Add option --unsetenv to remove default environment variables

cmd/podman/common/create.go

@@ -201,6 +201,20 @@ func DefineCreateFlags(cmd *cobra.Command, cf *entities.ContainerCreateOptions,
 		)
 		_ = cmd.RegisterFlagCompletionFunc(envFlagName, completion.AutocompleteNone)
 
+		unsetenvFlagName := "unsetenv"
+		createFlags.StringArrayVar(
+			&cf.UnsetEnv,
+			unsetenvFlagName, []string{},
+			"Unset environment default variables in container",
+		)
+		_ = cmd.RegisterFlagCompletionFunc(unsetenvFlagName, completion.AutocompleteNone)
+
+		createFlags.BoolVar(
+			&cf.UnsetEnvAll,
+			"unsetenv-all", false,
+			"Unset all default environment variables in container",
+		)
+
 		if !registry.IsRemote() {
 			createFlags.BoolVar(
 				&cf.EnvHost,

cmd/podman/common/create_opts.go

@@ -297,6 +297,8 @@ func ContainerCreateToContainerCLIOpts(cc handlers.CreateContainerConfig, rtc *c
 		Systemd:           "true", // podman default
 		TmpFS:             parsedTmp,
 		TTY:               cc.Config.Tty,
+		UnsetEnv:          cc.UnsetEnv,
+		UnsetEnvAll:       cc.UnsetEnvAll,
 		User:              cc.Config.User,
 		UserNS:            string(cc.HostConfig.UsernsMode),
 		UTS:               string(cc.HostConfig.UTSMode),

docs/source/markdown/podman-create.1.md

@@ -1047,6 +1047,18 @@ Remote connections use local containers.conf for defaults
 Set the umask inside the container. Defaults to `0022`.
 Remote connections use local containers.conf for defaults
 
+#### **--unsetenv**=*env*
+
+Unset default environment variables for the container. Default environment
+variables include variables provided natively by Podman, environment variables
+configured by the image, and environment variables from containers.conf.
+
+#### **--unsetenv-all**=*true|false*
+
+Unset all default environment variables for the container. Default environment
+variables include variables provided natively by Podman, environment variables
+configured by the image, and environment variables from containers.conf.
+
 #### **--uidmap**=*container_uid*:*from_uid*:*amount*
 
 Run the container in a new user namespace using the supplied mapping. This

docs/source/markdown/podman-run.1.md

@@ -1117,6 +1117,18 @@ Remote connections use local containers.conf for defaults
 Set the umask inside the container. Defaults to `0022`.
 Remote connections use local containers.conf for defaults
 
+#### **--unsetenv**=*env*
+
+Unset default environment variables for the container. Default environment
+variables include variables provided natively by Podman, environment variables
+configured by the image, and environment variables from containers.conf.
+
+#### **--unsetenv-all**=*true|false*
+
+Unset all default environment variables for the container. Default environment
+variables include variables provided natively by Podman, environment variables
+configured by the image, and environment variables from containers.conf.
+
 #### **--uidmap**=*container_uid*:*from_uid*:*amount*
 
 Run the container in a new user namespace using the supplied mapping. This

libpod/container_inspect.go

@@ -300,8 +300,7 @@ func (c *Container) generateInspectContainerConfig(spec *spec.Spec) *define.Insp
 	ctrConfig.User = c.config.User
 	if spec.Process != nil {
 		ctrConfig.Tty = spec.Process.Terminal
-		ctrConfig.Env = []string{}
-		ctrConfig.Env = append(ctrConfig.Env, spec.Process.Env...)
+		ctrConfig.Env = append([]string{}, spec.Process.Env...)
 		ctrConfig.WorkingDir = spec.Process.Cwd
 	}
 

libpod/container_internal_linux.go

@@ -709,18 +709,6 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) {
 		g.AddAnnotation(annotations.ContainerManager, annotations.ContainerManagerLibpod)
 	}
 
-	// Only add container environment variable if not already present
-	foundContainerEnv := false
-	for _, env := range g.Config.Process.Env {
-		if strings.HasPrefix(env, "container=") {
-			foundContainerEnv = true
-			break
-		}
-	}
-	if !foundContainerEnv {
-		g.AddProcessEnv("container", "libpod")
-	}
-
 	cgroupPath, err := c.getOCICgroupPath()
 	if err != nil {
 		return nil, err

pkg/api/handlers/types.go

@@ -116,6 +116,8 @@ type CreateContainerConfig struct {
 	dockerContainer.Config                                // desired container configuration
 	HostConfig             dockerContainer.HostConfig     // host dependent configuration for container
 	NetworkingConfig       dockerNetwork.NetworkingConfig // network configuration for container
+	UnsetEnv               []string                       // unset specified default environment variables
+	UnsetEnvAll            bool                           // unset all default environment variables
 }
 
 // swagger:model IDResponse

pkg/domain/entities/pods.go

@@ -248,6 +248,8 @@ type ContainerCreateOptions struct {
 	TTY               bool
 	Timezone          string
 	Umask             string
+	UnsetEnv          []string
+	UnsetEnvAll       bool
 	UIDMap            []string
 	Ulimit            []string
 	User              string

pkg/specgen/generate/container.go

@@ -88,9 +88,6 @@ func CompleteSpec(ctx context.Context, r *libpod.Runtime, s *specgen.SpecGenerat
 	if err != nil {
 		return nil, errors.Wrap(err, "error parsing fields in containers.conf")
 	}
-	if defaultEnvs["container"] == "" {
-		defaultEnvs["container"] = "podman"
-	}
 	var envs map[string]string
 
 	// Image Environment defaults
@@ -101,9 +98,16 @@ func CompleteSpec(ctx context.Context, r *libpod.Runtime, s *specgen.SpecGenerat
 		if err != nil {
 			return nil, errors.Wrap(err, "Env fields from image failed to parse")
 		}
-		defaultEnvs = envLib.Join(defaultEnvs, envs)
+		defaultEnvs = envLib.Join(envLib.DefaultEnvVariables(), envLib.Join(defaultEnvs, envs))
+	}
+
+	for _, e := range s.UnsetEnv {
+		delete(defaultEnvs, e)
 	}
 
+	if s.UnsetEnvAll {
+		defaultEnvs = make(map[string]string)
+	}
 	// First transform the os env into a map. We need it for the labels later in
 	// any case.
 	osEnv, err := envLib.ParseSlice(os.Environ())

pkg/specgen/generate/oci.go

@@ -298,7 +298,6 @@ func SpecGenToOCI(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Runt
 	for key, val := range s.Annotations {
 		g.AddAnnotation(key, val)
 	}
-	g.AddProcessEnv("container", "podman")
 
 	g.Config.Linux.Resources = s.ResourceLimits
 	// Devices
@@ -332,6 +331,7 @@ func SpecGenToOCI(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.Runt
 
 	BlockAccessToKernelFilesystems(s.Privileged, s.PidNS.IsHost(), s.Mask, s.Unmask, &g)
 
+	g.ClearProcessEnv()
 	for name, val := range s.Env {
 		g.AddProcessEnv(name, val)
 	}

pkg/specgen/specgen.go

@@ -194,6 +194,13 @@ type ContainerBasicConfig struct {
 	// The execution domain system allows Linux to provide limited support
 	// for binaries compiled under other UNIX-like operating systems.
 	Personality *spec.LinuxPersonality `json:"personality,omitempty"`
+	// UnsetEnv unsets the specified default environment variables from the image or from buildin or containers.conf
+	// Optional.
+	UnsetEnv []string `json:"unsetenv,omitempty"`
+	// UnsetEnvAll unsetall default environment variables from the image or from buildin or containers.conf
+	// UnsetEnvAll unsets all default environment variables from the image or from buildin
+	// Optional.
+	UnsetEnvAll bool `json:"unsetenvall,omitempty"`
 }
 
 // ContainerStorageConfig contains information on the storage configuration of a

pkg/specgenutil/specgen.go

@@ -711,6 +711,8 @@ func FillOutSpecGen(s *specgen.SpecGenerator, c *entities.ContainerCreateOptions
 	s.Umask = c.Umask
 	s.PidFile = c.PidFile
 	s.Volatile = c.Rm
+	s.UnsetEnv = c.UnsetEnv
+	s.UnsetEnvAll = c.UnsetEnvAll
 
 	// Initcontainers
 	s.InitContainerType = c.InitContainerType

test/system/030-run.bats

@@ -736,4 +736,26 @@ EOF
     is "$output" "$random_1" "output matches STDIN"
 }
 
+@test "podman run defaultenv" {
+    run_podman run --rm $IMAGE printenv
+    is "$output" ".*TERM=xterm" "output matches TERM"
+    is "$output" ".*container=podman" "output matches container=podman"
+
+    run_podman run --unsetenv=TERM --rm $IMAGE printenv
+    is "$output" ".*container=podman" "output matches container=podman"
+    run grep TERM <<<$output
+    is "$output" "" "unwanted TERM environment variable despite --unsetenv=TERM"
+
+    run_podman run --unsetenv-all --rm $IMAGE /bin/printenv
+    run grep TERM <<<$output
+    is "$output" "" "unwanted TERM environment variable despite --unsetenv-all"
+    run grep container <<<$output
+    is "$output" "" "unwanted container environment variable despite --unsetenv-all"
+    run grep PATH <<<$output
+    is "$output" "" "unwanted PATH environment variable despite --unsetenv-all"
+
+    run_podman run --unsetenv-all --env TERM=abc --rm $IMAGE /bin/printenv
+    is "$output" ".*TERM=abc" "missing TERM environment variable despite TERM being set on commandline"
+}
+
 # vim: filetype=sh

test/system/250-systemd.bats

@@ -174,10 +174,14 @@ function check_listen_env() {
     if is_remote; then
 	is "$output" "$stdenv" "LISTEN Environment did not pass: $context"
     else
-	is "$output" "$stdenv
+	out=$(for o in $output; do echo $o; done| sort)
+	std=$(echo "$stdenv
 LISTEN_PID=1
 LISTEN_FDS=1
-LISTEN_FDNAMES=listen_fdnames" "LISTEN Environment passed: $context"
+LISTEN_FDNAMES=listen_fdnames" | sort)
+       echo "<$out>"
+       echo "<$std>"
+       is "$out" "$std" "LISTEN Environment passed: $context"
     fi
 }