Files
dnswatcher/internal/server/server_test.go
sneak 02b63a4e65
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server: set ReadTimeout, WriteTimeout, and IdleTimeout (closes #99)
The http.Server literal only set ReadHeaderTimeout. The other three
timeouts defaulted to zero, which in net/http means no limit: past the
header phase a peer could hold a connection open forever, responses had
no write deadline, and keep-alive connections were never reaped.
REPO_POLICIES.md requires all four before 1.0.

All four are now named constants in internal/server/server.go:

  ReadHeaderTimeout  10s  (unchanged)
  ReadTimeout        15s  whole request; every route is a bodyless GET
  WriteTimeout       75s  handler execution plus response flush
  IdleTimeout       120s  keep-alive reaping

WriteTimeout must exceed the 60s chimw.Timeout handler budget in
routes.go. net/http arms the write deadline once the request headers
have been read, so it covers handler execution as well as the response
write; a smaller value would sever the connection before a handler that
legitimately used its full budget could respond, making that budget
unreachable. The 15s difference is the response-flush allowance. The
comment on the const block states this relationship.

IdleTimeout sits above the common Prometheus scrape intervals so the
scraper reuses its connection instead of reconnecting each cycle, while
an abandoned connection is still reaped within two minutes.

The http.Server literal moved into newHTTPServer so the configuration
is testable without binding a socket. Tests assert all four fields are
non-zero, that WriteTimeout exceeds the handler budget, and that
ReadTimeout covers ReadHeaderTimeout; they compare configured values
only and measure no elapsed time, so they cannot flake.
2026-08-09 05:40:31 +00:00

113 lines
2.9 KiB
Go

package server_test
import (
"net/http"
"testing"
"sneak.berlin/go/dnswatcher/internal/server"
)
// noopHandler stands in for the router; newHTTPServer only stores it.
func noopHandler() http.Handler {
return http.HandlerFunc(
func(w http.ResponseWriter, _ *http.Request) {
w.WriteHeader(http.StatusOK)
},
)
}
// TestHTTPServerTimeoutsAreSet asserts that every socket-level
// timeout is configured. A zero value in net/http means "no limit",
// so a refactor that silently drops one of these reintroduces the
// slowloris / unreaped-keep-alive exposure this guards against.
//
// The assertions are on the configured field values only; nothing
// here measures elapsed time, so the test cannot flake on timing.
func TestHTTPServerTimeoutsAreSet(t *testing.T) {
t.Parallel()
srv := server.NewHTTPServer(":8080", noopHandler())
if srv.ReadTimeout <= 0 {
t.Errorf(
"ReadTimeout must be non-zero, got %v",
srv.ReadTimeout,
)
}
if srv.ReadHeaderTimeout <= 0 {
t.Errorf(
"ReadHeaderTimeout must be non-zero, got %v",
srv.ReadHeaderTimeout,
)
}
if srv.WriteTimeout <= 0 {
t.Errorf(
"WriteTimeout must be non-zero, got %v",
srv.WriteTimeout,
)
}
if srv.IdleTimeout <= 0 {
t.Errorf(
"IdleTimeout must be non-zero, got %v",
srv.IdleTimeout,
)
}
}
// TestWriteTimeoutExceedsHandlerBudget pins the one relationship the
// values must satisfy. net/http arms the write deadline once request
// headers are read, so it covers handler execution plus the response
// flush. If WriteTimeout were not greater than the chimw.Timeout
// handler budget, the connection would be severed before a handler
// that used its full budget could respond, making that budget
// unreachable.
func TestWriteTimeoutExceedsHandlerBudget(t *testing.T) {
t.Parallel()
srv := server.NewHTTPServer(":8080", noopHandler())
if srv.WriteTimeout <= server.RequestTimeout {
t.Errorf(
"WriteTimeout (%v) must exceed handler budget (%v)",
srv.WriteTimeout,
server.RequestTimeout,
)
}
}
// TestReadTimeoutCoversHeaderTimeout asserts the read deadline for
// the whole request is at least as long as the header-only deadline;
// a smaller ReadTimeout would make ReadHeaderTimeout unreachable.
func TestReadTimeoutCoversHeaderTimeout(t *testing.T) {
t.Parallel()
srv := server.NewHTTPServer(":8080", noopHandler())
if srv.ReadTimeout < srv.ReadHeaderTimeout {
t.Errorf(
"ReadTimeout (%v) must be >= ReadHeaderTimeout (%v)",
srv.ReadTimeout,
srv.ReadHeaderTimeout,
)
}
}
// TestHTTPServerAddrAndHandler covers the rest of the constructor so
// a future edit cannot drop the listen address or the handler.
func TestHTTPServerAddrAndHandler(t *testing.T) {
t.Parallel()
srv := server.NewHTTPServer(":9999", noopHandler())
if srv.Addr != ":9999" {
t.Errorf("Addr = %q, want %q", srv.Addr, ":9999")
}
if srv.Handler == nil {
t.Error("Handler must not be nil")
}
}