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Pass a parameter to Ansible's dynamic inventory

I'm using Ansible to configure some virtual machines. I wrote a Python script which retrieves the hosts from a REST service.
My VMs are organized in "Environments". For example I have the "Test", "Red" and "Integration" environments, each with a subset of VMs.
This Python script requires the custom --environment <ENV> parameter to retrieve the hosts of the wanted environment.
The problem I'm having is passing the <ENV> to the ansible-playbook command.
In fact the following command doesn't work
ansible-playbook thePlaybook.yml -i ./inventory/FromREST.py --environment Test
I get the error:
Usage: ansible-playbook playbook.yml
ansible-playbook: error: no such option: --environment
What is the right syntax to pass variables to a dynamic inventory script?
Update:
To better explain, the FromREST.py script accepts the following parameters:
Either the --list parameter or the --host <HOST> parameter, as per the Dynamic Inventory guidelines
The --environment <ENVIRONMENT> parameter, which I added to the ones required by Ansible to manage the different Environments

I had similar issue, I didn't find any solution, so I just modified my dynamic inventory to use OS Environment variable if the user does not pass --env
Capture env var in your inventory as below:
import os
print os.environ['ENV']
Pass env var to ansible
export ENV=dev
ansible -i my_custom_inv.py all --list-host

A workaround using $PPID to parse -e/--extra-vars from process snapshot.
ansible-playbook -i inventory.sh deploy.yml -e cluster=cl_01
inventory.sh file
#!/bin/bash
if [[ $1 != "--list" ]]; then exit 1; fi
extra_var=`ps -f -p $PPID | grep ansible-playbook | grep -oh "\w*=\w*" | grep cluster | cut -f2 -d=`
./inventory.py --cluster $extra_var
inventory.py returns JSON inventory for cluster cl_01.
Not pretty I know, but works.

Fabric sudo() not respecting env.password

I'm trying to prefill env.password using --initial-password-prompt, but remote is throwing back some strangeness. Let's say that I'm trying to cat a root-owned file as testuser, with 600 permissions on the file. I'm calling sudo('cat /home/testuser/test.txt'), and getting this back:
[testuser#testserver] sudo: cat /home/testuser/test.txt
[testuser#testserver] out: cat: /home/testuser/test.txt: Permission denied
[testuser#testserver] out:
Fatal error: sudo() received nonzero return code 1 while executing!
Requested: cat /home/testuser/test.txt
Executed: sudo -S -p 'sudo password:' -u "testuser" /bin/bash -l -c "cat /home/testuser/test.txt"
Is that piping the prompt right back into the input? I tried using sudo() with pty=False to see if it was an issue with the pseudoterminal, but to no avail.
Here's the weird part: calling run('sudo cat /home/testuser/test.txt') and invoking fab without --initial-password-prompt passes back a password prompt from remote, and on entering the password, everything works fine.
Naturally, running ssh -t testuser#testserver 'sudo cat /home/user/test.txt' prompts for a password and returns the contents of the file correctly. Do I have an issue with my server's shell config, or is the issue with how I'm using sudo()?
Down the line, I'm likely to set up a deploy user with no-password sudo and restricted commands. That'll probably moot the issue, but I'd like to figure this one out if possible. I'm running an Ubuntu 14.10 VPS, in case that's relevant.

Oh, my mistake. I had foolishly set env.sudo_user to my deploy user testuser, thinking that it was specifying the invoking user on remote. In fact, it was specifying the target user, and I was attempting to sudo into myself. Whoops.

How can I run a django management command by cron job

I am working with a django app called django-mailbox. The purpose of this is to import email messages via pop3 and other protocols and store them in a db. I want to do this at regular intervals via a chron. In the documentation http://django-mailbox.readthedocs.org/en/latest/topics/polling.html it states:
Using a cron job
You can easily consume incoming mail by running the management command named getmail (optionally with an argument of the name of the mailbox you’d like to get the mail for).:
python manage.py getmail
Now I can run this at the command line locally and it works but if this was deployed to an outside server which was only accessible by a URL how would this command be given?

If you are using a virtual env use the python binary from the virtualenv
* * * * * /path/to/virtualenv/bin/python /path/to/project/manage.py management_command

on the server machine:
$ sudo crontab -l
no crontab for root
$ sudo crontab -e
no crontab for root - using an empty one
Select an editor. To change later, run 'select-editor'.
1. /bin/ed
2. /bin/nano <---- easiest
3. /usr/bin/vim.basic
4. /usr/bin/vim.tiny
Choose 1-4 [2]:
choose your preferred editor
then see http://en.wikipedia.org/wiki/Cron for how to schedule when will the command run, direct it to some .sh file on your machine, make sure you give full path as this is going to run in root user context.
the script the cron will run may look something like:
#!/bin/bash
cd /absolute/path/to/django/project
/usr/bin/python ./manage.py getmail

Running fabric scripts as root

I am trying to use fabric to automate some administrative work that I am doing on a couple of servers. The general flow is the following:
SSH with local user
run: sudo su - to become root (providing local user password again)
Do the work as root :)
Unfortunately using run('sudo su -') blocks execution of the scripts and allows user input. When I type exit or Ctrl+D the scipt resumes, but without root privileges.
I have seen a similar problem in Switching user in Fabric but I am restricted to sudo su - because I am not allowed to change the /etc/sudoers file which contains the following line:
localuser ALL = /usr/bin/su -
I browsed the source of fabric trying to find a workaround but with no success.

Having faced the same problem as yours, (only sudo su - user allowed by admin, sudo -u user -c cmd not allowed), here's my working solution with fabric:
from ilogue.fexpect import expect, expecting, run
def sudosu(user, cmd):
cmd += ' ;exit'
prompts = []
prompts += expect('bash', cmd)
prompts += expect('assword:', env.password)
with expecting(prompts):
run('sudo su - ' + user)
def host_type():
sudosu('root', 'uname -s')

There are several solutions for your issue. First, you want to run commands using sudo. You can use the fabric method sudo instead of run that runs a shell command on a remote host, with superuser privileges(sudo ref).
For example, these commands are executed using sudo :
sudo("~/install_script.py")
sudo("mkdir /var/www/new_docroot", user="www-data")
sudo("ls /home/jdoe", user=1001)
result = sudo("ls /tmp/")
Another idea is that you want to wrap a set of commands (that need to be sudoed).
You can use Fabric context managers (ref) to do that. Particularly, you can use prefix or settings.
For example:
with settings(user='root'):
run('do something')
run('do another thing')
will ask you once the root password then execute commands as root.
You can tweek settings to store the password.

There is one solution for the following problem Sorry, user localuser is not allowed to execute '/usr/bin/su - -c /bin/bash -l -c pwd' as root on hostname.
You can try sudo('mkdir ~/test_fabric',shell=False). Using param shell to avoid the bash param -l.

Can I prevent fabric from prompting me for a sudo password?

I am using Fabric to run commands on a remote server. The user with which I connect on that server has some sudo privileges, and does not require a password to use these privileges. When SSH'ing into the server, I can run sudo blah and the command executes without prompting for a password. When I try to run the same command via Fabric's sudo function, I get prompted for a password. This is because Fabric builds a command in the following manner when using sudo:
sudo -S -p <sudo_prompt> /bin/bash -l -c "<command>"
Obviously, my user does not have permission to execute /bin/bash without a password.
I've worked around the problem by using run("sudo blah") instead of sudo("blah"), but I wondered if there is a better solution. Is there a workaround for this issue?

Try passing shell=False to sudo. That way /bin/bash won't be added to the sudo command. sudo('some_command', shell=False)
From line 503 of fabric/operations.py:
if (not env.use_shell) or (not shell):
real_command = "%s %s" % (sudo_prefix, _shell_escape(command))
the else block looks like this:
# V-- here's where /bin/bash is added
real_command = '%s %s "%s"' % (sudo_prefix, env.shell,
_shell_escape(cwd + command))

You can use:
from fabric.api import env
# [...]
env.password = 'yourpassword'

In your /etc/sudoers file add
user ALL=NOPASSWD: some_command
where user is your sudo user and some_command the command you want to run with fabric, then on the fabric script run sudo it with shell=False:
sudo('some_command', shell=False)
this works for me

In your /etc/sudoers file, you could add
user ALL=NOPASSWD: /bin/bash
...where user is your Fabric username.
Obviously, you can only do this if you have root access, as /etc/sudoers is only writable by root.
Also obviously, this isn't terribly secure, as being able to execute /bin/bash leaves you open to essentially anything, so if you don't have root access and have to ask a sysadmin to do this for you, they probably won't.

Linux noob here but I found this question while trying to install graphite-fabric onto an EC2 AMI. Fabric kept prompting for a root password.
The evntual trick was to pass in the ssh private key file to fabric.
fab -i key.pem graphite_install -H root#servername

You can also use passwords for multiple machines:
from fabric import env
env.hosts = ['user1#host1:port1', 'user2#host2.port2']
env.passwords = {'user1#host1:port1': 'password1', 'user2#host2.port2': 'password2'}
See this answer: https://stackoverflow.com/a/5568219/552671

I recently faced this same issue, and found Crossfit_and_Beer's answer confusing.
A supported way to achieve this is via using env.sudo_prefix, as documented by this github commit (from this PR)
My example of use:
env.sudo_prefix = 'sudo '