How to get failed hosts in fabric

Question

I am using fabric and have a lot of hosts I have to process.

If any hosts fails I continue with execution with:

env.warn_only = True

However I want to get a list of hosts at the end that failed. How? I tried the below and I get nothing for either a success or fail.

error_list= []
success_list = []
@parallel
def my_run():
    try:
        sudo('sh test.sh')
        success_list.append(env.host)
    except:
        error_this.append(env.host)

error_list= []
success_list = []

Answer 1

Here is a code I use:

@parallel
@roles(env.roles)
def dummy_workhorse():
    return run('hostname')

@task
@runs_once
@with_settings(hide('everything'), skip_bad_hosts=True)
@needs_host
def check_hosts():
    down_hosts = []
    for host, result in execute(dummy_workhorse).iteritems():
        if not isinstance(result, str):
            down_hosts.append(host)
    if down_hosts:
        print('Following hosts are down:')
        for host in down_hosts:
            print(host)
    else:
        print('All hosts are up and running!')

Answer 2

Try using 'env.host_string' instead of 'env.host' Ref: http://docs.fabfile.org/en/1.8/usage/env.html#host-string

error_list= []
success_list = []
@parallel
def my_run():
    try:
        sudo('sh test.sh')
        success_list.append(env.host_string)
    except:
        error_list.append(env.host_string)

error_list= []
success_list = []