Basic executors¶
Mirakuru’s Executor
is something that You’ll use, when you’ll
need to make some code dependant from other process being run, and in certain state,
and you wouldn’t want this process to be running all the time.
Tests would be best example here, or a script that sets up processes and databases for dev environment with one simple run.
Executor¶
mirakuru.base.Executor
is the simplest executor implementation.
It simply starts the process passed to constructor, and reports it as running.
from mirakuru import Executor
process = Executor('my_special_process')
process.start()
# Do your stuff
process.stop()
OutputExecutor¶
mirakuru.output.OutputExecutor
is the executor that starts the process,
but does not report it as started, unless it receives specified marker/banner in
process output.
from mirakuru import OutputExecutor
process = OutputExecutor('my_special_process', banner='processed!')
process.start()
# Do your stuff
process.stop()
What happens during start here, is that the executor constantly checks output produced by started process, and looks for the banner part occurring within the output. Once the output is identified, like in example processed! is found in output. It’s considered as started, and executor releases your script from wait to work.
TCPExecutor¶
mirakuru.tcp.TCPExecutor
is the executor that should be used to start
processes that are using TCP connection. This executor tries to connect with
process on given host:port to see if it started accepting connections. Once it
does, it reports the process as started and code returns to normal execution.
from mirakuru import TCPExecutor
process = TCPExecutor('my_special_process', host='localhost', port=1234)
process.start()
# Do your stuff
process.stop()
HTTPExecutor¶
mirakuru.http.HTTPExecutor
is executor that will be used to start
web apps for example. To start it, you apart from command, you need to pass an url.
This url will be used to make a HEAD request to. Once successful,
executor will be considered started, and code will return to normal execution.
from mirakuru import HTTPExecutor
process = HTTPExecutor('my_special_process', url='http://localhost:6543/status')
process.start()
# Do your stuff
process.stop()
This executor however, apart from HEAD request, also inherits TCPExecutor, so it’ll try to connect to process over TCP first, to determine, if it can try to make a HEAD request already.
PidExecutor¶
mirakuru.pid.PidExecutor
is an executor that starts the given
process, then waits for a given file to be found before it gives back control.
An example use for this class is writing integration tests for processes that
notify their running by creating a .pid file.
from mirakuru import PidExecutor
process = PidExecutor('my_special_process', filename='/bla/ble/my_special_process.pid')
process.start()
# Do your stuff
process.stop()
As a Context manager¶
Starting¶
Mirakuru’s executors can also work as a context managers.
from mirakuru import HTTPExecutor
process = HTTPExecutor('my_special_process', url='http://localhost:6543/status')
with process:
# Do your stuff
assert process.running() is True
assert process.running() is False
Defined process starts upon entering context, and exit upon exiting it.
Stopping¶
Mirakuru also allows to stop process for given context. To do this, simply use built-in stopped context manager.
from mirakuru import HTTPExecutor
process = HTTPExecutor('my_special_process', url='http://localhost:6543/status')
process.start()
# do some stuff
with process.stopped():
# Do something hidden
assert process.running() is False
assert process.running() is True
Defined process stops upon entering context, and starts upon exiting it.