Add support for environment variable secrets

Env var secrets are env vars that are set inside the container but not
commited to and image. Also support reading from env var when creating a
secret.

Signed-off-by: Ashley Cui <acui@redhat.com>

2 files changed, 85 insertions, 3 deletions

diff --git a/cmd/podman/common/specgen.go b/cmd/podman/common/specgen.go
index 310a07a00..ce7ca2b4b 100644
--- a/cmd/podman/common/specgen.go
+++ b/cmd/podman/common/specgen.go
@@ -639,11 +639,15 @@ func FillOutSpecGen(s *specgen.SpecGenerator, c *ContainerCLIOpts, args []string
 		}
 		s.RestartPolicy = splitRestart[0]
 	}
+
+	s.Secrets, s.EnvSecrets, err = parseSecrets(c.Secrets)
+	if err != nil {
+		return err
+	}
 	s.Remove = c.Rm
 	s.StopTimeout = &c.StopTimeout
 	s.Timezone = c.Timezone
 	s.Umask = c.Umask
-	s.Secrets = c.Secrets
 	s.PidFile = c.PidFile
 
 	return nil
@@ -771,3 +775,70 @@ func parseThrottleIOPsDevices(iopsDevices []string) (map[string]specs.LinuxThrot
 	}
 	return td, nil
 }
+
+func parseSecrets(secrets []string) ([]string, map[string]string, error) {
+	secretParseError := errors.New("error parsing secret")
+	var mount []string
+	envs := make(map[string]string)
+	for _, val := range secrets {
+		source := ""
+		secretType := ""
+		target := ""
+		split := strings.Split(val, ",")
+
+		// --secret mysecret
+		if len(split) == 1 {
+			source = val
+			mount = append(mount, source)
+			continue
+		}
+		// --secret mysecret,opt=opt
+		if !strings.Contains(split[0], "=") {
+			source = split[0]
+			split = split[1:]
+		}
+		// TODO: implement other secret options
+		for _, val := range split {
+			kv := strings.SplitN(val, "=", 2)
+			if len(kv) < 2 {
+				return nil, nil, errors.Wrapf(secretParseError, "option %s must be in form option=value", val)
+			}
+			switch kv[0] {
+			case "source":
+				source = kv[1]
+			case "type":
+				if secretType != "" {
+					return nil, nil, errors.Wrap(secretParseError, "cannot set more tha one secret type")
+				}
+				if kv[1] != "mount" && kv[1] != "env" {
+					return nil, nil, errors.Wrapf(secretParseError, "type %s is invalid", kv[1])
+				}
+				secretType = kv[1]
+			case "target":
+				target = kv[1]
+			default:
+				return nil, nil, errors.Wrapf(secretParseError, "option %s invalid", val)
+			}
+		}
+
+		if secretType == "" {
+			secretType = "mount"
+		}
+		if source == "" {
+			return nil, nil, errors.Wrapf(secretParseError, "no source found %s", val)
+		}
+		if secretType == "mount" {
+			if target != "" {
+				return nil, nil, errors.Wrapf(secretParseError, "target option is invalid for mounted secrets")
+			}
+			mount = append(mount, source)
+		}
+		if secretType == "env" {
+			if target == "" {
+				target = source
+			}
+			envs[target] = source
+		}
+	}
+	return mount, envs, nil
+}
diff --git a/cmd/podman/secrets/create.go b/cmd/podman/secrets/create.go
index 7374b682b..4204f30b4 100644
--- a/cmd/podman/secrets/create.go
+++ b/cmd/podman/secrets/create.go
@@ -2,15 +2,16 @@ package secrets
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"io"
 	"os"
+	"strings"
 
 	"github.com/containers/common/pkg/completion"
 	"github.com/containers/podman/v3/cmd/podman/common"
 	"github.com/containers/podman/v3/cmd/podman/registry"
 	"github.com/containers/podman/v3/pkg/domain/entities"
+	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 )
 
@@ -29,6 +30,7 @@ var (
 
 var (
 	createOpts = entities.SecretCreateOptions{}
+	env        = false
 )
 
 func init() {
@@ -43,6 +45,9 @@ func init() {
 	driverFlagName := "driver"
 	flags.StringVar(&createOpts.Driver, driverFlagName, "file", "Specify secret driver")
 	_ = createCmd.RegisterFlagCompletionFunc(driverFlagName, completion.AutocompleteNone)
+
+	envFlagName := "env"
+	flags.BoolVar(&env, envFlagName, false, "Read secret data from environment variable")
 }
 
 func create(cmd *cobra.Command, args []string) error {
@@ -52,7 +57,13 @@ func create(cmd *cobra.Command, args []string) error {
 	path := args[1]
 
 	var reader io.Reader
-	if path == "-" || path == "/dev/stdin" {
+	if env {
+		envValue := os.Getenv(path)
+		if envValue == "" {
+			return errors.Errorf("cannot create store secret data: environment variable %s is not set", path)
+		}
+		reader = strings.NewReader(envValue)
+	} else if path == "-" || path == "/dev/stdin" {
 		stat, err := os.Stdin.Stat()
 		if err != nil {
 			return err