librbd: helper method for constructing source-spec for legacy migration

The legacy migration source format has explicit pool, namespace, and image
parameters. This helper method will convert it into the JSON format that
will be used for the new-style migration source-spec.

Signed-off-by: Jason Dillaman <dillaman@redhat.com>

diff --git a/src/librbd/migration/NativeFormat.cc b/src/librbd/migration/NativeFormat.cc
index bf6a78fc53f88ac27829c60197aa69bcdd12faba..b613f74e7ad9f97544a08dd75dbd80ce57a0d6db 100644 (file)
--- a/src/librbd/migration/NativeFormat.cc
+++ b/src/librbd/migration/NativeFormat.cc
@@ -9,6 +9,8 @@
 #include "librbd/Utils.h"
 #include "librbd/asio/ContextWQ.h"
 #include "librbd/io/ImageDispatchSpec.h"
+#include "json_spirit/json_spirit.h"
+#include <sstream>
 
 #define dout_subsys ceph_subsys_rbd
 #undef dout_prefix
@@ -18,6 +20,22 @@
 namespace librbd {
 namespace migration {
 
+template <typename I>
+std::string NativeFormat<I>::build_source_spec(
+    int64_t pool_id, const std::string& pool_namespace,
+    const std::string& image_name, const std::string& image_id) {
+  json_spirit::mObject source_spec;
+  source_spec["type"] = "native";
+  source_spec["pool_id"] = pool_id;
+  source_spec["pool_namespace"] = pool_namespace;
+  if (!image_id.empty()) {
+    source_spec["image_id"] = image_id;
+  } else {
+    source_spec["image_name"] = image_name;
+  }
+  return json_spirit::write(source_spec);
+}
+
 template <typename I>
 NativeFormat<I>::NativeFormat(
     I* image_ctx, const MigrationInfo& migration_info)

diff --git a/src/librbd/migration/NativeFormat.h b/src/librbd/migration/NativeFormat.h
index 0f0d43adc39015d8865dc2a1f84dde16b6344c95..0468be46594366821fa2e407a698b6a28d937115 100644 (file)
--- a/src/librbd/migration/NativeFormat.h
+++ b/src/librbd/migration/NativeFormat.h
@@ -21,6 +21,11 @@ namespace migration {
 template <typename ImageCtxT>
 class NativeFormat : public FormatInterface {
 public:
+  static std::string build_source_spec(int64_t pool_id,
+                                       const std::string& pool_namespace,
+                                       const std::string& image_name,
+                                       const std::string& image_id);
+
   static NativeFormat* create(ImageCtxT* image_ctx,
                               const MigrationInfo& migration_info) {
     return new NativeFormat(image_ctx, migration_info);