feat(rest): Add common `rest server` utils

src/status_node_manager/rest/common.nim

@@ -0,0 +1,46 @@
+import
+  # Standard library
+  std/[typetraits],
+
+  # Nimble packages
+  chronos, confutils, presto, metrics,
+  chronicles, stew/io2,
+
+  # Project modules
+  ../config.nim
+
+func restValidate*(key: string, value: string): int =
+  0
+
+proc init*(T: type RestServerRef,
+           ip: IpAddress,
+           port: Port,
+           validateFn: PatternCallback,
+           config: StatusNodeManagerConfig): T =
+  let
+    address = initTAddress(ip, port)
+    serverFlags = {HttpServerFlags.QueryCommaSeparatedArray,
+                   HttpServerFlags.NotifyDisconnect}
+  let
+    headersTimeout =
+      if config.restRequestTimeout == 0:
+        chronos.InfiniteDuration
+      else:
+        seconds(int64(config.restRequestTimeout))
+    maxHeadersSize = config.restMaxRequestHeadersSize * 1024
+    maxRequestBodySize = config.restMaxRequestBodySize * 1024
+
+  let res = RestServerRef.new(RestRouter.init(validateFn),
+                              address, serverFlags = serverFlags,
+                              httpHeadersTimeout = headersTimeout,
+                              maxHeadersSize = maxHeadersSize,
+                              maxRequestBodySize = maxRequestBodySize,
+                              errorType = string)
+  if res.isErr():
+    notice "REST HTTP server could not be started", address = $address,
+           reason = res.error()
+    nil
+  else:
+    let server = res.get()
+    notice "Starting REST HTTP server", url = "http://" & $server.localAddress()
+    server