many: reintroduce fdstore helpers

data/systemd/snapd.service.in

@@ -28,6 +28,7 @@ SuccessExitStatus=42
 RestartPreventExitStatus=42
 KillMode=process
 KeyringMode=shared
+FileDescriptorStoreMax=1024
 
 [Install]
 WantedBy=multi-user.target

go.mod

@@ -11,7 +11,6 @@ require (
 	github.com/canonical/go-sp800.90a-drbg v0.0.0-20210314144037-6eeb1040d6c3 // indirect
 	github.com/canonical/go-tpm2 v1.15.0
 	github.com/chai2010/gettext-go v1.0.3
-	github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf
 	github.com/godbus/dbus/v5 v5.1.0
 	github.com/gorilla/mux v1.8.0
 	github.com/gvalkov/golang-evdev v0.0.0-20191114124502-287e62b94bcb

go.sum

@@ -16,8 +16,6 @@ github.com/canonical/tcglog-parser v0.0.0-20240924110432-d15eaf652981 h1:vrUzSfb
 github.com/canonical/tcglog-parser v0.0.0-20240924110432-d15eaf652981/go.mod h1:ywdPBqUGkuuiitPpVWCfilf2/gq+frhq4CNiNs9KyHU=
 github.com/chai2010/gettext-go v1.0.3 h1:9liNh8t+u26xl5ddmWLmsOsdNLwkdRTg5AG+JnTiM80=
 github.com/chai2010/gettext-go v1.0.3/go.mod h1:y+wnP2cHYaVj19NZhYKAwEMH2CI1gNHeQQ+5AjwawxA=
-github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf h1:iW4rZ826su+pqaw19uhpSCzhj44qo35pNgKFGqzDKkU=
-github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/frankban/quicktest v1.2.2 h1:xfmOhhoH5fGPgbEAlhLpJH9p0z/0Qizio9osmvn9IUY=

netutil/activation.go

@@ -24,9 +24,8 @@ import (
 	"net"
 	"os"
 
-	"github.com/coreos/go-systemd/activation"
-
 	"github.com/snapcore/snapd/logger"
+	"github.com/snapcore/snapd/systemd/fdstore"
 )
 
 // GetListener tries to get a listener for the given socket path from the
@@ -73,18 +72,16 @@ func GetListener(socketPath string, listenerMap map[string]net.Listener) (net.Li
 
 // ActivationListeners builds a map of addresses to listeners that were passed
 // during systemd activation
-func ActivationListeners() (lns map[string]net.Listener, err error) {
-	// pass false to keep LISTEN_* environment variables passed by systemd
-	files := activation.Files(false)
-	lns = make(map[string]net.Listener, len(files))
+func ActivationListeners() (listenerByAddr map[string]net.Listener, err error) {
+	listeners, err := fdstore.ActivationListeners()
+	if err != nil {
+		return nil, err
+	}
 
-	for _, f := range files {
-		ln, err := net.FileListener(f)
-		if err != nil {
-			return nil, err
-		}
-		addr := ln.Addr().String()
-		lns[addr] = ln
+	listenerByAddr = make(map[string]net.Listener, len(listeners))
+	for _, listener := range listeners {
+		addr := listener.Addr().String()
+		listenerByAddr[addr] = listener
 	}
-	return lns, nil
+	return listenerByAddr, nil
 }

packaging/debian-sid/control

@@ -22,7 +22,6 @@ Build-Depends: debhelper (>= 13),
                golang-github-bmatcuk-doublestar-dev,
                golang-github-chai2010-gettext-go-dev,
                golang-github-coreos-bbolt-dev,
-               golang-github-coreos-go-systemd-dev,
                golang-github-gorilla-mux-dev,
                golang-github-jessevdk-go-flags-dev,
                golang-github-juju-ratelimit-dev,

packaging/fedora/snapd.spec

@@ -179,7 +179,6 @@ Provides:       %{name}-login-service%{?_isa} = 1.33
 %if ! 0%{?with_bundled}
 BuildRequires: golang(github.com/bmatcuk/doublestar/v4)
 BuildRequires: golang(github.com/chai2010/gettext-go)
-BuildRequires: golang(github.com/coreos/go-systemd/activation)
 BuildRequires: golang(github.com/godbus/dbus/v5)
 BuildRequires: golang(github.com/godbus/dbus/v5/introspect)
 BuildRequires: golang(github.com/gorilla/mux)
@@ -277,7 +276,6 @@ BuildArch:     noarch
 %if ! 0%{?with_bundled}
 Requires:      golang(github.com/bmatcuk/doublestar/v4)
 Requires:      golang(github.com/chai2010/gettext-go)
-Requires:      golang(github.com/coreos/go-systemd/activation)
 Requires:      golang(github.com/godbus/dbus/v5)
 Requires:      golang(github.com/godbus/dbus/v5/introspect)
 Requires:      golang(github.com/gorilla/mux)
@@ -309,7 +307,6 @@ Requires:      golang(gopkg.in/yaml.v3)
 # *sigh*... I hate golang...
 Provides:      bundled(golang(github.com/bmatcuk/doublestar/v4))
 Provides:      bundled(golang(github.com/chai2010/gettext-go))
-Provides:      bundled(golang(github.com/coreos/go-systemd/activation))
 Provides:      bundled(golang(github.com/godbus/dbus/v5))
 Provides:      bundled(golang(github.com/godbus/dbus/v5/introspect))
 Provides:      bundled(golang(github.com/gorilla/mux))

systemd/fdstore/export_test.go

@@ -0,0 +1,63 @@
+// -*- Mode: Go; indent-tabs-mode: t -*-
+
+/*
+ * Copyright (C) 2025 Canonical Ltd
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package fdstore
+
+import (
+	"net"
+	"os"
+
+	"github.com/snapcore/snapd/testutil"
+)
+
+func MockOsGetpid(f func() int) (restore func()) {
+	return testutil.Mock(&osGetpid, f)
+}
+
+func MockUnixCloseOnExec(f func(fd int)) (restore func()) {
+	return testutil.Mock(&unixCloseOnExec, f)
+}
+
+func MockUnixDup(f func(oldfd int) (fd int, err error)) (restore func()) {
+	return testutil.Mock(&unixDup, f)
+}
+
+func MockSdNotify(f func(notifyState string) error) (restore func()) {
+	return testutil.Mock(&sdNotify, f)
+}
+
+func MockSdNotifyWithFds(f func(notifyState string, files ...*os.File) error) (restore func()) {
+	return testutil.Mock(&sdNotifyWithFds, f)
+}
+
+func MockNetFileListener(f func(f *os.File) (ln net.Listener, err error)) (restore func()) {
+	return testutil.Mock(&netFileListener, f)
+}
+
+func MockOsFileClose(f func(*os.File) error) (restore func()) {
+	return testutil.Mock(&osFileClose, f)
+}
+
+func KnownFdNames() map[FdName]bool {
+	return knownFdNames
+}
+
+func Clear() {
+	fdstore = nil
+}