refactor: move compose and deploy packages under client

pkg/client/deploy/container.go

@@ -0,0 +1,29 @@
+package deploy
+
+import (
+	"fmt"
+	"github.com/psviderski/uncloud/pkg/api"
+)
+
+type ContainerSpecStatus string
+
+const ContainerUpToDate ContainerSpecStatus = "up-to-date"
+const ContainerNeedsUpdate ContainerSpecStatus = "needs-update"
+const ContainerNeedsRecreate ContainerSpecStatus = "needs-recreate"
+
+func CompareContainerToSpec(ctr api.Container, spec api.ServiceSpec) (ContainerSpecStatus, error) {
+	specHash, err := spec.ImmutableHash()
+	if err != nil {
+		return "", fmt.Errorf("calculate immutable hash for service spec: %w", err)
+	}
+
+	// Is the hash label is unset, there is no easy way to compare its configuration with the spec,
+	// so let's recreate as well.
+	if ctr.Config.Labels[api.LabelServiceSpecHash] != specHash {
+		return ContainerNeedsRecreate, nil
+	}
+
+	// TODO: compare mutable properties such as memory or CPU limits when they are implemented.
+
+	return ContainerUpToDate, nil
+}