Add generate systemd -e/--env option

-e/--env option sets environment variables to the systemd unit files.

Fixes: containers#15523

Signed-off-by: Toshiki Sonoda <sonoda.toshiki@fujitsu.com>

cmd/podman/generate/systemd.go

@@ -13,6 +13,7 @@ import (
 	"github.com/containers/podman/v4/cmd/podman/registry"
 	"github.com/containers/podman/v4/cmd/podman/utils"
 	"github.com/containers/podman/v4/pkg/domain/entities"
+	envLib "github.com/containers/podman/v4/pkg/env"
 	systemDefine "github.com/containers/podman/v4/pkg/systemd/define"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
@@ -28,9 +29,11 @@ const (
 	wantsFlagName             = "wants"
 	afterFlagName             = "after"
 	requiresFlagName          = "requires"
+	envFlagName               = "env"
 )
 
 var (
+	envInput           []string
 	files              bool
 	format             string
 	systemdRestart     string
@@ -109,6 +112,9 @@ func init() {
 	flags.StringArrayVar(&systemdOptions.Requires, requiresFlagName, nil, "Similar to wants, but declares stronger requirement dependencies")
 	_ = systemdCmd.RegisterFlagCompletionFunc(requiresFlagName, completion.AutocompleteNone)
 
+	flags.StringArrayVarP(&envInput, envFlagName, "e", []string{}, "Set environment variables to the systemd unit files")
+	_ = systemdCmd.RegisterFlagCompletionFunc(envFlagName, completion.AutocompleteNone)
+
 	flags.SetNormalizeFunc(utils.TimeoutAliasFlags)
 }
 
@@ -141,6 +147,16 @@ func systemd(cmd *cobra.Command, args []string) error {
 	if cmd.Flags().Changed(stopTimeoutCompatFlagName) {
 		setStopTimeout++
 	}
+	if cmd.Flags().Changed(envFlagName) {
+		systemdOptions.Envs = make(map[string]string)
+
+		cliEnv, err := envLib.ParseSlice(envInput)
+		if err != nil {
+			return fmt.Errorf("error parsing environment variables: %w", err)
+		}
+
+		systemdOptions.Envs = envLib.Join(systemdOptions.Envs, cliEnv)
+	}
 	switch setStopTimeout {
 	case 1:
 		systemdOptions.StopTimeout = &stopTimeout

docs/source/markdown/podman-generate-systemd.1.md

@@ -44,6 +44,14 @@ User-defined dependencies will be appended to the generated unit file, but any e
 
 Set the systemd unit name prefix for containers. The default is *container*.
 
+#### **--env**, **-e**=*env*
+
+Set environment variables to the systemd unit files.
+
+This option allows arbitrary environment variables that are available for the process to be launched inside of the container. If an environment variable is specified without a value, Podman will check the host environment for a value and set the variable only if it is set on the host. As a special case, if an environment variable ending in __*__ is specified without a value, Podman will search the host environment for variables starting with the prefix and will add those variables to the container.
+
+See [**Environment**](#environment) note below for precedence and examples.
+
 #### **--files**, **-f**
 
 Generate files instead of printing to stdout.  The generated files are named {container,pod}-{ID,name}.service and will be placed in the current working directory.

pkg/api/handlers/libpod/generate.go

@@ -17,20 +17,21 @@ func GenerateSystemd(w http.ResponseWriter, r *http.Request) {
 	runtime := r.Context().Value(api.RuntimeKey).(*libpod.Runtime)
 	decoder := r.Context().Value(api.DecoderKey).(*schema.Decoder)
 	query := struct {
-		Name             bool     `schema:"useName"`
-		New              bool     `schema:"new"`
-		NoHeader         bool     `schema:"noHeader"`
-		TemplateUnitFile bool     `schema:"templateUnitFile"`
-		RestartPolicy    *string  `schema:"restartPolicy"`
-		RestartSec       uint     `schema:"restartSec"`
-		StopTimeout      uint     `schema:"stopTimeout"`
-		StartTimeout     uint     `schema:"startTimeout"`
-		ContainerPrefix  *string  `schema:"containerPrefix"`
-		PodPrefix        *string  `schema:"podPrefix"`
-		Separator        *string  `schema:"separator"`
-		Wants            []string `schema:"wants"`
-		After            []string `schema:"after"`
-		Requires         []string `schema:"requires"`
+		Name             bool              `schema:"useName"`
+		New              bool              `schema:"new"`
+		NoHeader         bool              `schema:"noHeader"`
+		TemplateUnitFile bool              `schema:"templateUnitFile"`
+		RestartPolicy    *string           `schema:"restartPolicy"`
+		RestartSec       uint              `schema:"restartSec"`
+		StopTimeout      uint              `schema:"stopTimeout"`
+		StartTimeout     uint              `schema:"startTimeout"`
+		ContainerPrefix  *string           `schema:"containerPrefix"`
+		PodPrefix        *string           `schema:"podPrefix"`
+		Separator        *string           `schema:"separator"`
+		Wants            []string          `schema:"wants"`
+		After            []string          `schema:"after"`
+		Requires         []string          `schema:"requires"`
+		Envs             map[string]string `schema:"envs"`
 	}{
 		StartTimeout: 0,
 		StopTimeout:  util.DefaultContainerConfig().Engine.StopTimeout,
@@ -72,6 +73,7 @@ func GenerateSystemd(w http.ResponseWriter, r *http.Request) {
 		Wants:            query.Wants,
 		After:            query.After,
 		Requires:         query.Requires,
+		Envs:             query.Envs,
 	}
 
 	report, err := containerEngine.GenerateSystemd(r.Context(), utils.GetName(r), options)

pkg/bindings/generate/types.go

@@ -38,4 +38,6 @@ type SystemdOptions struct {
 	After *[]string
 	// Requires - systemd requires list for the container or pods
 	Requires *[]string
+	// Envs - environment variables setted by -e/--env
+	Envs map[string]string
 }

pkg/domain/entities/generate.go

@@ -32,6 +32,8 @@ type GenerateSystemdOptions struct {
 	After []string
 	// Requires - systemd requires list for the container or pods
 	Requires []string
+	// Envs - environment variables setted by -e/--env
+	Envs map[string]string
 }
 
 // GenerateSystemdReport

pkg/domain/infra/tunnel/generate.go

@@ -19,7 +19,8 @@ func (ic *ContainerEngine) GenerateSystemd(ctx context.Context, nameOrID string,
 		WithSeparator(opts.Separator).
 		WithWants(opts.Wants).
 		WithAfter(opts.After).
-		WithRequires(opts.Requires)
+		WithRequires(opts.Requires).
+		WithEnvs(opts.Envs)
 
 	if opts.StartTimeout != nil {
 		options.WithStartTimeout(*opts.StartTimeout)

pkg/systemd/generate/containers.go

@@ -69,6 +69,9 @@ type containerInfo struct {
 	ExtraEnvs []string
 	// EnvVariable is generate.EnvVariable and must not be set.
 	EnvVariable string
+	// OptEnvs contains the container environment variables setted by
+	// -e/--env options.
+	OptEnvs map[string]string
 	// ExecStartPre of the unit.
 	ExecStartPre string
 	// ExecStart of the unit.
@@ -127,6 +130,10 @@ Environment={{{{.EnvVariable}}}}=%n{{{{- if (eq .IdentifySpecifier true) }}}}-%i
 {{{{- if .ExtraEnvs}}}}
 Environment={{{{- range $index, $value := .ExtraEnvs -}}}}{{{{if $index}}}} {{{{end}}}}{{{{ $value }}}}{{{{end}}}}
 {{{{- end}}}}
+{{{{- if .OptEnvs}}}}
+{{{{- range $index, $value := .OptEnvs -}}}}{{{{if $index}}}}{{{{end}}}}
+Environment={{{{ $index }}}}={{{{ $value }}}}{{{{end}}}}
+{{{{- end}}}}
 Restart={{{{.RestartPolicy}}}}
 {{{{- if .StartLimitBurst}}}}
 StartLimitBurst={{{{.StartLimitBurst}}}}
@@ -321,6 +328,7 @@ func executeContainerTemplate(info *containerInfo, options entities.GenerateSyst
 
 	info.Type = "forking"
 	info.EnvVariable = define.EnvVariable
+	info.OptEnvs = options.Envs
 	info.ExecStart = "{{{{.Executable}}}} start {{{{.ContainerNameOrID}}}}"
 	info.ExecStop = "{{{{.Executable}}}} stop {{{{if (ge .StopTimeout 0)}}}}-t {{{{.StopTimeout}}}}{{{{end}}}} {{{{.ContainerNameOrID}}}}"
 	info.ExecStopPost = "{{{{.Executable}}}} stop {{{{if (ge .StopTimeout 0)}}}}-t {{{{.StopTimeout}}}}{{{{end}}}} {{{{.ContainerNameOrID}}}}"

test/e2e/generate_systemd_test.go

@@ -600,4 +600,32 @@ var _ = Describe("Podman generate systemd", func() {
 		Expect(session).Should(Exit(0))
 		Expect(session.OutputToString()).To(ContainSubstring(" --label key={{someval}}"))
 	})
+
+	It("podman generate systemd --env", func() {
+		session := podmanTest.RunTopContainer("test")
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+
+		session = podmanTest.Podman([]string{"generate", "systemd", "--env", "foo=bar", "-e", "hoge=fuga", "test"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+		Expect(session.OutputToString()).To(ContainSubstring("Environment=foo=bar"))
+		Expect(session.OutputToString()).To(ContainSubstring("Environment=hoge=fuga"))
+
+		session = podmanTest.Podman([]string{"generate", "systemd", "--env", "=bar", "-e", "hoge=fuga", "test"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(125))
+		Expect(session.ErrorToString()).To(ContainSubstring("invalid environment variable"))
+
+		session = podmanTest.Podman([]string{"generate", "systemd", "--env", "foo=bar", "-e", "hoge=fuga", "--new", "test"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+		Expect(session.OutputToString()).To(ContainSubstring("Environment=foo=bar"))
+		Expect(session.OutputToString()).To(ContainSubstring("Environment=hoge=fuga"))
+
+		session = podmanTest.Podman([]string{"generate", "systemd", "--env", "foo=bar", "-e", "=fuga", "--new", "test"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(125))
+		Expect(session.ErrorToString()).To(ContainSubstring("invalid environment variable"))
+	})
 })