Add secrets directory credential resolver

internal/config/load_test.go

@@ -33,6 +33,29 @@ pipelines:
 	if got, want := destination.Transfer.OnDestinationOlder, TransferActionReplace; got != want {
 		t.Fatalf("transfer default = %q, want %q", got, want)
 	}
+	if cfg.Secrets.Directory != "" {
+		t.Fatalf("secrets.directory = %q, want empty", cfg.Secrets.Directory)
+	}
+}
+
+func TestLoadFileValidSecretsDirectoryConfig(t *testing.T) {
+	cfg := loadConfig(t, `
+secrets:
+  directory: /run/secrets/distributor
+pipelines:
+  - id: local-copy
+    source:
+      backend: local
+      path: /var/spool/reports
+    destinations:
+      - id: archive
+        backend: local
+        path: /srv/archive
+`)
+
+	if got, want := cfg.Secrets.Directory, "/run/secrets/distributor"; got != want {
+		t.Fatalf("secrets.directory = %q, want %q", got, want)
+	}
 }
 
 func TestLoadFileValidFanOutConfig(t *testing.T) {
@@ -351,6 +374,23 @@ pipelines:
 `, "field surprise not found")
 }
 
+func TestLoadFileRejectsUnknownSecretsFields(t *testing.T) {
+	assertLoadError(t, `
+secrets:
+  directory: /run/secrets/distributor
+  surprise: true
+pipelines:
+  - id: reports
+    source:
+      backend: local
+      path: /source
+    destinations:
+      - id: archive
+        backend: local
+        path: /archive
+`, "field surprise not found")
+}
+
 func TestExampleConfigsLoad(t *testing.T) {
 	for _, path := range []string{
 		"../../examples/local-to-local.yml",