Save replication settings (#415)

* Storage takes care of the saving of setting when a new replica is added

* Restore replicas at startup

* Modify interactive_mg_runner + memgraph to support that data-directory can be configured in CONTEXT

* Extend e2e test

* Correct typo

* Add flag to config to specify when replication should be stored (true by default when starting Memgraph)

* Remove un-necessary "--" in yaml file

* Make sure Memgraph stops if a replica can't be restored.

* Add UT covering the parsing  of ReplicaStatus to/from json

* Add assert in e2e script to check that a port is free before using it

* Add test covering crash on Jepsen

* Make sure applciaiton crashes if it starts on corrupted replications' info

Starting with a non-reponsive replica is allowed.

* Add temporary startup flag: this is needed so jepsen do not automatically restore replica on startup of main. This will be removed in T0835

src/memgraph.cpp

@@ -216,6 +216,11 @@ DEFINE_bool(telemetry_enabled, false,
             "the database runtime (vertex and edge counts and resource usage) "
             "to allow for easier improvement of the product.");
 
+// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
+DEFINE_bool(storage_restore_replicas_on_startup, true,
+            "Controls replicas should be restored automatically.");  // TODO(42jeremy) this must be removed once T0835
+                                                                     // is implemented.
+
 // Streams flags
 // NOLINTNEXTLINE (cppcoreguidelines-avoid-non-const-global-variables)
 DEFINE_uint32(
@@ -1195,7 +1200,8 @@ int main(int argc, char **argv) {
                      .snapshot_retention_count = FLAGS_storage_snapshot_retention_count,
                      .wal_file_size_kibibytes = FLAGS_storage_wal_file_size_kib,
                      .wal_file_flush_every_n_tx = FLAGS_storage_wal_file_flush_every_n_tx,
-                     .snapshot_on_exit = FLAGS_storage_snapshot_on_exit},
+                     .snapshot_on_exit = FLAGS_storage_snapshot_on_exit,
+                     .restore_replicas_on_startup = FLAGS_storage_restore_replicas_on_startup},
       .transaction = {.isolation_level = ParseIsolationLevel()}};
   if (FLAGS_storage_snapshot_interval_sec == 0) {
     if (FLAGS_storage_wal_enabled) {