diff --git a/.gitignore b/.gitignore index bb3dc13..3c841b7 100644 --- a/.gitignore +++ b/.gitignore @@ -5,7 +5,6 @@ main *.iso nimd main -boot.sh rootfs packervm test @@ -14,7 +13,5 @@ initrd* vmlinuz-linux vmlinuz* debian* -start.sh -rebuild.sh vm.qcow2 *.tar.* diff --git a/README.md b/README.md index b41147a..f7654ba 100644 --- a/README.md +++ b/README.md @@ -116,4 +116,10 @@ workers = 1 # Number of worker processes to use restartDelay = 10 # Delay (seconds) that nimd will wait before restarting itself after crashes sigtermDelay = 90 # Delay (seconds) that nimd will wait before terminating child processes with # SIGKILL after sending a more gentle SIGTERM upon shutdown or exit -``` \ No newline at end of file +``` + +## Testing NimD + +NimD is not quite ready for production yet, but in the `scripts` folder you can find a few simple bash scripts to test NimD +in a minimal Alpine Linux VM using QEMU. Note that due to weirdness in how stdout is handled on the VGA port, the VM will use +the serial port (ttyS0) as output by default (you can change this in the kernel parameters) \ No newline at end of file diff --git a/nimd.conf b/nimd.conf index 3627f6c..9d2634d 100644 --- a/nimd.conf +++ b/nimd.conf @@ -7,7 +7,7 @@ restartDelay = 10 sigtermDelay = 90 [Logging] -level = info +level = debug logFile = /var/log/nimd [Filesystem] diff --git a/scripts/boot.sh b/scripts/boot.sh new file mode 100755 index 0000000..fc9ede1 --- /dev/null +++ b/scripts/boot.sh @@ -0,0 +1,115 @@ +#!/usr/bin/env bash + +set -Eeuo pipefail +trap cleanup SIGINT SIGTERM ERR EXIT + +script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" &>/dev/null && pwd -P) + +usage() { + cat << EOF +Usage: $(basename "${BASH_SOURCE[0]}") [-h] [-v] [-m] [-b] -k kernel -i initrd -r rootfs + +Alpinemini vm + +Available options: + +-h, --help Print this help and exit +-v, --verbose Print script debug info +-k, --kernel Specify kernel file +-i, --initrd Specify initrd file +-m, --memory Set maximum vm memory +-b, --build Build a new disk (and then boot) +EOF + exit +} + +cleanup() { + trap - SIGINT SIGTERM ERR EXIT +} + +setup_colors() { + if [[ -t 2 ]] && [[ -z "${NO_COLOR-}" ]] && [[ "${TERM-}" != "dumb" ]]; then + NOFORMAT='\033[0m' RED='\033[0;31m' GREEN='\033[0;32m' ORANGE='\033[0;33m' BLUE='\033[0;34m' PURPLE='\033[0;35m' CYAN='\033[0;36m' YELLOW='\033[1;33m' + else + NOFORMAT='' RED='' GREEN='' ORANGE='' BLUE='' PURPLE='' CYAN='' YELLOW='' + fi +} + +msg() { + echo >&2 -e "${1-}" +} + +die() { + local msg=$1 + local code=${2-1} + msg "$msg" + exit "$code" +} + +parse_params() { + build=0 + rootfs='' + kernel='' + initrd='' + memory='' + + while :; do + case "${1-}" in + -h | --help) usage ;; + -v | --verbose) set -x ;; + --no-color) NO_COLOR=1 ;; + -b | --build) build=1 ;; # build disk + -k | --kernel) # kernel file + kernel="${2-}" + shift + ;; + -i | --initrd) # initrd file + initrd="${2-}" + shift + ;; + -m | --memory) # max memory + memory="${2-}" + shift + ;; + -?*) die "Unknown option: $1" ;; + *) break ;; + esac + shift + done + + args=("$@") + + # check required params and arguments + [[ -z "${kernel-}" ]] && die "${RED}Missing required parameter:${NOFORMAT} kernel" + [[ -z "${initrd-}" ]] && die "${RED}Missing required parameter:${NOFORMAT} initrd" + + return 0 +} +setup_colors +parse_params "$@" + +if ! [ -x "$(command -v qemu-system-x86_64)" ]; then + echo '${RED}Error:${NOFORMAT} unable to find qemu-system-x86_64, please install it first.' >&2 + exit 1 +fi + +if ! [ -x "$(command -v qemu-img)" ]; then + echo '${RED}Error:${NOFORMAT} unable to find qemu-img, please install it first.' >&2 + exit 1 +fi + + +if [[ $build -eq 1 ]] +then + msg "${CYAN}Building disk... Please wait${NOFORMAT}" + qemu-img create -f qcow2 vm.qcow2 800M + qemu-system-x86_64 -m 256M -smp 1 -drive file=packervm/packer.qcow2,if=virtio,readonly=on -drive file=vm.qcow2,if=virtio -enable-kvm -fsdev local,id=rootfs_dev,path=rootfs,security_model=none -device virtio-9p-pci,fsdev=rootfs_dev,mount_tag=rootfs -display none +fi + +qemumem='' +if ! [[ $memory -eq "" ]] + then + qemumem="-m ${memory}" +fi + +qemu-system-x86_64 -net nic,model=virtio,netdev=user.0 -netdev user,id=user.0 -drive file=vm.qcow2,if=virtio -enable-kvm -kernel ${kernel} -initrd ${initrd} ${qemumem} -append 'root=/dev/vda1 rw quiet modules=ext4 console=ttyS0 init=/bin/nimd' diff --git a/scripts/rebuild.sh b/scripts/rebuild.sh new file mode 100755 index 0000000..97112a3 --- /dev/null +++ b/scripts/rebuild.sh @@ -0,0 +1,10 @@ +# Build the environment +mkdir -p rootfs/etc/nimd +cp nimd.conf rootfs/etc/nimd/nimd.conf +nim -o:rootfs/bin/nimd -d:release --gc:orc --opt:size --passL:"-static" compile src/main.nim +nim -o:rootfs/bin/halt -d:release --gc:orc --opt:size --passL:"-static" compile src/programs/halt.nim +nim -o:rootfs/bin/reboot -d:release --gc:orc --opt:size --passL:"-static" compile src/programs/reboot.nim +nim -o:rootfs/bin/poweroff -d:release --gc:orc --opt:size --passL:"-static" compile src/programs/poweroff.nim + +# Start the VM +./scripts/boot.sh --kernel vmlinuz-linux --initrd initrd-linux.img --memory 1G --build diff --git a/scripts/start.sh b/scripts/start.sh new file mode 100755 index 0000000..4bb6653 --- /dev/null +++ b/scripts/start.sh @@ -0,0 +1 @@ +./scripts/boot.sh --kernel vmlinuz-linux --initrd initrd-linux.img --memory 1G diff --git a/src/core/mainloop.nim b/src/core/mainloop.nim index d79cf43..764b4f9 100644 --- a/src/core/mainloop.nim +++ b/src/core/mainloop.nim @@ -28,8 +28,8 @@ proc mainLoop*(logger: Logger, config: NimDConfig, startServices: bool = true) = if startServices: logger.info("Processing default runlevel") startServices(logger, workers=config.workers, level=Default) - logger.debug(&"Unblocking signals") - unblockSignals(logger) + logger.debug(&"Unblocking signals") + unblockSignals(logger) logger.info("System initialization complete, idling on control socket") var opType: string try: @@ -40,40 +40,49 @@ proc mainLoop*(logger: Logger, config: NimDConfig, startServices: bool = true) = logger.switchToFile() logger.debug("Entering accept() loop") while true: - serverSocket.accept(clientSocket) - logger.debug(&"Received connection on control socket") - if clientSocket.recv(opType, size=1) == 0: - logger.debug(&"Client has disconnected, waiting for new connections") - continue - logger.debug(&"Received operation type '{opType}' via control socket") - # The operation type is a single byte: - # - 'p' -> poweroff - # - 'r' -> reboot - # - 'h' -> halt - # - 's' -> Services-related operations (start, stop, get status, etc.) - # - 'l' -> Reload in-memory configuration - case opType: - of "p": - logger.info("Received shutdown request") - shutdown(logger) - of "r": - logger.info("Received reboot request") - reboot(logger) - of "h": - logger.info("Received halt request") - halt(logger) - of "s": - logger.info("Received service request") - # TODO: Operate on services - of "l": - logger.info("Received reload request") - mainLoop(logger, parseConfig(logger, "/etc/nimd/nimd.conf"), startServices=false) - else: - logger.warning(&"Received unknown operation type '{opType}' via control socket, ignoring it") - discard - clientSocket.close() + try: + serverSocket.accept(clientSocket) + logger.debug(&"Received connection on control socket") + if clientSocket.recv(opType, size=1) == 0: + logger.debug(&"Client has disconnected, waiting for new connections") + continue + logger.debug(&"Received operation type '{opType}' via control socket") + # The operation type is a single byte: + # - 'p' -> poweroff + # - 'r' -> reboot + # - 'h' -> halt + # - 's' -> Services-related operations (start, stop, get status, etc.) + # - 'l' -> Reload in-memory configuration + # - 'c' -> Check NimD status (returns "1" if up) + case opType: + of "p": + logger.info("Received shutdown request") + shutdown(logger) + of "r": + logger.info("Received reboot request") + reboot(logger) + of "h": + logger.info("Received halt request") + halt(logger) + of "s": + logger.info("Received service-related request") + # TODO: Operate on services + of "l": + logger.info("Received reload request") + mainLoop(logger, parseConfig(logger, "/etc/nimd/nimd.conf"), startServices=false) + of "c": + logger.info("Received check request, responding") + clientSocket.send("1") + else: + logger.warning(&"Received unknown operation type '{opType}' via control socket, ignoring it") + discard + except: + logger.error(&"An error occurred while idling on control socket: {getCurrentExceptionMsg()}") + finally: + clientSocket.close() + clientSocket = newSocket(AF_INET, SOCK_STREAM, IPPROTO_TCP) except: - logger.critical(&"A critical error has occurred while running, restarting the mainloop in {config.restartDelay} seconds! Error -> {getCurrentExceptionMsg()}") + logger.critical(&"A critical error has occurred while running, restarting the main loop in {config.restartDelay} seconds! Error -> {getCurrentExceptionMsg()}") sleepSeconds(config.restartDelay) # We *absolutely* cannot die mainLoop(logger, config, startServices=false) diff --git a/src/core/shutdown.nim b/src/core/shutdown.nim index b74f24d..aaf2996 100644 --- a/src/core/shutdown.nim +++ b/src/core/shutdown.nim @@ -32,16 +32,14 @@ type ShutdownHandler* = ref object const reboot_codes = {"poweroff": 0x4321fedc'i64, "reboot": 0x01234567'i64, "halt": 0xcdef0123}.toTable() +var shutdownHandlers: seq[ShutdownHandler] = @[] +var sigTermDelay: float = 90 proc newShutdownHandler*(body: proc (logger: Logger, code: int)): ShutdownHandler = result = ShutdownHandler(body: body) -var shutdownHandlers: seq[ShutdownHandler] = @[] -var sigTermDelay: float = 90 - - proc setSigTermDelay*(delay: int = 90) = # Sets the sigtermDelay variable sigTermDelay = float(delay) @@ -97,8 +95,8 @@ proc nimDExit*(logger: Logger, code: int, emerg: bool = true) = # We're in emergency mode: do not crash the kernel, spawn a shell and exit logger.fatal("NimD has entered emergency mode and cannot continue. You will be now (hopefully) dropped in a root shell: you're on your own. May the force be with you") logger.info("Terminating child processes with SIGKILL") - discard execCmd(os.getEnv("SHELL", "/bin/sh")) # TODO: Is this fine? maybe use execProcess discard posix.kill(-1, SIGKILL) + discard execCmd(os.getEnv("SHELL", "/bin/sh")) # TODO: Is this fine? maybe use execProcess quit(-1) logger.warning("The system is shutting down") logger.info("Processing shutdown runlevel") diff --git a/src/main.nim b/src/main.nim index e2e42f5..7a75fdf 100644 --- a/src/main.nim +++ b/src/main.nim @@ -14,6 +14,7 @@ import parseopt import strformat import posix +import net import os # NimD's own stuff @@ -58,9 +59,9 @@ proc addStuff = depends=(@[newDependency(Other, errorer)]), provides=(@[]), stdin="/dev/null", stderr="", stdout="") var shell = newService(name="login", description="A simple login shell", kind=Simple, - workDir=getCurrentDir(), runlevel=Boot, exec="/bin/login -f root", + workDir=getCurrentDir(), runlevel=Default, exec="/bin/login -f root", supervised=true, restart=Always, restartDelay=0, depends=(@[]), provides=(@[]), - useParentStreams=true, stdin="/dev/null", stderr="", stdout="" + useParentStreams=true, stdin="/dev/null", stderr="/proc/self/fd/2", stdout="/proc/self/fd/1" ) addService(errorer) addService(echoer) @@ -68,10 +69,55 @@ proc addStuff = addService(shell) +proc checkControlSocket(logger: Logger, config: NimDConfig): bool = + ## Performs some startup checks on nim's control + ## socket + result = true + var stat_result: Stat + if posix.stat(cstring(config.sock), stat_result) == -1 and posix.errno != 2: + logger.warning(&"Could not stat() {config.sock}, assuming NimD instance isn't running") + elif posix.errno == 2: + logger.debug(&"Control socket path is clear, starting up") + posix.errno = 0 + # 2 is ENOENT, which means the file does not exist + # I stole this from /usr/lib/python3.10/stat.py + elif (int(stat_result.st_mode) and 0o170000) != 0o140000: + logger.fatal(&"{config.sock} exists and is not a socket") + result = false + elif dirExists(config.sock): + logger.info("Control socket path is a directory, appending nimd.sock to it") + config.sock = config.sock.joinPath("nimd.sock") + else: + logger.debug("Trying to reach current NimD instance") + var sock = newSocket(Domain.AF_UNIX, SockType.SOCK_STREAM, Protocol.IPPROTO_IP) + try: + sock.connectUnix(config.sock) + logger.info("Control socket already exists, trying to reach current NimD instance") + except OSError: + logger.warning(&"Could not connect to control socket at {config.sock} ({getCurrentExceptionMsg()}), assuming NimD instance isn't running") + try: + removeFile(config.sock) + except OSError: + logger.warning(&"Could not delete dangling control socket at {config.sock} ({getCurrentExceptionMsg()})") + if sock.trySend("c"): + try: + if sock.recv(1, timeout=5) == "1": + logger.error("Another NimD instance is running! Exiting") + result = false + except OSError: + logger.warning(&"Could not read from control socket at {config.sock} ({getCurrentExceptionMsg()}), assuming NimD instance isn't running") + except TimeoutError: + logger.warning(&"Could not read from control socket at {config.sock} ({getCurrentExceptionMsg()}), assuming NimD instance isn't running") + else: + logger.fatal(&"Could not write on control socket at {config.sock}") + result = false + proc main(logger: Logger, config: NimDConfig) = ## NimD's entry point and setup ## function + if not checkControlSocket(logger, config): + return logger.debug(&"Setting log file to '{config.logFile}'") setLogFile(file=config.logFile) # Black Lives Matter. This is sarcasm btw. Fuck the left @@ -175,8 +221,7 @@ when isMainModule: quit(EINVAL) # EINVAL - Invalid argument else: echo "Usage: nimd [options]" - quit(EINVAL) # EINVAL - Invalid argument - + quit(EINVAL) # EINVAL - Invalid argument setStdIoUnbuffered() # Colors don't work otherwise! try: main(logger, parseConfig(logger, "/etc/nimd/nimd.conf"))