Move /cli/command/stack/kubernetes/api to /kubernetes

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

kubernetes/labels/labels.go

@@ -0,0 +1,58 @@
+package labels
+
+import (
+	"fmt"
+	"strings"
+)
+
+const (
+	// ForServiceName is the label for the service name.
+	ForServiceName = "com.docker.service.name"
+	// ForStackName is the label for the stack name.
+	ForStackName = "com.docker.stack.namespace"
+	// ForServiceID is the label for the service id.
+	ForServiceID = "com.docker.service.id"
+)
+
+// ForService gives the labels to select a given service in a stack.
+func ForService(stackName, serviceName string) map[string]string {
+	labels := map[string]string{}
+
+	if serviceName != "" {
+		labels[ForServiceName] = serviceName
+	}
+	if stackName != "" {
+		labels[ForStackName] = stackName
+	}
+	if serviceName != "" && stackName != "" {
+		labels[ForServiceID] = stackName + "-" + serviceName
+	}
+
+	return labels
+}
+
+// Merge merges multiple lists of labels.
+func Merge(labelsList ...map[string]string) map[string]string {
+	merged := map[string]string{}
+
+	for _, labels := range labelsList {
+		for k, v := range labels {
+			merged[k] = v
+		}
+	}
+
+	return merged
+}
+
+// SelectorForStack gives the labelSelector to use for a given stack.
+// Specific service names can be passed to narrow down the selection.
+func SelectorForStack(stackName string, serviceNames ...string) string {
+	switch len(serviceNames) {
+	case 0:
+		return fmt.Sprintf("%s=%s", ForStackName, stackName)
+	case 1:
+		return fmt.Sprintf("%s=%s,%s=%s", ForStackName, stackName, ForServiceName, serviceNames[0])
+	default:
+		return fmt.Sprintf("%s=%s,%s in (%s)", ForStackName, stackName, ForServiceName, strings.Join(serviceNames, ","))
+	}
+}