Getting Started

You can quickly get started with pyflow with a trivial example outlined below. Before you run it, make sure to setup your environment by following instructions in Installation chapter.

Write Suite

Copy the following code into a new file called hello_pyflow.py:

import os
from pwd import getpwuid

import pyflow as pf


scratchdir = os.path.join(os.path.abspath(''), 'scratch')
filesdir = os.path.join(scratchdir, 'files')
outdir = os.path.join(scratchdir, 'out')

if not os.path.exists(filesdir):
    os.makedirs(filesdir, exist_ok=True)

if not os.path.exists(outdir):
    os.makedirs(outdir, exist_ok=True)

passwd = getpwuid(os.getuid())

server_host = 'localhost'
server_port = 1500+passwd.pw_uid

with pf.Suite('hello_pyflow',
              host=pf.LocalHost('localhost'),
              files=filesdir,
              home=outdir,
              defstatus=pf.state.suspended) as s:
    pf.Label('greeting', '')
    t1 = pf.Task('t1', script='echo "I am on $(hostname) : $ECF_HOST"')
    t2 = pf.Task('t2', script='ecflow_client --alter=change label greeting "Hello, pyflow!" /hello_pyflow')
    t1 >> t2

s.check_definition()
print(s)

s.deploy_suite()
s.replace_on_server(server_host, server_port)

Start Server

Before you can deploy suite, make sure to start a local ecFlow server, via command line:

ecflow_start.sh

Make a note of your ecFlow server Port Number, which will be shown by the command above. By default, this value is dynamic and will be set to 1500 + UID, where UID is your current user ID.

Deploy Suite

To deploy the suite, simply run the Python script from the command line:

python3 hello_pyflow.py

Run Suite

You can run the suite from the ecFlowUI application. Either start it via system menu icon or via command line:

ecflow_ui

If running for the first time, turn on the Administrator menu mode in Tools > Preferences:

Then, add the local server to the view via Servers > Manage servers > Add server dialog, taking care to substitute the Port Number value, which was shown when you started the ecFlow server:

To queue the deployed suite, right click on it in the tree and choose Begin from the context menu:

Finally, to resume the suite, right click on it and choose Resume from the context menu:

The suite should now run and you should see the nodes change colour depending on their state and label get updated. Note that you can refresh the server view at any time by clicking on appropriate toolbar button or via F5 keyboard shortcut.

Stop Server

After you finish, make sure to stop the local ecFlow server:

ecflow_stop.sh