check-system

#!/usr/bin/python

import psutil
import sys

ONE_MB = 1024 ** 2

def check_bound_port(port):
    with open("/proc/net/tcp") as tcp:
        contents = tcp.read()

    # parse the contents of /proc/net/tcp looking for a bound port
    lines = contents.split('\n')

    # skip the header line
    for line in lines[1:]:
        # format is sl, local_address, rem_address, st (state), ...
        # we look for a local address whose port (in hex) matches our target
        # port and is also in the listening state (0A)
        fields = line.split()

        # ignore malformed lines
        if len(fields) < 4:
            continue

        local_address = fields[1].split(":")
        state = fields[3]
        if len(local_address) != 2:
            continue

        try:
            local_port = int(local_address[1], 16)
            if local_port == port and state == "0A":
                return True
        except ValueError:
            continue

    return False

if __name__ == "__main__":
    virtual_memory = psutil.virtual_memory()
    cpu_count = psutil.cpu_count()

    if cpu_count < 4:
        sys.stderr.write("Error: MemSQL requires at least 4 CPU cores available.\n")
        sys.stderr.write("See our documentation for help.\n")
        sys.stderr.write("http://docs.memsql.com/latest/setup/docker/\n\n")
        sys.exit(1)

    if virtual_memory.total < ONE_MB * 3700:
        sys.stderr.write("Error: MemSQL requires at least 4 GB of memory to run.\n")
        sys.stderr.write("See our documentation for help.\n")
        sys.stderr.write("http://docs.memsql.com/latest/setup/docker/\n\n")
        sys.exit(1)

    if check_bound_port(3306):
        sys.stderr.write("Error: Port 3306 is already taken.\n")
        sys.stderr.write("See our documentation for help.\n")
        sys.stderr.write("http://docs.memsql.com/latest/setup/docker/\n\n")
        sys.exit(1)

    if check_bound_port(9000):
        sys.stderr.write("Error: Port 9000 is already taken.\n")
        sys.stderr.write("See our documentation for help.\n")
        sys.stderr.write("http://docs.memsql.com/latest/setup/docker/\n\n")
        sys.exit(1)

    print("System check successful.")