84 lines
2.1 KiB
Nim
84 lines
2.1 KiB
Nim
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import docopt, json, posix, nre, strutils
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import os except sleep
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type
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CombinedConfig* = object
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docopt*: Table[string, Value]
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json*: JsonNode
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proc getVal*(cfg: CombinedConfig, key, default: string): string =
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let argKey = "--" & key
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let envKey = key.replace('-', '_').toUpper
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let jsonKey = key.replace(re"(-\w)", proc (m: RegexMatch): string = ($m)[1..1].toUpper)
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if cfg.docopt[argKey]: return $cfg.docopt[argKey]
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elif existsEnv(envKey): return getEnv(envKey)
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elif cfg.json.hasKey(jsonKey): return cfg.json[jsonKey].getStr
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else: return default
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var
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pidFileInner: string
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fi, fo, fe: File
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proc onStop(sig: cint) {.noconv.} =
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close(fi)
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close(fo)
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close(fe)
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removeFile(pidFileInner)
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quit(QuitSuccess)
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proc daemonize*(pidfile, si, so, se: string, daemonMain: proc(): void): int =
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if fileExists(pidfile):
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raise newException(IOError, "pidfile " & pidfile & " already exists, daemon already running?")
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let pid1 = fork()
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# Are we the child process?
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if pid1 == 0:
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# Yes, so let's get ready to execute the main code given to us.
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discard chdir("/")
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discard setsid()
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discard umask(0)
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# Fork again... but I'm not sure why.
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let pid2 = fork()
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# We don't need the intermediate process, so if we are not the child this
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# time, lets just quit
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if pid2 > 0: quit(QuitSuccess)
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# If we are the grandchild let's set up our environment.
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flushFile(stdout)
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flushFile(stderr)
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if not si.isNil and si != "":
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fi = open(si, fmRead)
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discard dup2(getFileHandle(fi), getFileHandle(stdin))
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if not so.isNil and so != "":
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fo = open(so, fmAppend)
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discard dup2(getFileHandle(fo), getFileHandle(stdout))
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if not se.isNil and so != "":
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fe = open(se, fmAppend)
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discard dup2(getFileHandle(fe), getFileHandle(stderr))
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pidFileInner = pidfile
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# Add hooks to cleanup after ourselves when we're asked to die.
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signal(SIGINT, onStop)
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signal(SIGTERM, onStop)
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# Find out what our actual PID is and save it
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let childPid = getpid()
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writeFile(pidfile, $childPid)
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# Finally, execute our main
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daemonMain()
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return pid1
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