From 1994f382320e627a91e9c510d868c81dd17866bb Mon Sep 17 00:00:00 2001
From: Daniel J Walsh <dwalsh@redhat.com>
Date: Tue, 6 Sep 2022 14:24:34 -0400
Subject: [PATCH] Add --config for Docker compatibility

Fixes: https://github.com/containers/podman/issues/14767

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
---
 cmd/podman/root.go            | 10 ++++++++++
 pkg/domain/entities/engine.go |  1 +
 test/system/001-basic.bats    |  6 ++++++
 3 files changed, 17 insertions(+)

diff --git a/cmd/podman/root.go b/cmd/podman/root.go
index 0261cd6704..2e00777a46 100644
--- a/cmd/podman/root.go
+++ b/cmd/podman/root.go
@@ -73,6 +73,7 @@ var (
 
 	defaultLogLevel = "warn"
 	logLevel        = defaultLogLevel
+	dockerConfig    = ""
 	debug           bool
 
 	useSyslog      bool
@@ -85,6 +86,7 @@ func init() {
 		loggingHook,
 		syslogHook,
 		earlyInitHook,
+		configHook,
 	)
 
 	rootFlags(rootCmd, registry.PodmanConfig())
@@ -311,6 +313,12 @@ func persistentPostRunE(cmd *cobra.Command, args []string) error {
 	return nil
 }
 
+func configHook() {
+	if dockerConfig != "" {
+		logrus.Warn("The --config flag is ignored by Podman. Exists for Docker compatibility")
+	}
+}
+
 func loggingHook() {
 	var found bool
 	if debug {
@@ -363,6 +371,8 @@ func rootFlags(cmd *cobra.Command, opts *entities.PodmanConfig) {
 	lFlags.StringVarP(&opts.URI, "host", "H", uri, "Used for Docker compatibility")
 	_ = lFlags.MarkHidden("host")
 
+	lFlags.StringVar(&dockerConfig, "config", "", "Ignored for Docker compatibility")
+	_ = lFlags.MarkHidden("config")
 	// Context option added just for compatibility with DockerCLI.
 	lFlags.String("context", "default", "Name of the context to use to connect to the daemon (This flag is a NOOP and provided solely for scripting compatibility.)")
 	_ = lFlags.MarkHidden("context")
diff --git a/pkg/domain/entities/engine.go b/pkg/domain/entities/engine.go
index c1a4ffdf35..a69cf51116 100644
--- a/pkg/domain/entities/engine.go
+++ b/pkg/domain/entities/engine.go
@@ -33,6 +33,7 @@ type PodmanConfig struct {
 	*config.Config
 	*pflag.FlagSet
 
+	DockerConfig   string     // Used for Docker compatibility
 	CgroupUsage    string     // rootless code determines Usage message
 	ConmonPath     string     // --conmon flag will set Engine.ConmonPath
 	CPUProfile     string     // Hidden: Should CPU profile be taken
diff --git a/test/system/001-basic.bats b/test/system/001-basic.bats
index 1148aaae7f..e3302bec3b 100644
--- a/test/system/001-basic.bats
+++ b/test/system/001-basic.bats
@@ -29,6 +29,12 @@ function setup() {
     local built=$(expr "$output" : ".*Built: \+\(.*\)" | head -n1)
     local built_t=$(date --date="$built" +%s)
     assert "$built_t" -gt 1546300800 "Preposterous 'Built' time in podman version"
+
+    run_podman -v
+    is "$output" "podman.*version \+"               "'Version line' in output"
+
+    run_podman --config foobar version
+    is "$output" ".*The --config flag is ignored by Podman. Exists for Docker compatibility\+"		  "verify warning for --config option"
 }
 
 @test "podman info" {