Propper logging options (#81)

config.nims

@@ -66,4 +66,4 @@ switch("warning", "ObservableStores:off")
 
 # Too many false positives for "Warning: method has lock level <unknown>, but another method has 0 [LockLevel]"
 switch("warning", "LockLevel:off")
-
+switch("define", "chronicles_sinks=textlines[dynamic],json[dynamic]")

dagger.nim

@@ -27,8 +27,8 @@ when isMainModule:
   when defined(posix):
     import system/ansi_c
 
-  let
-    config = DaggerConf.load()
+  let config = DaggerConf.load()
+  config.setupLogging()
 
   case config.cmd:
   of StartUpCommand.noCommand:

dagger/conf.nim

@@ -12,9 +12,12 @@ import pkg/upraises
 push: {.upraises: [].}
 
 import std/os
+import std/terminal
 import std/options
+import std/typetraits
 
 import pkg/chronicles
+import pkg/chronicles/topics_registry
 import pkg/confutils/defs
 import pkg/libp2p
 
@@ -30,10 +33,26 @@ type
     noCommand,
     initNode
 
+  LogKind* = enum
+    Auto = "auto"
+    Colors = "colors"
+    NoColors = "nocolors"
+    Json = "json"
+    None = "none"
+
   DaggerConf* = object
     logLevel* {.
       defaultValue: LogLevel.INFO
-      desc: "Sets the log level" }: LogLevel
+      desc: "Sets the log level",
+      name: "log-level" }: LogLevel
+
+    logFormat* {.
+      hidden
+      desc: "Specifies what kind of logs should be written to stdout (auto, colors, nocolors, json)"
+      defaultValueDesc: "auto"
+      defaultValue: LogKind.Auto
+      name: "log-format" }: LogKind
+
 
     dataDir* {.
       desc: "The directory where dagger will store configuration and data."
@@ -99,3 +118,76 @@ proc defaultDataDir*(): string =
 func parseCmdArg*(T: type MultiAddress, input: TaintedString): T
                  {.raises: [ValueError, LPError, Defect].} =
   MultiAddress.init($input).tryGet()
+
+# silly chronicles, colors is a compile-time property
+proc stripAnsi(v: string): string =
+  var
+    res = newStringOfCap(v.len)
+    i: int
+
+  while i < v.len:
+    let c = v[i]
+    if c == '\x1b':
+      var
+        x = i + 1
+        found = false
+
+      while x < v.len: # look for [..m
+        let c2 = v[x]
+        if x == i + 1:
+          if c2 != '[':
+            break
+        else:
+          if c2 in {'0'..'9'} + {';'}:
+            discard # keep looking
+          elif c2 == 'm':
+            i = x + 1
+            found = true
+            break
+          else:
+            break
+        inc x
+
+      if found: # skip adding c
+        continue
+    res.add c
+    inc i
+
+  res
+
+proc setupLogging*(conf: DaggerConf) =
+  when defaultChroniclesStream.outputs.type.arity != 2:
+    warn "Logging configuration options not enabled in the current build"
+  else:
+    proc noOutput(logLevel: LogLevel, msg: LogOutputStr) = discard
+    proc writeAndFlush(f: File, msg: LogOutputStr) =
+      try:
+        f.write(msg)
+        f.flushFile()
+      except IOError as err:
+        logLoggingFailure(cstring(msg), err)
+
+    proc stdoutFlush(logLevel: LogLevel, msg: LogOutputStr) =
+      writeAndFlush(stdout, msg)
+
+    proc noColorsFlush(logLevel: LogLevel, msg: LogOutputStr) =
+      writeAndFlush(stdout, stripAnsi(msg))
+
+    defaultChroniclesStream.outputs[1].writer = noOutput
+
+    defaultChroniclesStream.outputs[0].writer =
+      case conf.logFormat:
+      of LogKind.Auto:
+        if isatty(stdout):
+          stdoutFlush
+        else:
+          noColorsFlush
+      of LogKind.Colors: stdoutFlush
+      of LogKind.NoColors: noColorsFlush
+      of LogKind.Json:
+        defaultChroniclesStream.outputs[1].writer = stdoutFlush
+        noOutput
+      of LogKind.None:
+        noOutput
+
+    setLogLevel(conf.logLevel)