ftb_minecraft_server_launcher.py

#!/usr/bin/env python3
# encoding: utf-8

"""
ftb-minecraft-server-launcher

is a small script that automates the installation of a minecraft server. It's build for Linux noobs to setup a Minecraft Server from the Feed the Beast Launcher.

What it does
============


Environment Setup
-----------------

It checks if the following programs are available:

    * zsh (one of the best Unix shells out there)
    * screen (to run the Minecraft console in background)

It will show the command to install the missing programs and exits, if something is needed.

(Optional) Downloads user configurations for zsh, screen and vim (is recommended for noobs)

http://git.grml.org/f/grml-etc-core/etc/grml/screenrc_generic       -->       ~/.screenrc
http://git.grml.org/f/grml-etc-core/etc/vim/vimrc                   -->       ~/.vimrc
http://git.grml.org/f/grml-etc-core/etc/zsh/zshrc                   -->       ~/.zshrc
http://git.grml.org/f/grml-etc-core/etc/skel/.zshrc                 -->       ~/.zshrc.local

creates a ~/.jre directory for java installations

downloads the latest java to ~/.jre

extracts java

creates a symbolic link

ln -s ~/.jre/jre_XXXX... ~/.jre/current-jre


adds java to the PATH variable


Server Setup
------------

#### Step 1. Fetches the repository server lists

http://www.creeperrepo.net/edges.json
http://ftb.cursecdn.com/edges.json

#### Modpacks.xml von einem der Repo Server laden
modpacks.xml isnt the latest version on all mirrors

third party modpacks
thirdparty.xml

 ...../FTB2/static/modpacks.xml


 #### User sucht Mod aus

 #### User sucht Version aus

 #### ServerZip laden.






"""
import os
import urllib
import urllib.request
import re
import subprocess
import json
import xml.etree.ElementTree
import zipfile
import shutil
import stat

"""
Exception wird geworfen wenn eine ungütlige destination angegeben wird.



"""
class FtbServerLauncherException(Exception): #TODO implement basic errorhandling with that exception
    def __init__(self, message):
        self.message = message




def create_dir_if_not_exists(path):
    if((os.path.exists(path) and os.path.isdir(path))==false):
        os.mkdir(path)


def dlfile(req, destination):
    # create a Request-object if given argument is a string(url)
    if isinstance(req, urllib.request.Request) == False:
        req = urllib.request.Request(req)

    if(os.path.exists(destination) and os.path.isdir(destination)):
        destination = destination + '/' + os.path.basename(req.full_url)
    if(os.path.isfile(destination)):
        print(destination + ' already downloaded')
        return destination
    print('Downloading ' + destination)
    with urllib.request.urlopen(req) as f:
        open(destination, "wb").write(f.read())
    return destination



def regex_websearch(url, pattern):
    resp = urllib.request.urlopen(url)
    content = resp.read().decode('UTF-8')
    resp.close()
    match = re.search(pattern, content)
    return match
        





def get_java_download_url(java_version=8, packag='server-jre', extension='tar.gz', architecture='linux-x64'):
    valid_packages = ['jre', 'server-jre', 'jdk']
    if package not in valid_packages:
        print('Invalid Java package selection, valid packages are:')
        for valid_package in valid_packages:
            print('\t' + valid_package)
        return None

    url = "http://www.oracle.com"

    url_1 = url + "/technetwork/java/javase/downloads/index.html"
    pattern_1 = '\/technetwork\/java/\javase\/downloads\/'+ package + str(java_version) + '-downloads-.+?\.html'
    match = regex_websearch(url_1, pattern_1)
    if match == None:
        print('Unable to download Java from ' + url_1)
        print('Website is down or script is outdated')
        return None

    url_2 = url + match.group(0)
    pattern_2 = "http\:\/\/download.oracle\.com\/otn-pub\/java\/jdk\/[7-9]u[0-9]+?-.+?\/" + package + "-[7-9]u[0-9]+?-" + architecture + "." + extension
    match = regex_websearch(url_2, pattern_2)
    if match == None:
        print('Selected architecture.extension \"' + architecture + '.' + extension + '\" is not available')
        print('Visit \"' + url_2 + '\" to see available architectures and extensions')
        return None

    
    req = urllib.request.Request(match.group(0))
    req.add_header('Cookie', 'oraclelicense=accept-securebackup-cookie')
    destination = dlfile(req, destination)

      
    return destination



"""
this function downloads the lates Java 


thx to n0ts for the idea
https://gist.github.com/n0ts/40dd9bd45578556f93e7


"""
def download_latest_java(destination, java_version=8, package='server-jre', extension='tar.gz', architecture='linux-x64'): 
    valid_packages = ['jre', 'server-jre', 'jdk']
    if package not in valid_packages:
        print('Invalid Java package selection, valid packages are:')
        for valid_package in valid_packages:
            print('\t' + valid_package)
        return None

    url = "http://www.oracle.com"

    url_1 = url + "/technetwork/java/javase/downloads/index.html"
    pattern_1 = '\/technetwork\/java/\javase\/downloads\/'+ package + str(java_version) + '-downloads-.+?\.html'
    match = regex_websearch(url_1, pattern_1)
    if match == None:
        print('Unable to download Java from ' + url_1)
        print('Website is down or script is outdated')
        return None

    url_2 = url + match.group(0)
    pattern_2 = "http\:\/\/download.oracle\.com\/otn-pub\/java\/jdk\/[7-9]u[0-9]+?-.+?\/" + package + "-[7-9]u[0-9]+?-" + architecture + "." + extension
    match = regex_websearch(url_2, pattern_2)
    if match == None:
        print('Selected architecture.extension \"' + architecture + '.' + extension + '\" is not available')
        print('Visit \"' + url_2 + '\" to see available architectures and extensions')
        return None

    
    req = urllib.request.Request(match.group(0))
    req.add_header('Cookie', 'oraclelicense=accept-securebackup-cookie')
    destination = dlfile(req, destination)

      
    return destination

def install_latest_java(destination, java_version=8, package='server-jre', extension='tar.gz', architecture='linux-x64'): 
    latest_java_tar_gz = download_latest_java(destination, java_version=java_version, package=package, extension=extension, architecture=architecture)
    print('Extracting ' + latest_java_tar_gz)
    tar_output = subprocess.check_output(['tar', 'xzvf', latest_java_tar_gz, '--directory', destination])
    new_java_dir = destination+'/'+tar_output.decode('UTF-8').split('\n')[0]
    print('Creating symlink for latest java')
    current_jre_link = destination + '/current-jre'
    if os.path.exists(current_jre_link):
        os.remove(current_jre_link)
    os.symlink(new_java_dir, current_jre_link)





def userhome_setup():
    missing_programs = []
    home_dir=os.environ['HOME']
    for program in ["zsh", "screen", "vim" ]:
        if shutil.which(program) == None:
            missing_programs.append(program)
    if(len(missing_programs)!=0):
        install_command="apt-get install "
        for program in missing_programs:
            install_command = install_command + program + ' '
        print('to install missing programs use \"'+ install_command + '\" and run this script again')
        exit(0)

    print('dowloading configurations for current user')
    #TODO remove xxxTESTxxx in release versio
    dlfile('http://git.grml.org/f/grml-etc-core/etc/grml/screenrc_generic', home_dir + '/.screenrc')
    dlfile('http://git.grml.org/f/grml-etc-core/etc/vim/vimrc', home_dir + '/.vimrcxxxTESTxxx')
    dlfile('http://git.grml.org/f/grml-etc-core/etc/zsh/zshrc', home_dir + '/.zshrc')
    dlfile('http://git.grml.org/f/grml-etc-core/etc/skel/.zshrc', home_dir + '/.zshrc.local')

    if(  (os.path.exists(home_dir+"/.jre") and os.path.isdir(home_dir+"/.jre")) == False):
        print("creating .jre directory")
        os.mkdir(home_dir + "/.jre")

    latest_java_tar_gz = install_latest_java(home_dir + '/.jre', java_version=8)

    path_update_shell_script = '\n\nif [ -d "$HOME/.jre/current-jre/bin" ] ; then\n  PATH="$HOME/.jre/current-jre/bin:$PATH"\nfi\n'
    profile_file = home_dir+'/.profile'
    if os.path.isfile(profile_file):
        print('Updating ~/.profile to include java in PATH-variable')
        f = open(profile_file, 'a')
        f.write(path_update_shell_script)
        f.close()
    zshrc_local_file = home_dir+'/.zshrc.local'
    if os.path.isfile(zshrc_local_file):
        print('Updating ~/.zshrc.local to include java in PATH-variable')
        f = open(zshrc_local_file, 'a')
        f.write(path_update_shell_script)
        f.close()
    open(home_dir+'/.ftb_minecraft_server_home_setup_finished', 'a').close()
  



def interactive_selection(message, data):
    print(message)

    i = 0
    if isinstance(data, dict):
        for key in data.keys():
            print(str(i) + ': \t' + key + '   -   ' + data.get(key))  #TODO  replace with printf (for better look and feel
            i+=1
        selection = list(data.keys())[int(input("Selection: "))] # TODO check user input
        return (selection, data.get(selection))
    if isinstance(data, list):
        for item in data:
            print(str(i) + ': \t' + item)
            i+=1
        index = int(input("Selection: ")) #TODO check user input
        return (index, data[index])


def ask_user(message, default_value, input_check_regex):
    input_str = ''
    while re.search(input_check_regex, input_str) == None:
        input_str = input(message + ' [' + default_value + ']: ')
        if input_str == '':
            input_str=default_value
            break
    return input_str

"""
returns /cat/proc/meminfo as dictionary with a ( amount, unittype ) tuple as data. If unittype is a empty string
the amount is a count

"""
def meminfo():
    meminfo_d = {}

    if(os.path.exists('/proc/meminfo')):
        with open('/proc/meminfo', 'r') as proc_meminfo:
            meminfo_content = proc_meminfo.readlines()
            for line in meminfo_content:
                match = re.search('(^[a-zA-Z0-9_\(\)]+): +(\d+) {0,1}(\w*)', line)
                meminfo_d.update({match.group(1): (int(match.group(2)), match.group(3))})
        return meminfo_d
    else:
        return None


def num_of_processing_units():
    return int(subprocess.check_output('nproc').decode('UTF-8'))

def update_server_start_sh(server_start_sh_path, xmx_value=2048, xms_value=512, java_version=8, thread_count=1):
    server_start_sh_content = open(server_start_sh_path, 'r').read()
    # shutil.move(destination_folder + '/ServerStart.sh', destination_folder + '/ServerStart.sh.bak')
    shutil.move(server_start_sh_path, server_start_sh_path + '.bak')
    match = re.search('java .+-jar ([a-zA-Z0-9_\-\.]+) (.*)$', server_start_sh_content, re.MULTILINE)
    server_start_sh_startline = match.group(0)
    server_jar=match.group(1)
    server_jar_cmd_arguments = match.group(2)
    foldername = os.path.basename(os.path.dirname(server_start_sh_path))

    if java_version==8 :
        #remove depracted options
        server_start_sh_startline = 'screen -dmS ' + foldername + ' java -Xms'+str(xms_value)+'m -Xmx'+str(xmx_value)+ \
            'm -XX:+UseG1GC -XX:+UseStringDeduplication -XX:+CMSIncrementalPacing -XX:+CMSClassUnloadingEnabled -XX:ParallelGCThreads='\
            +str(thread_count)+' -XX:MinHeapFreeRatio=5 -XX:MaxHeapFreeRatio=10 -jar '+ server_jar + ' ' + server_jar_cmd_arguments + '\n'

        server_start_sh_content = re.sub('java .+-jar ([a-zA-Z0-9_\-\.]+) (.*)$', server_start_sh_startline , server_start_sh_content, flags=re.MULTILINE)
    with open(server_start_sh_path, 'w') as f:
        f.write(server_start_sh_content)
        f.close()
    os.chmod(server_start_sh_path, stat.S_IXUSR | stat.S_IWUSR | stat.S_IRUSR) # chmod 700 


def ftb_server_install():

    # 1 Download and extract server files
    repo_servers =  json.loads(urllib.request.urlopen('http://www.creeperrepo.net/edges.json').read().decode('UTF-8'))
    repo_servers.update(json.loads(urllib.request.urlopen('http://ftb.cursecdn.com/edges.json').read().decode('UTF-8')))
    selected_repo_mirror = interactive_selection("Select the nearest server to download feed the beast modpack servers: )", repo_servers)
    # req = urllib.request.urlopen('http://' + selected_repo_mirror[1] + '/FTB2/static/modpacks.xml') # modpacks.xml isn't the latest on all mirrors!!!!!A
    modpack_xml_files = { 'FTB Modpacks': 'http://ftb.cursecdn.com/FTB2/static/modpacks.xml', '3rd Party Modpacks':'http://ftb.cursecdn.com/FTB2/static/thirdparty.xml' } # Hardcoded mirror for xml-Files
    xml_url = interactive_selection('Select Modpack Type:', modpack_xml_files)[1]
    req = urllib.request.urlopen(xml_url)
    content = req.read()
    modpacks = xml.etree.ElementTree.fromstring(content.decode('UTF-8'))
    modpack_list = []
    for modpack in modpacks:
        modpack_list.append(modpack.attrib.get('name'))
    selected_mod = interactive_selection("Select the Modpack", modpack_list)[0]
    modpack_versions = modpacks[selected_mod].get('oldVersions').split(';')
    selected_version = interactive_selection("Select the version of the mod:", modpack_versions)[1]
    download_url = 'http://' + selected_repo_mirror[1] + '/FTB2/modpacks/' + modpacks[selected_mod].get('dir') + '/' + selected_version.replace('.','_') + '/' + modpacks[selected_mod].get('serverPack')
    destination_zip_file = os.environ['HOME'] + '/' + modpacks[selected_mod].get('serverPack').replace('.zip', '_' + selected_version.replace('.','_') + '.zip')
    destination_folder = destination_zip_file.replace('.zip','')
    dlfile(download_url, destination_zip_file)
    print('Extracting "' + destination_zip_file + '" to "' + destination_folder + '"')
    with zipfile.ZipFile(destination_zip_file, 'r') as zipf:
        zipf.extractall(destination_folder)

    # 2 Configure minecraft server startscript
    print('configure ServerStart.sh - \n\tThe default values are calcualted based on your system specification')
    avail_mem = meminfo().get('MemAvailable')[0]//1024
    total_mem = meminfo().get('MemTotal')[0]//1024
    xmx_value = avail_mem-(total_mem//10) # keep 10% of total mem free
    xmx_value = int(ask_user('Java Xmx Size (Maximal Heap Space) in MiB', str(xmx_value), '\d+'))
    xms_value = xmx_value//2
    xms_value = int(ask_user('Java Xms Size (Initial Heap Space) in MiB', str(xms_value), '\d+'))
    thread_count = num_of_processing_units()
    thread_count = ask_user('Number of parallel Garbage Collector threads', str(thread_count), '[1-3]{0,1}[0-9]') # more then 30 CPUs are rare in MC Servers maybe wrong?
    print('update_server_start_sh(' + destination_folder + '/ServerStart.sh, xmx_value=' + str(xmx_value) + ', xms_value=' + str(xms_value) +', thread_count=' + str(thread_count) + ')' )

    update_server_start_sh(destination_folder + '/ServerStart.sh', xmx_value=xmx_value, xms_value=xms_value, thread_count=thread_count)



    



    


if __name__ == "__main__":
    if os.name != 'posix' :
        print(os.name + 'is not supported')
        exit(255)

    # Step 1 - setup home directory for minecraft installations.a
    if(os.path.isfile(os.environ['HOME']+'/.ftb_minecraft_server_home_setup_finished')==False):
        userhome_setup()
    ftb_server_install()