initial add keeper az info in /keeper/availabilty-zone

Signed-off-by: Jianfei Hu <hujianfei258@gmail.com>

src/Coordination/KeeperContext.cpp

@@ -9,6 +9,13 @@
 #include <Coordination/KeeperFeatureFlags.h>
 #include <boost/algorithm/string.hpp>
 
+#if USE_AWS_S3
+
+#include <IO/S3/Credentials.h>
+#include <aws/core/auth/AWSCredentials.h>
+#include <aws/core/client/ClientConfiguration.h>
+#endif
+
 namespace DB
 {
 
@@ -30,6 +37,11 @@ KeeperContext::KeeperContext(bool standalone_keeper_)
 
     /// for older clients, the default is equivalent to WITH_MULTI_READ version
     system_nodes_with_data[keeper_api_version_path] = toString(static_cast<uint8_t>(KeeperApiVersion::WITH_MULTI_READ));
+
+    #if USE_AWS_S3
+    auto metadata_client = S3::InitEC2MetadataClient(Aws::Client::ClientConfiguration{});
+    running_availability_zone = metadata_client->getCurrentAvailabilityZone();
+    #endif
 }
 
 void KeeperContext::initialize(const Poco::Util::AbstractConfiguration & config, KeeperDispatcher * dispatcher_)
@@ -204,6 +216,11 @@ void KeeperContext::setStateFileDisk(DiskPtr disk)
     state_file_storage = std::move(disk);
 }
 
+std::string KeeperContext::getRunningAvailabilityZone() const
+{
+    return running_availability_zone;
+}
+
 const std::unordered_map<std::string, std::string> & KeeperContext::getSystemNodesWithData() const
 {
     return system_nodes_with_data;

src/Coordination/KeeperContext.h

@@ -3,7 +3,6 @@
 #include <Disks/DiskSelector.h>
 #include <IO/WriteBufferFromString.h>
 #include <Poco/Util/AbstractConfiguration.h>
-
 #include <cstdint>
 #include <memory>
 
@@ -54,6 +53,8 @@ public:
 
     constexpr KeeperDispatcher * getDispatcher() const { return dispatcher; }
 
+    std::string getRunningAvailabilityZone() const;
+
 private:
     /// local disk defined using path or disk name
     using Storage = std::variant<DiskPtr, std::string>;
@@ -89,6 +90,8 @@ private:
 
     KeeperFeatureFlags feature_flags;
     KeeperDispatcher * dispatcher{nullptr};
+
+    std::string running_availability_zone;
 };
 
 using KeeperContextPtr = std::shared_ptr<KeeperContext>;

src/Coordination/KeeperStorage.cpp

@@ -1097,6 +1097,14 @@ struct KeeperStorageGetRequestProcessor final : public KeeperStorageRequestProce
         Coordination::ZooKeeperGetResponse & response = dynamic_cast<Coordination::ZooKeeperGetResponse &>(*response_ptr);
         Coordination::ZooKeeperGetRequest & request = dynamic_cast<Coordination::ZooKeeperGetRequest &>(*zk_request);
 
+        /// AZ node information is a special case not persisted in the storage, so we handle it first.
+        if (request.path == "/keeper/availbility-zone")
+        {
+            response.data = storage.keeper_context->getRunningAvailabilityZone();
+            response.error = Coordination::Error::ZOK;
+            return response_ptr;
+        }
+
         if constexpr (!local)
         {
             if (const auto result = storage.commit(zxid); result != Coordination::Error::ZOK)

src/IO/S3/Credentials.cpp

@@ -704,6 +704,7 @@ S3CredentialsProviderChain::S3CredentialsProviderChain(
 
             aws_client_configuration.retryStrategy = std::make_shared<Aws::Client::DefaultRetryStrategy>(1, 1000);
 
+            // Code that we want to copy.
             auto ec2_metadata_client = InitEC2MetadataClient(aws_client_configuration);
             auto config_loader = std::make_shared<AWSEC2InstanceProfileConfigLoader>(ec2_metadata_client, !credentials_configuration.use_insecure_imds_request);