feat(config): add config file support (#953)

including

* bump vendor/nim-confutils
* add nim-toml-serialization submodule
* feat(config): add example config file
* add new feature to CHANGELOG

.gitmodules

@@ -140,3 +140,6 @@
 	url = https://github.com/ba0f3/dnsclient.nim.git
 	ignore = untracked
 	branch = master
+[submodule "vendor/nim-toml-serialization"]
+	path = vendor/nim-toml-serialization
+	url = https://github.com/status-im/nim-toml-serialization.git

CHANGELOG.md

@@ -12,6 +12,7 @@ The full list of changes is below.
 
 - Support for bootstrapping [`33/WAKU-DISCV5`](https://rfc.vac.dev/spec/33) via [DNS discovery](https://rfc.vac.dev/spec/10/#discovery-methods)
 - Support for GossipSub [Peer Exchange](https://github.com/libp2p/specs/blob/master/pubsub/gossipsub/gossipsub-v1.1.md#prune-backoff-and-peer-exchange)
+- Support for TOML config files via `--config-file=<path/to/config.toml>`
 
 
 ### Changes

examples/v2/example_config.toml

@@ -0,0 +1,11 @@
+relay=true
+store=true
+filter=true
+db-path="./dbs/db1"
+rpc-admin=true
+persist-peers=true
+keep-alive=true
+persist-messages=true
+lightpush=true
+nodekey="f157b19b13e9ee818acfc9d3d7eec6b81f70c0a978dec19def261172acbe26e6"
+ports-shift=1

vendor/nim-confutils

@@ -1 +1 @@
-Subproject commit 05a438414a91ae6729c6f1966358909840368e0c
+Subproject commit d06f6187dca702ad884b9b948f52b26bf6596765

vendor/nim-toml-serialization

@@ -0,0 +1 @@
+Subproject commit 90369dd67b4a41109e26716829f6f3f077eddf38

waku/v2/node/config.nim

@@ -1,6 +1,8 @@
 import
   std/strutils,
   confutils, confutils/defs, confutils/std/net,
+  confutils/toml/defs as confTomlDefs,
+  confutils/toml/std/net as confTomlNet,
   chronicles, chronos,
   libp2p/crypto/crypto,
   libp2p/crypto/secp,
@@ -9,10 +11,18 @@ import
   ../protocol/waku_rln_relay/waku_rln_relay_types,
   ../protocol/waku_message
 
+export
+  confTomlDefs,
+  confTomlNet
+   
 type
   WakuNodeConf* = object
     ## General node config
 
+    configFile* {.
+      desc: "Loads configuration from a TOML file (cmd-line parameters take precedence)"
+      name: "config-file" }: Option[InputFile]
+
     logLevel* {.
       desc: "Sets the log level."
       defaultValue: LogLevel.INFO
@@ -348,3 +358,11 @@ func defaultListenAddress*(conf: WakuNodeConf): ValidIpAddress =
   # TODO: How should we select between IPv4 and IPv6
   # Maybe there should be a config option for this.
   (static ValidIpAddress.init("0.0.0.0"))
+
+
+proc readValue*(r: var TomlReader, val: var crypto.PrivateKey)
+               {.raises: [Defect, IOError, SerializationError].} =
+  val = try: parseCmdArg(crypto.PrivateKey, r.readValue(string))
+        except CatchableError as err:
+          raise newException(SerializationError, err.msg)
+

waku/v2/node/wakunode2.nim

@@ -972,7 +972,7 @@ when isMainModule:
   ## 6. Setup graceful shutdown hooks
 
   import
-    confutils,
+    confutils, toml_serialization,
     system/ansi_c,
     libp2p/nameresolving/dnsresolver,
     ../../common/utils/nat,
@@ -1294,8 +1294,17 @@ when isMainModule:
     
     ok(true) # Success
 
-  let
+  {.push warning[ProveInit]: off.}
-    conf = WakuNodeConf.load()
+  let conf = try:
+    WakuNodeConf.load(
+      secondarySources = proc (conf: WakuNodeConf, sources: auto) =
+        if conf.configFile.isSome:
+          sources.addConfigFile(Toml, conf.configFile.get)
+    )
+  except CatchableError as err:
+    error "Failure while loading the configuration: \n", err_msg=err.msg
+    quit 1 # if we don't leave here, the initialization of conf does not work in the success case
+  {.pop.}
 
   var
     node: WakuNode  # This is the node we're going to setup using the conf