TurnKey Linux Virtual Appliance Library

Task configuration

Any cloudtask configuration option that can be configured from the command line may also be configured through a template default, or by defining an environment variable.

Resolution order for options:

  1. command line (highest precedence)
  2. task-level default
  3. CLOUDTASK_{PARAM_NAME} environment variable (lowest precedence)

For example, if you want to configure the ec2 region worker instances are launched in, you can configure it as:

1) The --ec2-region command line option:

$ cloudtask --ec2-region ap-southeast-1

2) By defining EC2_REGION in a task template:

$ cat > foo.py << 'EOF'

from cloudtask import Task

class Foo(Task):
    EC2_REGION = 'ap-southeast-1'

Foo.main()
EOF

$ chmod +x ./foo.py
$ ./foo.py

3) By setting the CLOUDTASK_EC2_REGION environment variable:

export CLOUDTASK_EC2_REGION=ap-southeast-1

Best practices for production use

For production use, it is recommended to create pre-configured task templates for routine jobs under revision control (e.g., Git repository). Task templates may inherit shared definitions such as the Hub APIKEY or the reporting hook from a common module:

$ cat > common.py << 'EOF'
from cloudtask import Task
class BaseTask(Task):
    HUB_APIKEY = 'BRDUKK3WDXY3CFQ'
    REPORT = 'mail: cloudtask@example.com alon@example.com liraz@example.com'

    # save sessions in the local directory ratehr than
    # $HOME/.cloudtask. That way we can easily track the session
    # logs in Git too.
    SESSIONS = 'sessions/'
EOF

$ cat > helloworld << 'EOF'
#!/usr/bin/python
from common import BaseTask
class HelloWorld(BaseTask):
    COMMAND = 'echo hello world'

HelloWorld.main()
EOF

chmod +x helloworld