cmigrate.py

import click
import psutil
import jinja2
from glob import glob
import os
import shutil

def find_runtime():
    """Find the application runtime running on this server"""
    app_runtimes = []
    for proc in psutil.process_iter():
        if "tomcat" in proc.as_dict().values():
            app_runtimes.append("tomcat")
        elif "httpd" in proc.as_dict().values():
            app_runtimes.append("httpd")
        elif "jboss" in str(proc.as_dict().values()):
            app_runtimes.append("jboss")
    
    return list(set(app_runtimes))


def get_artefacts(app_runtime):
    """Get application related environment variable and configurations"""
    artefact = dict()

    if app_runtime == 'tomcat':
        for proc in psutil.process_iter():
            if "tomcat" in proc.as_dict().values():
                break
        artefact['APP_RUNTIME'] = app_runtime
        war_files = glob(proc.environ()['CATALINA_BASE'] + '/webapps/*.war')
        artefact['APP_DIR'] = war_files
        artefact['APP_CONFIG'] = proc.environ()['CATALINA_BASE'] + '/conf/tomcat-users.xml'
        for conn in proc.connections():
            if conn.laddr.port == 8005:
                continue
            else:
                artefact['APP_PORT'] = conn.laddr.port
        # jboss
        if app_runtime=='jboss':
            for proc in psutil.process_iter():
                if "jboss" in str(proc.as_dict().values()):
                    break
            artefact['APP_RUNTIME'] = app_runtime
            war_files = glob(proc.environ()['JBOSS_HOME'] + 'standalone/deployments/*.war')
            artefact['APP_DIR'] = war_files
            artefact['APP_CONFIG'] = proc.environ()['JBOSS_HOME'] + '/bin/standalone/configuration/standalone.xml'
            for conn in proc.connections():
                if conn.laddr.port == 8080:
                    continue
                else:
                    artefact['APP_PORT'] = conn.laddr.port

    if app_runtime == 'httpd':
        for proc in psutil.process_iter():
            if "httpd" in proc.as_dict().values():
                break
        # artefact['APP_RUNTIME'] = app_runtime
        #TODO: find config file and undertand the web dir, then copy both to artfact folder
        # html_files = glob(proc.environ()['CATALINA_BASE'] + '/webapps/*.war')
        print("Work in progress")
    return artefact

def generate_docker_file(artefacts):
    templateLoader = jinja2.FileSystemLoader(searchpath="./templates")
    templateEnv = jinja2.Environment(loader=templateLoader)
    if artefacts['APP_RUNTIME'] == "tomcat":
        TEMPLATE_FILE = "Dockerfile-tomcat.j2"
    elif artefacts['APP_RUNTIME'] == "jboss":
        TEMPLATE_FILE = "Dockerfile-jboss.j2"
    # elif artefacts['APP_RUNTIME'] == "httpd":
    #     TEMPLATE_FILE = "Dockerfile-httpd.j2"
    template = templateEnv.get_template(TEMPLATE_FILE)
    output_dir = './artefact'
    isExist = os.path.exists(output_dir)
    if not isExist:
        os.makedirs(output_dir)
    artefact_paths = []
    for artefact in artefacts['APP_DIR']:
        dst = output_dir+'/'+artefact.split('/')[-1]
        shutil.copyfile(artefact, dst)
        artefact_paths.append(dst)
    dst = output_dir+'/'+artefacts['APP_CONFIG'].split('/')[-1]
    shutil.copyfile(artefacts['APP_CONFIG'], dst)
    artefacts['APP_CONFIG'] = dst
    artefacts['APP_DIR'] = artefact_paths
    outputText = template.render(artefacts=artefacts)
    return outputText

@click.command()
@click.option('--runtime', default='empty', help='Application runtime, example: tomcat')
def build_dockerfile(runtime):
    artefacts = dict()
    app_runtime = []
    if runtime == 'empty':
        app_runtime = find_runtime()
        if len(app_runtime) == 1:
            artefacts = get_artefacts(app_runtime[0])
    else:
        artefacts = get_artefacts(runtime)
    if len(artefacts.keys()) > 0:
        print(artefacts)
        dockerfile = generate_docker_file(artefacts)
        with open('Dockerfile', 'w') as f:
            f.write(dockerfile)
        print(f"Generated Dockerfile")
    elif len(app_runtime) > 1:
        print(f'Found multiple application runtimes, pass one in --runtime parameter: {",".join(list(set(app_runtime)))}')
    else:
        print(f"Couldn't find any application running on this server")

if __name__ == '__main__':
    build_dockerfile()