fix: keep pull secrets and sysctls on flag deploy

internal/cmd/compute/deploy/deploy.go

@@ -163,7 +163,8 @@ template, so setting or removing one replaces the workload's instances.
 
 All of these carry forward. A deploy that does not mention a variable, an
 import, a mount, or a label keeps the one the workload already has, so a
-routine image bump changes nothing else. Remove one explicitly with a trailing
+routine image bump changes nothing else. Image pull secrets and sysctls set
+by a manifest carry forward too. Remove one explicitly with a trailing
 "-": --env KEY-, --env-from-secret NAME-, --configmap NAME-, --label key-.`,
 		Args: cobra.MaximumNArgs(1),
 		Example: `  # Deploy with flags
@@ -599,10 +600,8 @@ func deployFromFlags(cmd *cobra.Command, workloadName string, opts *options) err
 					Resources: computev1alpha.InstanceRuntimeResources{
 						InstanceType: inputs.instanceType,
 					},
-					Sandbox: &computev1alpha.SandboxRuntime{
-						Containers: []computev1alpha.SandboxContainer{container},
-					},
-					Class: runtimeClass,
+					Sandbox: sandboxRuntime(&workload, creating, container),
+					Class:   runtimeClass,
 				},
 				NetworkInterfaces: networkInterfaces,
 				Volumes:           config.volumes,
@@ -1043,6 +1042,21 @@ func resolveRuntimeClass(existing *computev1alpha.Workload, creating bool, reque
 		existing.Name, current, requested, existing.Name)
 }
 
+// sandboxRuntime returns the sandbox a flag-driven deploy writes: the one
+// container the flags describe, plus the existing workload's image pull
+// secrets and sysctls. No flag sets those, so rewriting the sandbox without
+// them would silently drop them and leave a private image unpullable.
+func sandboxRuntime(existing *computev1alpha.Workload, creating bool, container computev1alpha.SandboxContainer) *computev1alpha.SandboxRuntime {
+	sandbox := &computev1alpha.SandboxRuntime{
+		Containers: []computev1alpha.SandboxContainer{container},
+	}
+	if current := existing.Spec.Template.Spec.Runtime.Sandbox; !creating && current != nil {
+		sandbox.ImagePullSecrets = current.ImagePullSecrets
+		sandbox.Sysctls = current.Sysctls
+	}
+	return sandbox
+}
+
 // resolveNetworkInterfaces returns the network interfaces a flag-driven deploy
 // writes. A new workload gets one interface on the requested network, or on
 // "default" when none is requested.

internal/cmd/compute/deploy/sandbox_test.go

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+package deploy
+
+import (
+	"reflect"
+	"testing"
+
+	computev1alpha "go.datum.net/compute/api/v1alpha"
+)
+
+func TestSandboxRuntime(t *testing.T) {
+	secrets := []computev1alpha.LocalSecretReference{{Name: "registry-creds"}}
+	sysctls := []computev1alpha.SandboxSysctl{{Name: "net.core.somaxconn", Value: "1024"}}
+	container := computev1alpha.SandboxContainer{Name: containerName, Image: "ghcr.io/acme/api:2"}
+
+	stored := workloadWithPorts()
+	stored.Spec.Template.Spec.Runtime.Sandbox.ImagePullSecrets = secrets
+	stored.Spec.Template.Spec.Runtime.Sandbox.Sysctls = sysctls
+
+	tests := []struct {
+		name        string
+		existing    *computev1alpha.Workload
+		creating    bool
+		wantSecrets []computev1alpha.LocalSecretReference
+		wantSysctls []computev1alpha.SandboxSysctl
+	}{
+		{name: "redeploy keeps pull secrets and sysctls", existing: &stored, wantSecrets: secrets, wantSysctls: sysctls},
+		{name: "create starts empty", existing: workload(), creating: true},
+		{name: "redeploy of a workload without a sandbox", existing: workload()},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := sandboxRuntime(tt.existing, tt.creating, container)
+			if !reflect.DeepEqual(got.Containers, []computev1alpha.SandboxContainer{container}) {
+				t.Errorf("containers = %+v, want only the flag-built container", got.Containers)
+			}
+			if !reflect.DeepEqual(got.ImagePullSecrets, tt.wantSecrets) {
+				t.Errorf("imagePullSecrets = %+v, want %+v", got.ImagePullSecrets, tt.wantSecrets)
+			}
+			if !reflect.DeepEqual(got.Sysctls, tt.wantSysctls) {
+				t.Errorf("sysctls = %+v, want %+v", got.Sysctls, tt.wantSysctls)
+			}
+		})
+	}
+}