Add configurable workspace prefix for S3 Backend

backend/remote-state/s3/backend.go

@@ -139,6 +139,13 @@ func New() backend.Backend {
 				Description: "The permissions applied when assuming a role.",
 				Default:     "",
 			},
+
+			"workspace_key_prefix": {
+				Type:        schema.TypeString,
+				Optional:    true,
+				Description: "The prefix applied to the state path inside the bucket",
+				Default:     "env:",
+			},
 		},
 	}
 
@@ -160,6 +167,7 @@ type Backend struct {
 	acl                  string
 	kmsKeyID             string
 	ddbTable             string
+	workspaceKeyPrefix   string
 }
 
 func (b *Backend) configure(ctx context.Context) error {
@@ -175,6 +183,7 @@ func (b *Backend) configure(ctx context.Context) error {
 	b.serverSideEncryption = data.Get("encrypt").(bool)
 	b.acl = data.Get("acl").(string)
 	b.kmsKeyID = data.Get("kms_key_id").(string)
+	b.workspaceKeyPrefix = data.Get("workspace_key_prefix").(string)
 
 	b.ddbTable = data.Get("dynamodb_table").(string)
 	if b.ddbTable == "" {

backend/remote-state/s3/backend_state.go

@@ -14,16 +14,10 @@ import (
 	"github.com/hashicorp/terraform/terraform"
 )
 
-const (
-	// This will be used as directory name, the odd looking colon is simply to
-	// reduce the chance of name conflicts with existing objects.
-	keyEnvPrefix = "env:"
-)
-
 func (b *Backend) States() ([]string, error) {
 	params := &s3.ListObjectsInput{
 		Bucket: &b.bucketName,
-		Prefix: aws.String(keyEnvPrefix + "/"),
+		Prefix: aws.String(b.workspaceKeyPrefix + "/"),
 	}
 
 	resp, err := b.s3Client.ListObjects(params)
@@ -53,7 +47,7 @@ func (b *Backend) keyEnv(key string) string {
 	}
 
 	// shouldn't happen since we listed by prefix
-	if parts[0] != keyEnvPrefix {
+	if parts[0] != b.workspaceKeyPrefix {
 		return ""
 	}
 
@@ -179,7 +173,7 @@ func (b *Backend) path(name string) string {
 		return b.keyName
 	}
 
-	return strings.Join([]string{keyEnvPrefix, name, b.keyName}, "/")
+	return strings.Join([]string{b.workspaceKeyPrefix, name, b.keyName}, "/")
 }
 
 const errStateUnlock = `

backend/remote-state/s3/backend_test.go

@@ -159,7 +159,7 @@ func TestBackendExtraPaths(t *testing.T) {
 	}
 
 	// put a state in an env directory name
-	client.path = keyEnvPrefix + "/error"
+	client.path = b.workspaceKeyPrefix + "/error"
 	stateMgr.WriteState(terraform.NewState())
 	if err := stateMgr.PersistState(); err != nil {
 		t.Fatal(err)
@@ -169,7 +169,7 @@ func TestBackendExtraPaths(t *testing.T) {
 	}
 
 	// add state with the wrong key for an existing env
-	client.path = keyEnvPrefix + "/s2/notTestState"
+	client.path = b.workspaceKeyPrefix + "/s2/notTestState"
 	stateMgr.WriteState(terraform.NewState())
 	if err := stateMgr.PersistState(); err != nil {
 		t.Fatal(err)
@@ -202,7 +202,7 @@ func TestBackendExtraPaths(t *testing.T) {
 	s2 = s2Mgr.State()
 
 	// add a state with a key that matches an existing environment dir name
-	client.path = keyEnvPrefix + "/s2/"
+	client.path = b.workspaceKeyPrefix + "/s2/"
 	stateMgr.WriteState(terraform.NewState())
 	if err := stateMgr.PersistState(); err != nil {
 		t.Fatal(err)

website/docs/backends/types/s3.html.md

@@ -108,3 +108,6 @@ The following configuration options or environment variables are supported:
  * `assume_role_policy` - (Optional) The permissions applied when assuming a role.
  * `external_id` - (Optional) The external ID to use when assuming the role.
  * `session_name` - (Optional) The session name to use when assuming the role.
+ * `workspace_key_prefix` - (Optional) The prefix applied to the state path 
+   inside the bucket. This is only relevant when using a non-default workspace.
+   This defaults to "env:"