feat: adding config and env. variable support (#379)

Co-authored-by: Eric Mastro <github@egonat.me>

README.md

@@ -29,6 +29,35 @@ Run the client with:
 ```bash
 build/codex
 ```
+## Configuration
+
+It is possible to configure a Codex node in several ways:
+ 1. CLI options
+ 2. Env. variable
+ 3. Config
+
+The order of priority is the same as above: Cli arguments > Env variables > Config file values.
+
+### Environment variables
+
+In order to set a configuration option using environment variables, first find the desired CLI option
+and then transform it in the following way:
+
+ 1. prepend it with `CODEX_`
+ 2. make it uppercase
+ 3. replace `-` with `_`
+
+For example, to configure `--log-level`, use `CODEX_LOG_LEVEL` as the environment variable name.
+
+### Configuration file
+
+A [TOML](https://toml.io/en/) configuration file can also be used to set configuration values. Configuration option names and corresponding values are placed in the file, separated by `=`. Configuration option names can be obtained from the `codex --help` command, and should not include the `--` prefix. For example, a node's log level (`--log-level`) can be configured using TOML as follows:
+
+```toml
+log-level = "TRACE"
+```
+
+The Codex node can then read the configuration from this file using the `--config-file` CLI parameter, like `codex --config-file=/path/to/your/config.toml`.
 
 ### CLI Options
 
@@ -40,6 +69,7 @@ codex [OPTIONS]... command
 
 The following options are available:
 
+     --config-file          Loads the configuration from a TOML file [=none].
      --log-level            Sets the log level [=INFO].
      --metrics              Enable the metrics server [=false].
      --metrics-address      Listening address of the metrics server [=127.0.0.1].
@@ -53,16 +83,23 @@ The following options are available:
  -b, --bootstrap-node       Specifies one or more bootstrap nodes to use when connecting to the network..
      --max-peers            The maximum number of peers to connect to [=160].
      --agent-string         Node agent string which is used as identifier in network [=Codex].
+     --api-bindaddr         The REST API bind address [=127.0.0.1].
  -p, --api-port             The REST Api port [=8080].
      --repo-kind            backend for main repo store (fs, sqlite) [=fs].
  -q, --storage-quota        The size of the total storage quota dedicated to the node [=8589934592].
- -t, --block-ttl            Default block timeout in seconds - 0 disables the ttl [=86400].
+ -t, --block-ttl            Default block timeout in seconds - 0 disables the ttl [=$DefaultBlockTtl].
+     --block-mi             Time interval in seconds - determines frequency of block maintenance cycle: how
+                            often blocks are checked for expiration and cleanup.
+                            [=$DefaultBlockMaintenanceInterval].
+     --block-mn             Number of blocks to check every maintenance cycle. [=1000].
  -c, --cache-size           The size in MiB of the block cache, 0 disables the cache - might help on slow
                             hardrives [=0].
      --persistence          Enables persistence mechanism, requires an Ethereum node [=false].
      --eth-provider         The URL of the JSON-RPC API of the Ethereum node [=ws://localhost:8545].
      --eth-account          The Ethereum account that is used for storage contracts [=EthAddress.none].
      --eth-deployment       The json file describing the contract deployment [=string.none].
+     --validator            Enables validator, requires an Ethereum node [=false].
+     --validator-max-slots  Maximum number of slots that the validator monitors [=1000].
 
 Available sub-commands:
 

codex.nim

@@ -9,7 +9,14 @@
 
 import pkg/chronicles
 import pkg/chronos
+import pkg/questionable
 import pkg/confutils
+import pkg/confutils/defs
+import pkg/confutils/std/net
+import pkg/confutils/toml/defs as confTomlDefs
+import pkg/confutils/toml/std/net as confTomlNet
+import pkg/confutils/toml/std/uri as confTomlUri
+import pkg/toml_serialization
 import pkg/libp2p
 
 import ./codex/conf
@@ -37,7 +44,11 @@ when isMainModule:
       Running
 
   let config = CodexConf.load(
-    version = codexFullVersion
+    version = codexFullVersion,
+    envVarsPrefix = "codex",
+    secondarySources = proc (config: CodexConf, sources: auto) =
+            if configFile =? config.configFile:
+              sources.addConfigFile(Toml, configFile)
   )
   config.setupLogging()
   config.setupMetrics()

codex/conf.nim

@@ -23,6 +23,7 @@ import pkg/chronicles/helpers
 import pkg/chronicles/topics_registry
 import pkg/confutils/defs
 import pkg/confutils/std/net
+import pkg/toml_serialization
 import pkg/metrics
 import pkg/metrics/chronos_httpserver
 import pkg/stew/shims/net as stewnet
@@ -51,6 +52,12 @@ type
     repoSQLite = "sqlite"
 
   CodexConf* = object
+    configFile* {.
+      desc: "Loads the configuration from a TOML file"
+      defaultValueDesc: "none"
+      defaultValue: InputFile.none
+      name: "config-file" }: Option[InputFile]
+
     logLevel* {.
       defaultValue: "INFO"
       desc: "Sets the log level",
@@ -268,7 +275,7 @@ proc defaultDataDir*(): string =
   getHomeDir() / dataDir
 
 func parseCmdArg*(T: type MultiAddress, input: string): T
-                 {.raises: [ValueError, LPError, Defect].} =
+                 {.upraises: [ValueError, LPError].} =
   MultiAddress.init($input).tryGet()
 
 proc parseCmdArg*(T: type SignedPeerRecord, uri: string): T =
@@ -285,6 +292,17 @@ proc parseCmdArg*(T: type SignedPeerRecord, uri: string): T =
 func parseCmdArg*(T: type EthAddress, address: string): T =
   EthAddress.init($address).get()
 
+proc readValue*(r: var TomlReader, val: var EthAddress)
+               {.upraises: [SerializationError, IOError].} =
+  val = EthAddress.init(r.readValue(string)).get()
+
+proc readValue*(r: var TomlReader, val: var SignedPeerRecord) =
+  without uri =? r.readValue(string).catch, err:
+    error "invalid SignedPeerRecord configuration value", error = err.msg
+    quit QuitFailure
+
+  val = SignedPeerRecord.parseCmdArg(uri)
+
 # no idea why confutils needs this:
 proc completeCmdArg*(T: type EthAddress; val: string): seq[string] =
   discard
@@ -325,7 +343,7 @@ proc stripAnsi(v: string): string =
 
   res
 
-proc updateLogLevel*(logLevel: string) {.raises: [Defect, ValueError].} =
+proc updateLogLevel*(logLevel: string) {.upraises: [ValueError].} =
   # Updates log levels (without clearing old ones)
   let directives = logLevel.split(";")
   try:

vendor/nim-confutils

@@ -1 +1 @@
-Subproject commit 0435e67832b6bb8dfdf0ddb102903e9d820206d2
+Subproject commit 2028b41602b3abf7c9bf450744efde7b296707a2

vendor/nim-stew

@@ -1 +1 @@
-Subproject commit 0c379cf1d8d3d9db07af108cc78ff542b2105914
+Subproject commit e18f5a62af2ade7a1fd1d39635d4e04d944def08

vendor/nim-toml-serialization

@@ -1 +1 @@
-Subproject commit 4e15e00ed9e27a8d28b40b69ef06c6a4a388ae93
+Subproject commit 86d477136f105f04bfd0dd7c0e939593d81fc581