From bf4dbb45e5b10ea6d0c1f5ef08fd18c2cc52b7e6 Mon Sep 17 00:00:00 2001
From: Daniel Fuentes <daniel.fuentes@segment.com>
Date: Thu, 2 Aug 2018 12:24:46 -0700
Subject: [PATCH] Make secret backend configurable

---
 cmd/delete.go  |  2 +-
 cmd/exec.go    |  3 +--
 cmd/export.go  |  3 +--
 cmd/history.go |  2 +-
 cmd/import.go  |  2 +-
 cmd/list.go    |  3 +--
 cmd/read.go    |  3 ++-
 cmd/root.go    | 42 ++++++++++++++++++++++++++++++++++++++++++
 cmd/write.go   |  2 +-
 9 files changed, 51 insertions(+), 11 deletions(-)

diff --git a/cmd/delete.go b/cmd/delete.go
index bf7c00b0..eb20c80f 100644
--- a/cmd/delete.go
+++ b/cmd/delete.go
@@ -31,7 +31,7 @@ func delete(cmd *cobra.Command, args []string) error {
 		return errors.Wrap(err, "Failed to validate key")
 	}
 
-	secretStore := store.NewSSMStore(numRetries)
+	secretStore := getSecretStore()
 	secretId := store.SecretId{
 		Service: service,
 		Key:     key,
diff --git a/cmd/exec.go b/cmd/exec.go
index cb994cf1..67b8450c 100644
--- a/cmd/exec.go
+++ b/cmd/exec.go
@@ -6,7 +6,6 @@ import (
 	"strings"
 
 	"github.com/pkg/errors"
-	"github.com/segmentio/chamber/store"
 	"github.com/spf13/cobra"
 )
 
@@ -39,7 +38,7 @@ func execRun(cmd *cobra.Command, args []string) error {
 	services, command, commandArgs := args[:dashIx], args[dashIx], args[dashIx+1:]
 
 	env := environ(os.Environ())
-	secretStore := store.NewSSMStore(numRetries)
+	secretStore := getSecretStore()
 	for _, service := range services {
 		if err := validateService(service); err != nil {
 			return errors.Wrap(err, "Failed to validate service")
diff --git a/cmd/export.go b/cmd/export.go
index a54f1149..657172e8 100644
--- a/cmd/export.go
+++ b/cmd/export.go
@@ -12,7 +12,6 @@ import (
 
 	"github.com/magiconair/properties"
 	"github.com/pkg/errors"
-	"github.com/segmentio/chamber/store"
 	"github.com/spf13/cobra"
 )
 
@@ -38,7 +37,7 @@ func init() {
 func runExport(cmd *cobra.Command, args []string) error {
 	var err error
 
-	secretStore := store.NewSSMStore(numRetries)
+	secretStore := getSecretStore()
 	params := make(map[string]string)
 	for _, service := range args {
 		if err := validateService(service); err != nil {
diff --git a/cmd/history.go b/cmd/history.go
index 634fd07f..76de02d0 100644
--- a/cmd/history.go
+++ b/cmd/history.go
@@ -34,7 +34,7 @@ func history(cmd *cobra.Command, args []string) error {
 		return errors.Wrap(err, "Failed to validate key")
 	}
 
-	secretStore := store.NewSSMStore(numRetries)
+	secretStore := getSecretStore()
 	secretId := store.SecretId{
 		Service: service,
 		Key:     key,
diff --git a/cmd/import.go b/cmd/import.go
index 80471834..9ee65145 100644
--- a/cmd/import.go
+++ b/cmd/import.go
@@ -51,7 +51,7 @@ func importRun(cmd *cobra.Command, args []string) error {
 		return errors.Wrap(err, "Failed to decode input as json")
 	}
 
-	secretStore := store.NewSSMStore(numRetries)
+	secretStore := getSecretStore()
 
 	for key, value := range toBeImported {
 		secretId := store.SecretId{
diff --git a/cmd/list.go b/cmd/list.go
index 83adedc8..5b504f57 100644
--- a/cmd/list.go
+++ b/cmd/list.go
@@ -7,7 +7,6 @@ import (
 	"text/tabwriter"
 
 	"github.com/pkg/errors"
-	"github.com/segmentio/chamber/store"
 	"github.com/spf13/cobra"
 )
 
@@ -34,7 +33,7 @@ func list(cmd *cobra.Command, args []string) error {
 		return errors.Wrap(err, "Failed to validate service")
 	}
 
-	secretStore := store.NewSSMStore(numRetries)
+	secretStore := getSecretStore()
 	secrets, err := secretStore.List(service, withValues)
 	if err != nil {
 		return errors.Wrap(err, "Failed to list store contents")
diff --git a/cmd/read.go b/cmd/read.go
index d403479a..d18d6b1f 100644
--- a/cmd/read.go
+++ b/cmd/read.go
@@ -41,7 +41,8 @@ func read(cmd *cobra.Command, args []string) error {
 		return errors.Wrap(err, "Failed to validate key")
 	}
 
-	secretStore := store.NewSSMStore(numRetries)
+	secretStore := getSecretStore()
+
 	secretId := store.SecretId{
 		Service: service,
 		Key:     key,
diff --git a/cmd/root.go b/cmd/root.go
index ef689c80..b75e1256 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -6,6 +6,7 @@ import (
 	"regexp"
 	"strings"
 
+	"github.com/segmentio/chamber/store"
 	"github.com/spf13/cobra"
 )
 
@@ -26,6 +27,15 @@ const (
 	DefaultNumRetries = 10
 )
 
+const (
+	SSMBackend = "SSM"
+	S3Backend  = "S3"
+
+	BackendEnvVar = "CHAMBER_SECRET_BACKEND"
+)
+
+var Backends = []string{SSMBackend, S3Backend}
+
 // RootCmd represents the base command when called without any subcommands
 var RootCmd = &cobra.Command{
 	Use:          "chamber",
@@ -62,3 +72,35 @@ func validateKey(key string) error {
 	}
 	return nil
 }
+
+func getSecretStore() store.Store {
+	backend, ok := os.LookupEnv(BackendEnvVar)
+	if !ok {
+		backend = SSMBackend
+	}
+
+	backend = strings.ToUpper(backend)
+	if !stringInSlice(backend, Backends) {
+		// TODO: warn user
+		backend = SSMBackend
+	}
+
+	switch backend {
+	case SSMBackend:
+		return store.NewSSMStore(numRetries)
+	case S3Backend:
+		return store.NewS3Store(numRetries)
+	}
+
+	// This line is unreachable, but necessary to satisfy the compiler
+	panic("unreachable")
+}
+
+func stringInSlice(v string, sl []string) bool {
+	for _, val := range sl {
+		if v == val {
+			return true
+		}
+	}
+	return false
+}
diff --git a/cmd/write.go b/cmd/write.go
index 50a58fe0..de7d4de0 100644
--- a/cmd/write.go
+++ b/cmd/write.go
@@ -58,7 +58,7 @@ func write(cmd *cobra.Command, args []string) error {
 		}
 	}
 
-	secretStore := store.NewSSMStore(numRetries)
+	secretStore := getSecretStore()
 	secretId := store.SecretId{
 		Service: service,
 		Key:     key,