Added working implemenation

PKGBUILD

@@ -0,0 +1,11 @@
+pkgname=saturn-discover
+pkgver=1.0
+pkgrel=1
+arch=('any')
+source=('saturnDiscoverDeamon.py')
+md5sums=('SKIP')
+
+package() {
+  install -D -t "saturnDiscoverDeamon.py/usr/bin" "$srcdir/saturnDiscoverDeamon.py"
+  install -m644  $startdir/saturnDiscover.service ${pkgdir}/usr/lib/systemd/system
+}

saturnDiscover.service

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+[Unit]
+Description=SaturnArch discover Service
+After=network.target
+
+[Service]
+StandardError=journal
+StandardOutput=journal
+StandardInput=null
+Type=idle
+Restart=on-failure
+User=root
+ExecStart=/usr/bin/python /usr/bin/saturnDiscoverDeamon.py
+
+[Install]
+WantedBy=multi-user.target

saturnDiscoverDeamon.py

@@ -0,0 +1,174 @@
+import socket
+import json
+import os, sys
+from random import randint
+from time import sleep, time
+
+HOSTS    = {}
+UDP_IP   = "255.255.255.255"
+UDP_PORT = 5005
+PROT_HDR = "SATURNARCH "
+SEND_TIME = None
+
+TYPE = "slave"
+
+if os.path.exists("/etc/slurm-llnl/MASTER"):
+    TYPE = "master"
+
+MASTER = None
+
+sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
+sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
+sock.bind((UDP_IP, UDP_PORT))
+
+def nfsDone():
+    if MASTER is None:
+        return False
+
+    with open('/etc/fstab') as myfile:
+        if MASTER["ip"] in myfile.read():
+            return True
+            
+    return False
+
+def get_ip():
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    s.settimeout(0)
+    try:
+        # doesn't even have to be reachable
+        s.connect(('8.8.8.8', 1))
+        IP = s.getsockname()[0]
+    except Exception:
+        IP = '127.0.0.1'
+    finally:
+        s.close()
+    return IP
+
+def selfInfo():
+    return {
+        "ip": get_ip(),
+        "type": TYPE,
+        "name": socket.gethostname(),
+        "cpus": os.cpu_count(),
+        "rams": os.sysconf('SC_PAGE_SIZE') * os.sysconf('SC_PHYS_PAGES')
+    }
+
+
+def loadHosts():
+    global HOSTS, MASTER
+
+    try:
+        with open('/etc/slurm-llnl/hosts.json', 'r') as file:
+            HOSTS = json.load(file)
+    except:
+        HOSTS = {}
+
+    if TYPE == "master":
+        MASTER = selfInfo()
+    else:
+        for host in HOSTS.values():
+            if host["type"] == "master":
+                MASTER = host
+
+def updateHosts():
+    with open("/etc/slurm-llnl/hosts.json", "w") as outfile:
+        json.dump(HOSTS, outfile)
+
+def generateSlurmConfig(source, target):
+    if MASTER is None:
+        return
+
+    hosts = f"NodeName={socket.gethostname()} NodeAddr={get_ip()} CPUs={os.cpu_count()} State=UNKNOWN\n" # first is my self
+    noMasterHosts = ""
+    for host in HOSTS.values():
+        hosts += f"NodeName={host["name"]} NodeAddr={host["ip"]} CPUs={host["cpus"]} State=UNKNOWN\n"
+        noMasterHosts += f"{host["name"]}, "
+
+    if len(noMasterHosts) > 0:
+        noMasterHosts = noMasterHosts[:-2]
+        
+    with open(source) as f:
+        newText=f.read().replace('{%hosts%}', hosts).replace('{%noMasterHosts%}', noMasterHosts).replace('{%masterName%}', MASTER["name"]).replace('{%masterIP%}', MASTER["ip"])
+
+    with open(target, "w") as f:
+        f.write(newText)
+
+def generateHosts(target):
+    fileStr = """# Auto generated by SaturnArch
+127.0.0.1\tlocalhost
+::1\tlocalhost ip6-localhost ip6-loopback
+ff02::1\tip6-allnodes
+ff02::2\tip6-allrouters
+
+"""
+    fileStr += f"{get_ip()}\t{socket.gethostname()}\n" # first is my self
+    for host in HOSTS.values():
+        fileStr += f"{host["ip"]}\t{host["name"]}\n"
+
+    with open(target, "w") as outfile:
+        outfile.write(fileStr)
+
+def self_announcement():
+    MESSAGE = (PROT_HDR + json.dumps(selfInfo())).encode("ASCII")
+    sock.sendto(MESSAGE, (UDP_IP, UDP_PORT))
+
+## Start program
+loadHosts()
+self_announcement()
+
+while True:
+    if SEND_TIME is not None and SEND_TIME < int(time()):
+        print(f"Sending self announcement")
+        self_announcement()
+        SEND_TIME = None
+        sock.settimeout(None)
+
+    data, addr = None, None
+    try:
+        data, addr = sock.recvfrom(1024)
+        data = data.decode("ASCII")
+    except socket.timeout:
+        continue
+
+    if not data.startswith(PROT_HDR):
+        continue
+
+    data = data[len(PROT_HDR):] # remove header
+    data = json.loads(data)
+
+    if data["ip"] == get_ip():
+        continue
+
+    if data["ip"] in HOSTS and data == HOSTS[data["ip"]]:
+        continue
+
+    print(f"Discover new HOST {data}")
+
+    if data["type"] == "master":
+        MASTER = data
+
+    HOSTS[data["ip"]] = data
+    updateHosts()
+    generateHosts("/etc/hosts")
+    generateSlurmConfig("/etc/slurm-llnl/slurm.conf.template", "/etc/slurm-llnl/slurm.conf")
+    
+    # configure network disks
+    if TYPE == "slave" and MASTER is not None and not nfsDone():
+        os.system(f"echo \"{MASTER['ip']}:/clusterfs    /clusterfs    nfs    defaults   0 0\" >>  /etc/fstab")
+        os.system(f"echo \"{MASTER['ip']}:/home         /home         nfs    defaults   0 0\" >>  /etc/fstab")
+        os.system("mount -a")
+
+        os.system("cp -f /clusterfs/munge.key /etc/munge/munge.key")
+
+    # reset all services
+    os.system("systemctl restart munge")
+    os.system("systemctl restart slurmd")
+
+    if TYPE == "master":
+        os.system("systemctl restart slurmctld")
+    
+    # plan next send
+    waitTime = randint(10,100)
+    print(f"Plan self announcement at T+{waitTime}s") 
+    SEND_TIME = int(time()) + waitTime
+    sock.settimeout(waitTime / 2)