example of using non-juju deployed apps

prm_base.py

import os
from subprocess import call
from charms.reactive import (
    when,
    when_any,
    when_not,
    set_state,
    remove_state
)

from charmhelpers.core.host import chownr, chdir
from charmhelpers.core import unitdata

from charmhelpers.core.hookenv import (
    status_set,
    config,
    log
)

from charms.layer.prm_base import (
    PRM_DIR,
    PRM_CURRENT,
    RAILS_ENV,
    SU_CONF_DIR,
    PRM_STATIC_ASSETS,
    SHARED_STATIC_ASSETS,
    start_restart,
    render_application_yml
)


kv = unitdata.kv()


@when_not('manual.db.check')
def check_user_provided_database():
    if not config('db-uri'):
        remove_state('prm.manual.database.available')
        log("Manual database not configured")
    else:
        db_configs = {'uri': config('db-uri'),
                      'vars': "?encoding=unicode&pool=5"}
        pg_conn = ("{uri}{vars}").format(**db_configs)
        kv.set('prmdb', pg_conn)
        set_state('prm.manual.database.available')
        remove_state('prm.env.vars.available')
    set_state('manual.db.check')


@when_not('prm.postgresql.available', 'prm.manual.database.available')
def set_blocked_on_db():
    status_set('blocked', "Need database info by config or relation")


@when_not('prm.conf.dir.created')
def create_prm_conf_dir():
    """Ensure PRM config dir exists
    """
    if not os.path.isdir(SHARED_STATIC_ASSETS):
        os.makedirs(SHARED_STATIC_ASSETS, mode=0o644, exist_ok=True)
    chownr(SU_CONF_DIR, owner='www-data', group='www-data')
    set_state('prm.conf.dir.created')


@when('pgsql.connected')
@when_not('prmdb.requested')
def request_prm_database(pgsql):
    """Request prm db
    """

    status_set('maintenance', 'Requesting PostgreSQL database for PRM.')
    # Request database for PRM
    pgsql.set_database("prm_%s" % RAILS_ENV)
    pgsql.set_roles('postgres')
    # Set active status
    status_set('active', 'PostgreSQL databases requested')
    # Set state
    set_state('prmdb.requested')


@when('pgsql.master.available', 'prmdb.requested')
@when_not('prm.postgresql.available')
def get_set_prmdb_data(pgsql):
    """Get/set prmdb details
    """

    # Set maintenance status
    status_set('maintenance',
               'Getting/Setting details for PRM db.')
    # Get/set postgres master uri
    uri_vars = {'uri': pgsql.master.uri,
                'vars': "?encoding=unicode&pool=5"}
    pg_conn = "{uri}{vars}".format(**uri_vars)
    # Set pg conn info to unitdata
    kv.set('prmdb', pg_conn)
    # Set status
    status_set('active', 'Database: prm_%s available' % RAILS_ENV)
    # Set state
    set_state('prm.postgresql.available')


@when('redis.available')
@when_not('prm.redis.available')
def get_set_redis_conn(redis):
    """Get set redis connection details
    """
    status_set('maintenance', 'Setting Redis connection details.')
    db = redis.redis_data()
    db['redis_db'] = config('redis-db')
    kv.set('redis_conn', '{uri}/{redis_db}'.format(**db))
    status_set('active', 'Redis connection details saved.')
    set_state('prm.redis.available')


@when('codebase.available', 'prm.conf.dir.created')
@when_not('prm.assets.dir.available')
def symlink_static_assets():
    """Symlink static assets
    """
    if os.path.exists(PRM_STATIC_ASSETS):
        os.remove(PRM_STATIC_ASSETS)
    os.symlink(SHARED_STATIC_ASSETS, PRM_STATIC_ASSETS)
    chownr(path=os.path.dirname(os.path.normpath(PRM_DIR)),
           owner='www-data', group='www-data')
    set_state('prm.assets.dir.available')


@when('prm.redis.available', 'prm.assets.dir.available')
@when_any('prm.postgresql.available', 'prm.manual.database.available')
@when_not('prm.env.vars.available')
def write_app_yml():
    """Write out application.yml
    """
    status_set('maintenance', 'Writing application.yml')
    render_application_yml()
    status_set('active', 'Application.yml written')
    set_state('prm.env.vars.available')


@when_not('prm.ready')
@when('prm.env.vars.available', 'codebase.available')
def install_prm_deps():
    status_set('maintenance', 'Installing PRM deps')
    with chdir(PRM_CURRENT):
        call("bundle install".split())
    status_set('active', 'PRM deps installed')
    set_state('prm.ready')


@when('prm.ready')
@when_not('prm.base.available')
def set_base_avail():
    """Set prm.base.available
    """
    status_set('active', 'PRM base-layer available')
    set_state('prm.base.available')


@when('config.changed.secrets')
def rerender_application_yml():
    remove_state('prm.env.vars.available')


@when('config.changed.db-uri')
def db_config_changed():
    remove_state('manual.db.check')


@when_not('pgsql.connected')
def remove_database_available():
    remove_state('prm.postgresql.available')