[#983] node: Configure subnets

Add `subnet` sub-section to `node` section of storage node config. Add
`entries` value which allows to enumerate subnets for entrance. Add
`exit_zero` value which allows to not enter zero subnet.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

config/example/node.env

@@ -16,6 +16,8 @@ NEOFS_NODE_ATTRIBUTE_0=Price:11
 NEOFS_NODE_ATTRIBUTE_1="UN-LOCODE:RU MSK"
 NEOFS_NODE_RELAY=true
 NEOFS_NODE_PERSISTENT_STATE_PATH=/state
+NEOFS_NODE_SUBNET_EXIT_ZERO=true
+NEOFS_NODE_SUBNET_ENTRIES=123 456 789
 
 # gRPC section
 NEOFS_GRPC_NUM=2

config/example/node.json

@@ -28,6 +28,14 @@
     "relay": true,
     "persistent_state": {
       "path": "/state"
+    },
+    "subnet": {
+      "exit_zero": true,
+      "entries": [
+        "123",
+        "456",
+        "789"
+      ]
     }
   },
   "grpc": {

config/example/node.yaml

@@ -25,6 +25,12 @@ node:
   relay: true  # start Storage node in relay mode without bootstrapping into the Network map
   persistent_state:  # path to persistent state file of Storage node
     path: /state
+  subnet:
+    exit_zero: true # toggle entrance to zero subnet (overrides corresponding attribute and occurrence in `entries`)
+    entries: # list of IDs of subnets to enter in a text format of NeoFS API protocol (overrides corresponding attributes)
+      - 123
+      - 456
+      - 789
 
 grpc:
   num: 2  # total number of listener endpoints