api: storage_service: remove_node: validate host_id

The node to be removed must be identified by its host_id.
Validate that at the api layer and pass the parsed host_id
down to storage_service::removenode.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>

locator/token_metadata.cc

@@ -1432,4 +1432,33 @@ future<> shared_token_metadata::mutate_token_metadata(seastar::noncopyable_funct
     set(make_token_metadata_ptr(std::move(tm)));
 }
 
+host_id_or_endpoint::host_id_or_endpoint(const sstring& s, param_type restrict) {
+    switch (restrict) {
+    case param_type::host_id:
+        try {
+            id = host_id(utils::UUID(s));
+        } catch (const marshal_exception& e) {
+            throw std::invalid_argument(format("Invalid host_id {}: {}", s, e.what()));
+        }
+        break;
+    case param_type::endpoint:
+        try {
+            endpoint = gms::inet_address(s);
+        } catch (std::invalid_argument& e) {
+            throw std::invalid_argument(format("Invalid inet_address {}: {}", s, e.what()));
+        }
+        break;
+    case param_type::auto_detect:
+        try {
+            id = host_id(utils::UUID(s));
+        } catch (const marshal_exception& e) {
+            try {
+                endpoint = gms::inet_address(s);
+            } catch (std::invalid_argument& e) {
+                throw std::invalid_argument(format("Invalid host_id or inet_address {}", s));
+            }
+        }
+    }
+}
+
 } // namespace locator

locator/token_metadata.hh

@@ -133,6 +133,27 @@ private:
     bool _sort_by_proximity = true;
 };
 
+struct host_id_or_endpoint {
+    host_id id;
+    gms::inet_address endpoint;
+
+    enum class param_type {
+        host_id,
+        endpoint,
+        auto_detect
+    };
+
+    host_id_or_endpoint(const sstring& s, param_type restrict = param_type::auto_detect);
+
+    bool has_host_id() const noexcept {
+        return bool(id);
+    }
+
+    bool has_endpoint() const noexcept {
+        return endpoint != gms::inet_address();
+    }
+};
+
 using dc_rack_fn = seastar::noncopyable_function<endpoint_dc_rack(inet_address)>;
 class token_metadata_impl;