454) * Fix reloading in plugin/pprof. Reloading the server without changing the listen address results in an error because Startup is called for newly set up plugins before Shutdown is called for the old ones. Signed-off-by: Gonzalo Paniagua Javier * Use pkg/reuseport when listening. Use coredns' newly added reuseport. Signed-off-by: Gonzalo Paniagua Javier * Revert go.{mod,sum} changes. Signed-off-by: Gonzalo Paniagua Javier --- plugin/pprof/pprof.go | 7 ++++++- plugin/pprof/setup.go | 10 ++-------- 2 files changed, 8 insertions(+), 9 deletions(-) diff --git a/plugin/pprof/pprof.go b/plugin/pprof/pprof.go index c53010089..ddf5ab2df 100644 --- a/plugin/pprof/pprof.go +++ b/plugin/pprof/pprof.go @@ -7,6 +7,8 @@ import ( "net/http" pp "net/http/pprof" "runtime" + + "github.com/coredns/coredns/plugin/pkg/reuseport" ) type handler struct { @@ -17,7 +19,10 @@ type handler struct { } func (h *handler) Startup() error { - ln, err := net.Listen("tcp", h.addr) + // Reloading the plugin without changing the listening address results + // in an error unless we reuse the port because Startup is called for + // new handlers before Shutdown is called for the old ones. + ln, err := reuseport.Listen("tcp", h.addr) if err != nil { log.Errorf("Failed to start pprof handler: %s", err) return err diff --git a/plugin/pprof/setup.go b/plugin/pprof/setup.go index 8de3b2ac0..a9b93673c 100644 --- a/plugin/pprof/setup.go +++ b/plugin/pprof/setup.go @@ -3,7 +3,6 @@ package pprof import ( "net" "strconv" - "sync" "github.com/coredns/coredns/plugin" clog "github.com/coredns/coredns/plugin/pkg/log" @@ -62,12 +61,7 @@ func setup(c *caddy.Controller) error { } - pprofOnce.Do(func() { - c.OnStartup(h.Startup) - c.OnShutdown(h.Shutdown) - }) - + c.OnStartup(h.Startup) + c.OnShutdown(h.Shutdown) return nil } - -var pprofOnce sync.Once