问题
Passing a Fabric env.hosts sting as a variable is not work in function.
demo.py
#!/usr/bin/env python
from fabric.api import env, run
def deploy(hosts, command):
print hosts
env.hosts = hosts
run(command)
main.py
#!/usr/bin/env python
from demo import deploy
hosts = ['localhost']
command = 'hostname'
deploy(hosts, command)
python main.py
['localhost']
No hosts found. Please specify (single) host string for connection:
But env.host_string works!
demo.py
#!/usr/bin/env python
from fabric.api import env, run
def deploy(host, command):
print host
env.host_string = host
run(command)
main.py
#!/usr/bin/env python
from demo import deploy
host = 'localhost'
command = 'hostname'
deploy(host, command)
python main.py
localhost
[localhost] run: hostname
[localhost] out: heydevops-workspace
But the env.host_string is not enough for us, it's a single host. Maybe we can use env.host_string within a loop, but that's not good. Because we also want to set the concurrent tasks number and run them parallelly.
Now in ddep(my deployment engine), I only use MySQLdb to get the parameters then execute the fab command like:
os.system("fab -f service/%s.py -H %s -P -z %s %s" % (project,host,number,task))
This is a simple way but not good. Because if I use the fab command, I can't catch the exceptions and failures of the results in Python, to make my ddep can "retry" the failed hosts. If I use the "from demo import deploy", I can control and get them by some codes in Python.
So now "env.host " is the trouble. Can somebody give me a solution? Thanks a lot.
回答1:
Here's my insight.
According to docs, if you're calling fabric tasks from python scripts - you should use fabric.tasks.execute.
Should be smth like this:
demo.py
from fabric.api import run from fabric.tasks import execute def deploy(hosts, command): execute(execute_deploy, command=command, hosts=hosts) def execute_deploy(command): run(command)main.py
from demo import deploy hosts = ['localhost'] command = 'hostname' deploy(hosts, command)
Then, just run python main.py. Hope that helps.
回答2:
Finally, I fixed this problem by using execute() and exec.
main.py
#!/usr/bin/env python
from demo import FabricSupport
hosts = ['localhost']
myfab = FabricSupport()
myfab.execute("df",hosts)
demo.py
#!/usr/bin/env python
from fabric.api import env, run, execute
class FabricSupport:
def __init__(self):
pass
def hostname(self):
run("hostname")
def df(self):
run("df -h")
def execute(self,task,hosts):
get_task = "task = self.%s" % task
exec get_task
execute(task,hosts=hosts)
python main.py
[localhost] Executing task 'hostname'
[localhost] run: hostname
[localhost] out: heydevops-workspace
来源：https://stackoverflow.com/questions/16209242/passing-a-fabric-env-hosts-sting-as-a-variable-is-not-work-in-function