cli/connhelper: remove dependency on pkg/process

This package will not be included in the api or client modules, and
we're currently only using a single function of it, and only the
unix implementation, so let's fork it for now (although the package
may be moved to moby/sys).

This removes the last dependency on github.com/docker/docker.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/connhelper/commandconn/commandconn_unix_test.go

@@ -4,12 +4,17 @@ package commandconn
 
 import (
 	"context"
+	"errors"
 	"io"
 	"io/fs"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"syscall"
 	"testing"
 	"time"
 
-	"github.com/docker/docker/pkg/process"
 	"gotest.tools/v3/assert"
 	is "gotest.tools/v3/assert/cmp"
 )
@@ -51,16 +56,16 @@ func TestCloseRunningCommand(t *testing.T) {
 		c, err := New(ctx, "sh", "-c", "while true; do sleep 1; done")
 		assert.NilError(t, err)
 		cmdConn := c.(*commandConn)
-		assert.Check(t, process.Alive(cmdConn.cmd.Process.Pid))
+		assert.Check(t, processAlive(cmdConn.cmd.Process.Pid))
 
 		n, err := c.Write([]byte("hello"))
 		assert.Check(t, is.Equal(len("hello"), n))
 		assert.NilError(t, err)
-		assert.Check(t, process.Alive(cmdConn.cmd.Process.Pid))
+		assert.Check(t, processAlive(cmdConn.cmd.Process.Pid))
 
 		err = cmdConn.Close()
 		assert.NilError(t, err)
-		assert.Check(t, !process.Alive(cmdConn.cmd.Process.Pid))
+		assert.Check(t, !processAlive(cmdConn.cmd.Process.Pid))
 		done <- struct{}{}
 	}()
 
@@ -79,7 +84,7 @@ func TestCloseTwice(t *testing.T) {
 		c, err := New(ctx, "sh", "-c", "echo hello; sleep 1; exit 0")
 		assert.NilError(t, err)
 		cmdConn := c.(*commandConn)
-		assert.Check(t, process.Alive(cmdConn.cmd.Process.Pid))
+		assert.Check(t, processAlive(cmdConn.cmd.Process.Pid))
 
 		b := make([]byte, 32)
 		n, err := c.Read(b)
@@ -88,11 +93,11 @@ func TestCloseTwice(t *testing.T) {
 
 		err = cmdConn.Close()
 		assert.NilError(t, err)
-		assert.Check(t, !process.Alive(cmdConn.cmd.Process.Pid))
+		assert.Check(t, !processAlive(cmdConn.cmd.Process.Pid))
 
 		err = cmdConn.Close()
 		assert.NilError(t, err)
-		assert.Check(t, !process.Alive(cmdConn.cmd.Process.Pid))
+		assert.Check(t, !processAlive(cmdConn.cmd.Process.Pid))
 		done <- struct{}{}
 	}()
 
@@ -111,7 +116,7 @@ func TestEOFTimeout(t *testing.T) {
 		c, err := New(ctx, "sh", "-c", "sleep 20")
 		assert.NilError(t, err)
 		cmdConn := c.(*commandConn)
-		assert.Check(t, process.Alive(cmdConn.cmd.Process.Pid))
+		assert.Check(t, processAlive(cmdConn.cmd.Process.Pid))
 
 		cmdConn.stdout = mockStdoutEOF{}
 
@@ -148,7 +153,7 @@ func TestCloseWhileWriting(t *testing.T) {
 	c, err := New(ctx, "sh", "-c", "while true; do sleep 1; done")
 	assert.NilError(t, err)
 	cmdConn := c.(*commandConn)
-	assert.Check(t, process.Alive(cmdConn.cmd.Process.Pid))
+	assert.Check(t, processAlive(cmdConn.cmd.Process.Pid))
 
 	writeErrC := make(chan error)
 	go func() {
@@ -164,7 +169,7 @@ func TestCloseWhileWriting(t *testing.T) {
 
 	err = c.Close()
 	assert.NilError(t, err)
-	assert.Check(t, !process.Alive(cmdConn.cmd.Process.Pid))
+	assert.Check(t, !processAlive(cmdConn.cmd.Process.Pid))
 
 	writeErr := <-writeErrC
 	assert.ErrorContains(t, writeErr, "file already closed")
@@ -176,7 +181,7 @@ func TestCloseWhileReading(t *testing.T) {
 	c, err := New(ctx, "sh", "-c", "while true; do sleep 1; done")
 	assert.NilError(t, err)
 	cmdConn := c.(*commandConn)
-	assert.Check(t, process.Alive(cmdConn.cmd.Process.Pid))
+	assert.Check(t, processAlive(cmdConn.cmd.Process.Pid))
 
 	readErrC := make(chan error)
 	go func() {
@@ -193,8 +198,37 @@ func TestCloseWhileReading(t *testing.T) {
 
 	err = cmdConn.Close()
 	assert.NilError(t, err)
-	assert.Check(t, !process.Alive(cmdConn.cmd.Process.Pid))
+	assert.Check(t, !processAlive(cmdConn.cmd.Process.Pid))
 
 	readErr := <-readErrC
 	assert.Check(t, is.ErrorIs(readErr, fs.ErrClosed))
 }
+
+// processAlive returns true if a process with a given pid is running. It only considers
+// positive PIDs; 0 (all processes in the current process group), -1 (all processes
+// with a PID larger than 1), and negative (-n, all processes in process group
+// "n") values for pid are never considered to be alive.
+//
+// It was forked from https://github.com/moby/moby/blob/v28.3.3/pkg/process/process_unix.go#L17-L42
+func processAlive(pid int) bool {
+	if pid < 1 {
+		return false
+	}
+	switch runtime.GOOS {
+	case "darwin":
+		// OS X does not have a proc filesystem. Use kill -0 pid to judge if the
+		// process exists. From KILL(2): https://www.freebsd.org/cgi/man.cgi?query=kill&sektion=2&manpath=OpenDarwin+7.2.1
+		//
+		// Sig may be one of the signals specified in sigaction(2) or it may
+		// be 0, in which case error checking is performed but no signal is
+		// actually sent. This can be used to check the validity of pid.
+		err := syscall.Kill(pid, 0)
+
+		// Either the PID was found (no error), or we get an EPERM, which means
+		// the PID exists, but we don't have permissions to signal it.
+		return err == nil || errors.Is(err, syscall.EPERM)
+	default:
+		_, err := os.Stat(filepath.Join("/proc", strconv.Itoa(pid)))
+		return err == nil
+	}
+}

vendor.mod

@@ -22,7 +22,6 @@ require (
 	github.com/distribution/reference v0.6.0
 	github.com/docker/cli-docs-tool v0.10.0
 	github.com/docker/distribution v2.8.3+incompatible
-	github.com/docker/docker v28.2.3-0.20250731152656-4faedf2bec36+incompatible // master (v29.0-dev)
 	github.com/docker/docker-credential-helpers v0.9.3
 	github.com/docker/go-connections v0.5.0
 	github.com/docker/go-units v0.5.0

vendor.sum

@@ -57,8 +57,6 @@ github.com/docker/cli-docs-tool v0.10.0/go.mod h1:5EM5zPnT2E7yCLERZmrDA234Vwn09f
 github.com/docker/distribution v2.7.1+incompatible/go.mod h1:J2gT2udsDAN96Uj4KfcMRqY0/ypR+oyYUYmja8H+y+w=
 github.com/docker/distribution v2.8.3+incompatible h1:AtKxIZ36LoNK51+Z6RpzLpddBirtxJnzDrHLEKxTAYk=
 github.com/docker/distribution v2.8.3+incompatible/go.mod h1:J2gT2udsDAN96Uj4KfcMRqY0/ypR+oyYUYmja8H+y+w=
-github.com/docker/docker v28.2.3-0.20250731152656-4faedf2bec36+incompatible h1:V1yo9808DrQaHES6Q3hW5Rtd44+mrc4oKulmzPgRDAM=
-github.com/docker/docker v28.2.3-0.20250731152656-4faedf2bec36+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
 github.com/docker/docker-credential-helpers v0.9.3 h1:gAm/VtF9wgqJMoxzT3Gj5p4AqIjCBS4wrsOh9yRqcz8=
 github.com/docker/docker-credential-helpers v0.9.3/go.mod h1:x+4Gbw9aGmChi3qTLZj8Dfn0TD20M/fuWy0E5+WDeCo=
 github.com/docker/go v1.5.1-1.0.20160303222718-d30aec9fd63c h1:lzqkGL9b3znc+ZUgi7FlLnqjQhcXxkNM/quxIjBVMD0=

vendor/github.com/docker/docker/LICENSE

@@ -1,191 +0,0 @@
-
-                                 Apache License
-                           Version 2.0, January 2004
-                        https://www.apache.org/licenses/
-
-   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
-
-   1. Definitions.
-
-      "License" shall mean the terms and conditions for use, reproduction,
-      and distribution as defined by Sections 1 through 9 of this document.
-
-      "Licensor" shall mean the copyright owner or entity authorized by
-      the copyright owner that is granting the License.
-
-      "Legal Entity" shall mean the union of the acting entity and all
-      other entities that control, are controlled by, or are under common
-      control with that entity. For the purposes of this definition,
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-      direction or management of such entity, whether by contract or
-      otherwise, or (ii) ownership of fifty percent (50%) or more of the
-      outstanding shares, or (iii) beneficial ownership of such entity.
-
-      "You" (or "Your") shall mean an individual or Legal Entity
-      exercising permissions granted by this License.
-
-      "Source" form shall mean the preferred form for making modifications,
-      including but not limited to software source code, documentation
-      source, and configuration files.
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-      "Object" form shall mean any form resulting from mechanical
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-      and conversions to other media types.
-
-      "Work" shall mean the work of authorship, whether in Source or
-      Object form, made available under the License, as indicated by a
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-      editorial revisions, annotations, elaborations, or other modifications
-      represent, as a whole, an original work of authorship. For the purposes
-      of this License, Derivative Works shall not include works that remain
-      separable from, or merely link (or bind by name) to the interfaces of,
-      the Work and Derivative Works thereof.
-
-      "Contribution" shall mean any work of authorship, including
-      the original version of the Work and any modifications or additions
-      to that Work or Derivative Works thereof, that is intentionally
-      submitted to Licensor for inclusion in the Work by the copyright owner
-      or by an individual or Legal Entity authorized to submit on behalf of
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-      to the Licensor or its representatives, including but not limited to
-      communication on electronic mailing lists, source code control systems,
-      and issue tracking systems that are managed by, or on behalf of, the
-      Licensor for the purpose of discussing and improving the Work, but
-      excluding communication that is conspicuously marked or otherwise
-      designated in writing by the copyright owner as "Not a Contribution."
-
-      "Contributor" shall mean Licensor and any individual or Legal Entity
-      on behalf of whom a Contribution has been received by Licensor and
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-   2. Grant of Copyright License. Subject to the terms and conditions of
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-      copyright license to reproduce, prepare Derivative Works of,
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-      (except as stated in this section) patent license to make, have made,
-      use, offer to sell, sell, import, and otherwise transfer the Work,
-      where such license applies only to those patent claims licensable
-      by such Contributor that are necessarily infringed by their
-      Contribution(s) alone or by combination of their Contribution(s)
-      with the Work to which such Contribution(s) was submitted. If You
-      institute patent litigation against any entity (including a
-      cross-claim or counterclaim in a lawsuit) alleging that the Work
-      or a Contribution incorporated within the Work constitutes direct
-      or contributory patent infringement, then any patent licenses
-      granted to You under this License for that Work shall terminate
-      as of the date such litigation is filed.
-
-   4. Redistribution. You may reproduce and distribute copies of the
-      Work or Derivative Works thereof in any medium, with or without
-      modifications, and in Source or Object form, provided that You
-      meet the following conditions:
-
-      (a) You must give any other recipients of the Work or
-          Derivative Works a copy of this License; and
-
-      (b) You must cause any modified files to carry prominent notices
-          stating that You changed the files; and
-
-      (c) You must retain, in the Source form of any Derivative Works
-          that You distribute, all copyright, patent, trademark, and
-          attribution notices from the Source form of the Work,
-          excluding those notices that do not pertain to any part of
-          the Derivative Works; and
-
-      (d) If the Work includes a "NOTICE" text file as part of its
-          distribution, then any Derivative Works that You distribute must
-          include a readable copy of the attribution notices contained
-          within such NOTICE file, excluding those notices that do not
-          pertain to any part of the Derivative Works, in at least one
-          of the following places: within a NOTICE text file distributed
-          as part of the Derivative Works; within the Source form or
-          documentation, if provided along with the Derivative Works; or,
-          within a display generated by the Derivative Works, if and
-          wherever such third-party notices normally appear. The contents
-          of the NOTICE file are for informational purposes only and
-          do not modify the License. You may add Your own attribution
-          notices within Derivative Works that You distribute, alongside
-          or as an addendum to the NOTICE text from the Work, provided
-          that such additional attribution notices cannot be construed
-          as modifying the License.
-
-      You may add Your own copyright statement to Your modifications and
-      may provide additional or different license terms and conditions
-      for use, reproduction, or distribution of Your modifications, or
-      for any such Derivative Works as a whole, provided Your use,
-      reproduction, and distribution of the Work otherwise complies with
-      the conditions stated in this License.
-
-   5. Submission of Contributions. Unless You explicitly state otherwise,
-      any Contribution intentionally submitted for inclusion in the Work
-      by You to the Licensor shall be under the terms and conditions of
-      this License, without any additional terms or conditions.
-      Notwithstanding the above, nothing herein shall supersede or modify
-      the terms of any separate license agreement you may have executed
-      with Licensor regarding such Contributions.
-
-   6. Trademarks. This License does not grant permission to use the trade
-      names, trademarks, service marks, or product names of the Licensor,
-      except as required for reasonable and customary use in describing the
-      origin of the Work and reproducing the content of the NOTICE file.
-
-   7. Disclaimer of Warranty. Unless required by applicable law or
-      agreed to in writing, Licensor provides the Work (and each
-      Contributor provides its Contributions) on an "AS IS" BASIS,
-      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
-      implied, including, without limitation, any warranties or conditions
-      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
-      PARTICULAR PURPOSE. You are solely responsible for determining the
-      appropriateness of using or redistributing the Work and assume any
-      risks associated with Your exercise of permissions under this License.
-
-   8. Limitation of Liability. In no event and under no legal theory,
-      whether in tort (including negligence), contract, or otherwise,
-      unless required by applicable law (such as deliberate and grossly
-      negligent acts) or agreed to in writing, shall any Contributor be
-      liable to You for damages, including any direct, indirect, special,
-      incidental, or consequential damages of any character arising as a
-      result of this License or out of the use or inability to use the
-      Work (including but not limited to damages for loss of goodwill,
-      work stoppage, computer failure or malfunction, or any and all
-      other commercial damages or losses), even if such Contributor
-      has been advised of the possibility of such damages.
-
-   9. Accepting Warranty or Additional Liability. While redistributing
-      the Work or Derivative Works thereof, You may choose to offer,
-      and charge a fee for, acceptance of support, warranty, indemnity,
-      or other liability obligations and/or rights consistent with this
-      License. However, in accepting such obligations, You may act only
-      on Your own behalf and on Your sole responsibility, not on behalf
-      of any other Contributor, and only if You agree to indemnify,
-      defend, and hold each Contributor harmless for any liability
-      incurred by, or claims asserted against, such Contributor by reason
-      of your accepting any such warranty or additional liability.
-
-   END OF TERMS AND CONDITIONS
-
-   Copyright 2013-2018 Docker, Inc.
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       https://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.

vendor/github.com/docker/docker/NOTICE

@@ -1,19 +0,0 @@
-Docker
-Copyright 2012-2017 Docker, Inc.
-
-This product includes software developed at Docker, Inc. (https://www.docker.com).
-
-This product contains software (https://github.com/creack/pty) developed
-by Keith Rarick, licensed under the MIT License.
-
-The following is courtesy of our legal counsel:
-
-
-Use and transfer of Docker may be subject to certain restrictions by the
-United States and other governments.
-It is your responsibility to ensure that your use and/or transfer does not
-violate applicable laws.
-
-For more information, please see https://www.bis.doc.gov
-
-See also https://www.apache.org/dev/crypto.html and/or seek legal counsel.

vendor/github.com/docker/docker/pkg/process/doc.go

@@ -1,3 +0,0 @@
-// Package process provides a set of basic functions to manage individual
-// processes.
-package process

vendor/github.com/docker/docker/pkg/process/process.go

@@ -1,29 +0,0 @@
-package process
-
-import "fmt"
-
-// Alive returns true if process with a given pid is running.
-//
-// It only considers positive PIDs; 0 (all processes in the current process
-// group), -1 (all processes with a PID larger than 1), and negative (-n,
-// all processes in process group "n") values for pid are never considered
-// to be alive.
-func Alive(pid int) bool {
-	if pid < 1 {
-		return false
-	}
-	return alive(pid)
-}
-
-// Kill force-stops a process. It only allows positive PIDs; 0 (all processes
-// in the current process group), -1 (all processes with a PID larger than 1),
-// and negative (-n, all processes in process group "n") values for pid producs
-// an error. Refer to [KILL(2)] for details.
-//
-// [KILL(2)]: https://man7.org/linux/man-pages/man2/kill.2.html
-func Kill(pid int) error {
-	if pid < 1 {
-		return fmt.Errorf("invalid PID (%d): only positive PIDs are allowed", pid)
-	}
-	return kill(pid)
-}

vendor/github.com/docker/docker/pkg/process/process_linux.go

@@ -1,24 +0,0 @@
-package process
-
-import (
-	"bytes"
-	"fmt"
-	"os"
-)
-
-func zombie(pid int) (bool, error) {
-	if pid < 1 {
-		return false, nil
-	}
-	data, err := os.ReadFile(fmt.Sprintf("/proc/%d/stat", pid))
-	if err != nil {
-		if os.IsNotExist(err) {
-			return false, nil
-		}
-		return false, err
-	}
-	if cols := bytes.SplitN(data, []byte(" "), 4); len(cols) >= 3 && string(cols[2]) == "Z" {
-		return true, nil
-	}
-	return false, nil
-}

vendor/github.com/docker/docker/pkg/process/process_nolinux.go

@@ -1,7 +0,0 @@
-//go:build !linux
-
-package process
-
-func zombie(pid int) (bool, error) {
-	return false, nil
-}

vendor/github.com/docker/docker/pkg/process/process_unix.go

@@ -1,53 +0,0 @@
-//go:build !windows
-
-package process
-
-import (
-	"errors"
-	"os"
-	"path/filepath"
-	"runtime"
-	"strconv"
-
-	"golang.org/x/sys/unix"
-)
-
-func alive(pid int) bool {
-	switch runtime.GOOS {
-	case "darwin":
-		// macOS does not have a proc filesystem. Use kill -0 pid to judge if the
-		// process exists. From KILL(2): https://www.freebsd.org/cgi/man.cgi?query=kill&sektion=2&manpath=OpenDarwin+7.2.1
-		//
-		// Sig may be one of the signals specified in sigaction(2) or it may
-		// be 0, in which case error checking is performed but no signal is
-		// actually sent. This can be used to check the validity of pid.
-		err := unix.Kill(pid, 0)
-
-		// Either the PID was found (no error) or we get an EPERM, which means
-		// the PID exists, but we don't have permissions to signal it.
-		return err == nil || errors.Is(err, unix.EPERM)
-	default:
-		_, err := os.Stat(filepath.Join("/proc", strconv.Itoa(pid)))
-		return err == nil
-	}
-}
-
-func kill(pid int) error {
-	err := unix.Kill(pid, unix.SIGKILL)
-	if err != nil && !errors.Is(err, unix.ESRCH) {
-		return err
-	}
-	return nil
-}
-
-// Zombie return true if process has a state with "Z". It only considers positive
-// PIDs; 0 (all processes in the current process group), -1 (all processes with
-// a PID larger than 1), and negative (-n, all processes in process group "n")
-// values for pid are ignored. Refer to [PROC(5)] for details.
-//
-// Zombie is only implemented on Linux, and returns false on all other platforms.
-//
-// [PROC(5)]: https://man7.org/linux/man-pages/man5/proc.5.html
-func Zombie(pid int) (bool, error) {
-	return zombie(pid)
-}

vendor/github.com/docker/docker/pkg/process/process_windows.go

@@ -1,43 +0,0 @@
-package process
-
-import (
-	"os"
-
-	"golang.org/x/sys/windows"
-)
-
-func alive(pid int) bool {
-	h, err := windows.OpenProcess(windows.PROCESS_QUERY_LIMITED_INFORMATION, false, uint32(pid))
-	if err != nil {
-		return false
-	}
-	var c uint32
-	err = windows.GetExitCodeProcess(h, &c)
-	_ = windows.CloseHandle(h)
-	if err != nil {
-		// From the GetExitCodeProcess function (processthreadsapi.h) API docs:
-		// https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-getexitcodeprocess
-		//
-		// The GetExitCodeProcess function returns a valid error code defined by the
-		// application only after the thread terminates. Therefore, an application should
-		// not use STILL_ACTIVE (259) as an error code (STILL_ACTIVE is a macro for
-		// STATUS_PENDING (minwinbase.h)). If a thread returns STILL_ACTIVE (259) as
-		// an error code, then applications that test for that value could interpret it
-		// to mean that the thread is still running, and continue to test for the
-		// completion of the thread after the thread has terminated, which could put
-		// the application into an infinite loop.
-		return c == uint32(windows.STATUS_PENDING)
-	}
-	return true
-}
-
-func kill(pid int) error {
-	p, err := os.FindProcess(pid)
-	if err == nil {
-		err = p.Kill()
-		if err != nil && err != os.ErrProcessDone {
-			return err
-		}
-	}
-	return nil
-}

vendor/modules.txt

@@ -65,9 +65,6 @@ github.com/docker/distribution/registry/client/transport
 github.com/docker/distribution/registry/storage/cache
 github.com/docker/distribution/registry/storage/cache/memory
 github.com/docker/distribution/uuid
-# github.com/docker/docker v28.2.3-0.20250731152656-4faedf2bec36+incompatible
-## explicit
-github.com/docker/docker/pkg/process
 # github.com/docker/docker-credential-helpers v0.9.3
 ## explicit; go 1.21
 github.com/docker/docker-credential-helpers/client