docs: use defer instead of os.Exit(m.Run())

as of go1.15 `testing.M` returns the return code of `m.Run()`, so it is
possible to use `defer`
golang/go#34129

README.md

@@ -100,14 +100,15 @@ func TestMain(m *testing.M) {
 		log.Fatalf("Could not connect to database: %s", err)
 	}
 
-	code := m.Run()
+	// as of go1.15 testing.M returns the exit code of m.Run(), so it is safe to use defer here
+    defer func() {
+      if err := pool.Purge(resource); err != nil {
+        log.Fatalf("Could not purge resource: %s", err)
+      }
 
-	// You can't defer this because os.Exit doesn't care for defer
-	if err := pool.Purge(resource); err != nil {
-		log.Fatalf("Could not purge resource: %s", err)
-	}
+    }()
 
-	os.Exit(code)
+	m.Run()
 }
 
 func TestSomething(t *testing.T) {

docker/auth.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2015 go-dockerclient authors. All rights reserved.

docker/change.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2014 go-dockerclient authors. All rights reserved.

docker/client.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2013 go-dockerclient authors. All rights reserved.

docker/client_unix.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2016 go-dockerclient authors. All rights reserved.

docker/client_windows.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2016 go-dockerclient authors. All rights reserved.

docker/container.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2013 go-dockerclient authors. All rights reserved.

docker/distribution.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2017 go-dockerclient authors. All rights reserved.

docker/env.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2014 Docker authors. All rights reserved.

docker/event.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2014 go-dockerclient authors. All rights reserved.

docker/exec.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2014 go-dockerclient authors. All rights reserved.

docker/image.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2013 go-dockerclient authors. All rights reserved.

docker/misc.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2013 go-dockerclient authors. All rights reserved.
@@ -85,7 +85,7 @@ type DockerInfo struct {
 	InitBinary         string
 	DefaultRuntime     string
 	LiveRestoreEnabled bool
-	//Swarm              swarm.Info
+	// Swarm              swarm.Info
 }
 
 // PluginsInfo is a struct with the plugins registered with the docker daemon

docker/network.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 // Copyright 2015 go-dockerclient authors. All rights reserved.

docker/opts/env.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package opts

docker/opts/hosts.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package opts

docker/opts/hosts_unix.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 //go:build !windows

docker/opts/hosts_windows.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package opts

docker/opts/ip.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package opts

docker/opts/opts.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package opts

docker/opts/opts_unix.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 //go:build !windows

docker/opts/opts_windows.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package opts

docker/opts/quotedstring.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package opts

docker/opts/runtime.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package opts

docker/opts/ulimit.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package opts

docker/pkg/archive/archive.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package archive // import "github.com/ory/dockertest/v3/docker/pkg/archive"
@@ -21,12 +21,13 @@ import (
 	"strings"
 	"syscall"
 
+	"github.com/sirupsen/logrus"
+
 	"github.com/ory/dockertest/v3/docker/pkg/fileutils"
 	"github.com/ory/dockertest/v3/docker/pkg/idtools"
 	"github.com/ory/dockertest/v3/docker/pkg/ioutils"
 	"github.com/ory/dockertest/v3/docker/pkg/pools"
 	"github.com/ory/dockertest/v3/docker/pkg/system"
-	"github.com/sirupsen/logrus"
 )
 
 var unpigzPath string
@@ -499,13 +500,13 @@ func (ta *tarAppender) addTarFile(path, name string) error {
 		}
 	}
 
-	//check whether the file is overlayfs whiteout
-	//if yes, skip re-mapping container ID mappings.
+	// check whether the file is overlayfs whiteout
+	// if yes, skip re-mapping container ID mappings.
 	isOverlayWhiteout := fi.Mode()&os.ModeCharDevice != 0 && hdr.Devmajor == 0 && hdr.Devminor == 0
 
-	//handle re-mapping container ID mappings back to host ID mappings before
-	//writing tar headers/files. We skip whiteout files because they were written
-	//by the kernel and already have proper ownership relative to the host
+	// handle re-mapping container ID mappings back to host ID mappings before
+	// writing tar headers/files. We skip whiteout files because they were written
+	// by the kernel and already have proper ownership relative to the host
 	if !isOverlayWhiteout &&
 		!strings.HasPrefix(filepath.Base(hdr.Name), WhiteoutPrefix) &&
 		!ta.IDMappings.Empty() {

docker/pkg/archive/archive_linux.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package archive // import "github.com/ory/dockertest/v3/docker/pkg/archive"
@@ -9,8 +9,9 @@ import (
 	"path/filepath"
 	"strings"
 
-	"github.com/ory/dockertest/v3/docker/pkg/system"
 	"golang.org/x/sys/unix"
+
+	"github.com/ory/dockertest/v3/docker/pkg/system"
 )
 
 func getWhiteoutConverter(format WhiteoutFormat) tarWhiteoutConverter {

docker/pkg/archive/archive_other.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 //go:build !linux

docker/pkg/archive/archive_unix.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 //go:build !windows
@@ -15,9 +15,10 @@ import (
 	"path/filepath"
 	"syscall"
 
+	"golang.org/x/sys/unix"
+
 	"github.com/ory/dockertest/v3/docker/pkg/idtools"
 	"github.com/ory/dockertest/v3/docker/pkg/system"
-	"golang.org/x/sys/unix"
 )
 
 // fixVolumePathPrefix does platform specific processing to ensure that if

docker/pkg/archive/archive_windows.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package archive // import "github.com/ory/dockertest/v3/docker/pkg/archive"
@@ -44,7 +44,7 @@ func CanonicalTarNameForPath(p string) (string, error) {
 // chmodTarEntry is used to adjust the file permissions used in tar header based
 // on the platform the archival is done.
 func chmodTarEntry(perm os.FileMode) os.FileMode {
-	//perm &= 0755 // this 0-ed out tar flags (like link, regular file, directory marker etc.)
+	// perm &= 0755 // this 0-ed out tar flags (like link, regular file, directory marker etc.)
 	permPart := perm & os.ModePerm
 	noPermPart := perm &^ os.ModePerm
 	// Add the x bit: make everything +x from windows

docker/pkg/archive/changes.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package archive // import "github.com/ory/dockertest/v3/docker/pkg/archive"
@@ -16,10 +16,11 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/sirupsen/logrus"
+
 	"github.com/ory/dockertest/v3/docker/pkg/idtools"
 	"github.com/ory/dockertest/v3/docker/pkg/pools"
 	"github.com/ory/dockertest/v3/docker/pkg/system"
-	"github.com/sirupsen/logrus"
 )
 
 // ChangeType represents the change type.

docker/pkg/archive/changes_linux.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package archive // import "github.com/ory/dockertest/v3/docker/pkg/archive"
@@ -12,8 +12,9 @@ import (
 	"syscall"
 	"unsafe"
 
-	"github.com/ory/dockertest/v3/docker/pkg/system"
 	"golang.org/x/sys/unix"
+
+	"github.com/ory/dockertest/v3/docker/pkg/system"
 )
 
 // walker is used to implement collectFileInfoForChanges on linux. Where this

docker/pkg/archive/changes_other.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 //go:build !linux

docker/pkg/archive/changes_unix.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 //go:build !windows
@@ -10,8 +10,9 @@ import (
 	"os"
 	"syscall"
 
-	"github.com/ory/dockertest/v3/docker/pkg/system"
 	"golang.org/x/sys/unix"
+
+	"github.com/ory/dockertest/v3/docker/pkg/system"
 )
 
 func statDifferent(oldStat *system.StatT, newStat *system.StatT) bool {

docker/pkg/archive/changes_windows.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package archive // import "github.com/ory/dockertest/v3/docker/pkg/archive"

docker/pkg/archive/copy.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package archive // import "github.com/ory/dockertest/v3/docker/pkg/archive"
@@ -12,8 +12,9 @@ import (
 	"path/filepath"
 	"strings"
 
-	"github.com/ory/dockertest/v3/docker/pkg/system"
 	"github.com/sirupsen/logrus"
+
+	"github.com/ory/dockertest/v3/docker/pkg/system"
 )
 
 // Errors used or returned by this file.

docker/pkg/archive/copy_unix.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 //go:build !windows

docker/pkg/archive/copy_windows.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package archive // import "github.com/ory/dockertest/v3/docker/pkg/archive"

docker/pkg/archive/diff.go

@@ -1,4 +1,4 @@
-// Copyright © 2023 Ory Corp
+// Copyright © 2024 Ory Corp
 // SPDX-License-Identifier: Apache-2.0
 
 package archive // import "github.com/ory/dockertest/v3/docker/pkg/archive"
@@ -13,10 +13,11 @@ import (
 	"runtime"
 	"strings"
 
+	"github.com/sirupsen/logrus"
+
 	"github.com/ory/dockertest/v3/docker/pkg/idtools"
 	"github.com/ory/dockertest/v3/docker/pkg/pools"
 	"github.com/ory/dockertest/v3/docker/pkg/system"
-	"github.com/sirupsen/logrus"
 )
 
 // UnpackLayer unpack `layer` to a `dest`. The stream `layer` can be