fabric deployment QpV-0424_01

fabfile.py

# Template fabric deployment file for deploying Git projects

import datetime

from fabric.api import local, run, sudo, env
from fabric.colors import green, red
from fabric.context_managers import cd, lcd
from fabric.operations import put, prompt
from fabconfig import *

# Utilities

def _get_commit_id():
    "Returns the commit ID for the branch about to be deployed"
    return local('git rev-parse HEAD', capture=True)[:20]

# Deployment tasks

def deploy(branch='master', repo='origin'):
    """
    Deploys the codebase to the VM
    
    Usage:
    $ fab dev deploy            # Deploy to dev
    $ fab stage deploy          # Deploy to stage
    $ fab production deploy     # Deploy to production
    """
    update_codebase(branch, repo)
    commit_id = _get_commit_id()
    print green("Building from revision %s" % commit_id)

    archive_file = '/tmp/build-%s.tar.gz' % str(commit_id)

    prepare_build(archive_file)
    env.user = prompt('Username for remote host? [default is current user] ')
    upload(archive_file)
    unpack(archive_file, commit_id)

    _deploy_apache_config()
    _deploy_cronjobs()

    restart()

def update_codebase(branch='master', repo='origin'):
    """Updates the codebase from the Git repo"""
    print(green('Updating codebase from remote "%s", branch "%s"' % (repo, branch)))
    local('git pull %s %s' % (repo, branch))

def test():
    """Runs the tests"""
    print green('Running tests')
    with lcd(env.web_dir):
        local('./manage.py test %(test_apps) --settings=settings_test')

def prepare_build(archive_file, branch='master'):
    """Creates a gzipped tarball with the code to be deployed"""
    local('git archive --format tar %s %s | gzip > %s' % (branch, env.web_dir, archive_file))

def upload(local_path, remote_path=None):
    """Uploads a file"""
    if not remote_path:
        remote_path = local_path
    print green("Uploading %s to %s" % (local_path, remote_path))
    put(local_path, remote_path)

def unpack(archive_path, commit_id):
    """Unpacks the tarball into the correct place"""
    print green("Creating build folder") 
    now = datetime.datetime.now()
    env.build_dir = '%s-%s' % (env.build, now.strftime('%Y-%m-%d-%H-%M'))
    with cd(env.builds_dir):
        sudo('tar xzf %s' % archive_path)
        
        # Create new build folder
        sudo('if [ -d "%(build_dir)s" ]; then rm -rf "%(build_dir)s"; fi' % env)
        sudo('mv %(web_dir)s %(build_dir)s' % env)

        # Create new symlink
        sudo('if [ -h %(build)s ]; then unlink %(build)s; fi' % env)
        sudo('ln -s %(build_dir)s %(build)s' % env)

        # Add file indicating Git commit
        sudo('touch %(build)s/built-from-commit-%s' % commit_id)

        # Create a file indicating Git commit
        sudo('rm %s' % archive_path)
    
def _deploy_apache_config():
    """Deploys the apache config"""
    print green('Moving apache config into place')
    with cd(env.builds_dir):
        sudo('mv %(build)s/%(apache_conf)s /etc/apache2/sites-available/' % env)

def _deploy_cronjobs():
    """Deploys the cron jobs"""
    print green('Deploying cronjobs')
    with cd(env.builds_dir):
        sudo('if [ $(ls %(build)s/cron.d) ]; then mv %(build)s/cron.d/* /etc/cron.d/; fi' % env)

def restart():
    """Reloads python code"""
    print green('Touching WSGI file to reload python code')
    with cd(env.builds_dir):
        sudo('touch %(build)s/%(wsgi)s' % env)

def apache_reload():
    """Reloads apache config"""
    sudo('/etc/init.d/apache2 force-reload')

def apache_restart():
    """Restarts apache"""
    sudo('/etc/init.d/apache2 restart')

def nginx_reload():
    """Reloads nginx config"""
    sudo('/etc/init.d/nginx force-reload')

def nginx_restart():
    """Restarts nginx"""
    sudo('/etc/init.d/nginx restart')

def apache_configtest():
    """Checks apache config syntax"""
    sudo('/usr/sbin/apache2ctl configtest')

def nginx_configtest():
    """Checks nginx config syntax"""
    sudo('/usr/sbin/nginx -t')