Add SSH SFTP backend support

internal/app/backends_test.go

@@ -6,6 +6,8 @@ import (
 	"testing"
 
 	"gitea.maximumdirect.net/eric/distributor/internal/config"
+	"gitea.maximumdirect.net/eric/distributor/internal/storage"
+	"gitea.maximumdirect.net/eric/distributor/internal/storage/fake"
 )
 
 func TestBackendFactoryOpensLocalSource(t *testing.T) {
@@ -47,14 +49,72 @@ func TestBackendFactoryOpensDirectLocalPath(t *testing.T) {
 	}
 }
 
+func TestBackendFactoryOpensSSHSourceWithRegisteredOpener(t *testing.T) {
+	factory := &backendFactory{registry: storage.NewRegistry()}
+	var got storage.OpenConfig
+	if err := factory.registry.Register(config.BackendSSH, func(ctx context.Context, cfg storage.OpenConfig) (storage.Backend, error) {
+		got = cfg
+		return fake.New(), nil
+	}); err != nil {
+		t.Fatalf("Register() error = %v", err)
+	}
+
+	backend, err := factory.openSource(context.Background(), config.Backend{
+		Backend: config.BackendSSH,
+		Host:    "source.example.com",
+		User:    "reports",
+		Port:    22,
+		Path:    "/reports",
+		SSH:     config.SSH{HostKeyPolicy: config.HostKeyPolicyAcceptNew},
+	})
+	if err != nil {
+		t.Fatalf("openSource() error = %v", err)
+	}
+	if backend == nil {
+		t.Fatal("openSource() backend = nil")
+	}
+	if got[sshHostKey] != "source.example.com" || got[storagePathKey] != "/reports" {
+		t.Fatalf("open config = %#v, want SSH source fields", got)
+	}
+}
+
+func TestBackendFactoryOpensSSHDestinationWithRegisteredOpener(t *testing.T) {
+	factory := &backendFactory{registry: storage.NewRegistry()}
+	var got storage.OpenConfig
+	if err := factory.registry.Register(config.BackendSSH, func(ctx context.Context, cfg storage.OpenConfig) (storage.Backend, error) {
+		got = cfg
+		return fake.New(), nil
+	}); err != nil {
+		t.Fatalf("Register() error = %v", err)
+	}
+
+	backend, err := factory.openDestination(context.Background(), config.Destination{
+		Backend: config.BackendSSH,
+		Host:    "destination.example.com",
+		User:    "deploy",
+		Port:    2222,
+		Path:    "/archive",
+		SSH:     config.SSH{HostKeyPolicy: config.HostKeyPolicyStrict},
+	})
+	if err != nil {
+		t.Fatalf("openDestination() error = %v", err)
+	}
+	if backend == nil {
+		t.Fatal("openDestination() backend = nil")
+	}
+	if got[sshHostKey] != "destination.example.com" || got[sshPortKey] != "2222" || got[sshHostKeyPolicyKey] != "strict" {
+		t.Fatalf("open config = %#v, want SSH destination fields", got)
+	}
+}
+
 func TestBackendFactoryRejectsUnsupportedSource(t *testing.T) {
 	factory := newBackendFactory()
 	_, err := factory.openSource(context.Background(), config.Backend{
-		Backend: config.BackendSSH,
-		URI:     "ssh://reports@example.com:22",
-		Path:    "/reports",
+		Backend:  config.BackendS3,
+		Endpoint: "https://s3.example.com",
+		Bucket:   "reports",
 	})
-	if err == nil || !strings.Contains(err.Error(), "source backend ssh is not implemented for execution") {
+	if err == nil || !strings.Contains(err.Error(), "source backend s3 is not implemented for execution") {
 		t.Fatalf("openSource() error = %v, want not implemented", err)
 	}
 }
@@ -70,3 +130,58 @@ func TestBackendFactoryRejectsUnsupportedDestination(t *testing.T) {
 		t.Fatalf("openDestination() error = %v, want not implemented", err)
 	}
 }
+
+func TestBackendFactoryBuildsSSHSourceOpenConfig(t *testing.T) {
+	cfg := sourceOpenConfig(config.Backend{
+		Backend: config.BackendSSH,
+		Host:    "source.example.com",
+		User:    "reports",
+		Port:    2222,
+		Path:    "/reports",
+		SSH: config.SSH{
+			KeyFile:       "/home/reports/.ssh/id_ed25519",
+			KnownHosts:    "/home/reports/.ssh/known_hosts",
+			HostKeyPolicy: config.HostKeyPolicyStrict,
+		},
+	})
+
+	assertOpenConfig(t, cfg, map[string]string{
+		storagePathKey:      "/reports",
+		sshHostKey:          "source.example.com",
+		sshUserKey:          "reports",
+		sshPortKey:          "2222",
+		sshKeyFileKey:       "/home/reports/.ssh/id_ed25519",
+		sshKnownHostsKey:    "/home/reports/.ssh/known_hosts",
+		sshHostKeyPolicyKey: "strict",
+	})
+}
+
+func TestBackendFactoryBuildsSSHDestinationOpenConfig(t *testing.T) {
+	cfg := destinationOpenConfig(config.Destination{
+		Backend: config.BackendSSH,
+		Host:    "destination.example.com",
+		User:    "deploy",
+		Port:    22,
+		Path:    "/srv/archive",
+		SSH: config.SSH{
+			HostKeyPolicy: config.HostKeyPolicyAcceptNew,
+		},
+	})
+
+	assertOpenConfig(t, cfg, map[string]string{
+		storagePathKey:      "/srv/archive",
+		sshHostKey:          "destination.example.com",
+		sshUserKey:          "deploy",
+		sshPortKey:          "22",
+		sshHostKeyPolicyKey: "accept-new",
+	})
+}
+
+func assertOpenConfig(t *testing.T, got map[string]string, want map[string]string) {
+	t.Helper()
+	for key, wantValue := range want {
+		if gotValue := got[key]; gotValue != wantValue {
+			t.Fatalf("open config %s = %q, want %q", key, gotValue, wantValue)
+		}
+	}
+}