Hope you can help. Totally new to fabric, know a little python. I'm trying to iterate through an external file of IP's to update 40 odd remote servers.
This isn't working,stops after the first IP.
Terminal command:
fab -p Password hosts update
from fabric.api import env, run, sudo
def hosts():
env.hosts = open('sat_ip_list', 'r').readlines()
def update():
sudo('apt-get update -y')
I tried the following list of IPs + Fabric script and had no problems running fab -p <password> hosts uname:
# ip_list.txt
192.168.xxx.x
127.0.0.1:xxxx
174.xxx.xxx.xxx:xxxx
# fabfile.py
from fabric.api import env, run, sudo
def hosts():
# Read ip list from ip_list.txt
env.hosts = open('ip_list.txt', 'r').readlines()
def uname():
sudo('uname -a')
What does your sat_ip_list file look like - is it one IP address per line?
Have you tried your script with just a very small number of hosts, like 2-3 IP addresses? Definitely no reason you shouldn't be able to do what you're trying to accomplish, your script basically works for me just as it is.
As a sanity check, you might want to print out the value of env.hosts, like so:
def hosts():
env.hosts = open('sat_ip_list', 'r').readlines()
print('Hosts:', env.hosts)
In my case, that results in the following output:
me#machine:~$ fab hosts
('Hosts:', ['192.168.xxx.x\n', '127.0.0.1:xxxx\n', '174.xxx.xxx.xxx:xxxx\n'])
Related
I have a .yml file present in a remote server , I want to make changes on it using python fabric. If it can be done with other python libraries feel free to share.
Thank you
You are trying to edit a line in the middle of a file which is imo is not possible.
What you can do, is making a copy of the remote file on your local machine with the desired values you want to change, and then send it back to the remote server.
from fabric import Connection as connection, task
#task
def executeTask(ctx):
with connection(host=dev_server, user=myuser) as c:
c.put('PATH_TO_YOUR_YML_FILE_LOCALLY', 'PATH_TO_YOUR_REMOTE_YML_FILE')
Don't forget to :
Replacedev_server and myuser with the remote server IP and username on it
put the code above in a file called fabfile.py and you run from your command line fab executeTask
The code above is fabric 2.4 compatible
EDIT:
Because of permissions issue you can do the following :
#task
def executeTask(ctx):
with connection(host=dev_server, user=myuser) as c:
c.put("PATH_TO_YOUR_YML_FILE_LOCALLY") # implicit to remote $HOME
c.sudo("mv YOUR_FILE_NAME YOUR_DESIRED_LOCATION") # again implicitly with a CWD of $HOME
c.sudo("chown root:root YOUR_REMOTE_FILE")
Referenc:
https://github.com/fabric/fabric/issues/1750#issuecomment-406043571
If you just need to change port number you can use sed like this
def change_port(filename):
with cd('/location'):
run('sed -i "s/old_port_number/new_port_number/g" ' +filename)
I'm trying to copy a file from my local fabric system to the multiple remote hosts using fabric put command, So, when I ran it doesn't complain anything but it does not copy the file.
Secondly, I see my remote Server already has the file, may that be an issue here? below the code.
import sys
from fabric.api import env
from fabric.operations import run, put
env.skip_bad_hosts=True
env.command_timeout=160
env.user = 'jaggle'
env.shell = "/bin/sh -c"
env.warn_only = True
env.password = '!#heyNaSaFreak'
use_sudo = True
def readhost():
env.hosts = [line.strip() for line in sys.stdin.readlines()]
def copyLDAP():
put("/Karn/ldap.conf","/etc/ldap.conf", use_sudo = True)
Below is output of the run ...
$ echo "tt-server01" | fab readhost -f OpenDgCopy.py copyLDAP
[tt-server0] Executing task 'copyLDAP'
[tt-server0] put: /Karn/ldap.conf -> /etc/ldap.conf
Done.
Disconnecting from tt-server0... done.
Instead of the readhost task, you can directly use the -H option with a comma-separated list of hosts:
fab -f OpenDgCopy.py copyLDAP -H tt-server0,tt-sever1
According to the documentation of put:
As with the OpenSSH sftp program, .put will overwrite
pre-existing remote files without requesting confirmation.
Fabric has a hosts setting to specify which computers to SSH into.
Amazon Web Services has more of a dynamic inventory that can be queried in python using tools like boto.
Is there a way to combine these two services? Ideally, I wanted something as simple as ansible's approach with an inventory file and using an external file like ec2.py.
More specifically, is there a prebaked solution for this use case? Ideally, I would like to run something straightforward like this:
from fabric.api import env, task
import ec2
env.roledefs = ec2.Inventory()
#task
def command():
run("lsb_release -a")
And run it like so, assuming env.roledefs['nginx'] exists:
$ fab -R nginx command
You can use fabric and boto concurrently.
First you need to export the aws_secret_key, aws_secret_access_key and default regions from your console. Fabric file name should be fabfile.py and should not ec2.py/other.
import boto, urllib2
from boto.ec2 import connect_to_region
from fabric.api import env, run, cd, settings, sudo
from fabric.api import parallel
import os
import sys
REGION = os.environ.get("AWS_EC2_REGION")
env.user = "ec2-user"
env.key_filename = ["/home/user/uswest.pem"]
#task
def command():
run("lsb_release -a")
def _create_connection(region):
print "Connecting to ", region
conn = connect_to_region(
region_name = region,
aws_access_key_id=os.environ.get("AWS_ACCESS_KEY_ID"),
aws_secret_access_key=os.environ.get("AWS_SECRET_ACCESS_KEY")
)
print "Connection with AWS established"
return connection
Finally this program can be executed by using below command.
$ fab command
From http://docs.python-guide.org/en/latest/scenarios/admin/
You can see that if you set
env.hosts = ['my_server1', 'my_server2']
You'll then be able to target those hosts.
With boto, if you just have a function that does
ec2_connection.get_only_instances(filter={'tag':< whatever>})
and returns a list of their dns names, you'll be able to then set
env.hosts = [< list of dns names from ec2>]
Piece of cake!
I have change my hosts file,so how to change hostname.my system is ubuntu.
eg my hosts file:
192.168.0.100 host1.mydomain.com
192.168.0.101 host2.mydomain.com
I wanna the hostname file under /etc/hostname of host1 to host1.mydomain.com,the hostname file of host2 to host2.mydomain.com
how to do that using fabric?
I have to ssh every host and edit the hostname file,does fabric can do this?
I didn't mean to use hostname command but to edit the /etc/hostname file.
I mean how to use fabric to do that:
such as:
def update_hostname():
get("/etc/hosts","hosts")
hosts_content = file("hosts")
**hostname = ·get the hostname corespond to ip·**
get("/etc/hostname","hostname")
update `hostname file`
put("hostname","/etc/hostname")
how get the ip? because fabric do the job on every host, and the hostname is correspond to each host. I need to know the which host the job is working and then get the ip back,then get the hostname correspond the the ip,and final update the hostname file.
Fabric is just a SSH wrapper, so what you're looking at is LINUX specific, not frabric or python specific.
from fabric.api import run
run('hostname your-new-name')
run('echo your-new-hostname > /etc/hostname')
And just do a run(..edit..) according to your linux dist?
Or just do:
from subprocess import Popen, PIPE
hosts = open('/etc/networking/hosts', 'rb')
for hostline in hosts.readlines():
ip, name = hostline.split(' ')
command = ['ssh', '-t', 'root#' + host.strip('\r\n ,;), ' ', "echo " + name.strip('\r\n ,;) + " > /etc/hostname",]
stdout, stderr = Popen(command, stdout=PIPE, stderr=PIPE).communicate()
hosts.close()
Note: /etc/networking/hosts might be placed somewhere else for you.
The important part here is that you loop through the /hosts file, and ssh to each machine echoing the given hostname to that machine.
def hostname():
'''
function to change the hostname of the ubuntu server
'''
server_hostname = prompt ("The Hostname for the server is :")
sed ("/etc/hostname", before='current hostname', after='%s' % (server_hostname), use_sudo=True,backup='')
sudo ("init 6")
This will change the hostname according to your choice.
in your fabric script you'll need to...
ssh into the machine as a user permitted to edit the hosts file ( via permissions or groups ). if you need to sudo into a user, search StackOverflow for issues regarding sudo and Fabric -- you'll need to tweak your fabfile to not prompt for a password.
fabric can have an awkward way to deal with reading/writing/opening files. you'll may be best off by cd into the right directory. something like...
with cd('/etc/')
run('echo new_hostname hostname')
when I run my python code it is asking for host.
No hosts found. Please specify (single) host string for connection:
I have the following code:
from fabric.api import *
from fabric.contrib.console import confirm
env.hosts = [ 'ipaddress' ]
def remoteRun():
print "ENV %s" %(env.hosts)
out = run('uname -r')
print "Output %s"%(out)
remoteRun();
I even tried running fab with -H option and I am getting the same message. I'm using Ubuntu 10.10 any help is appreciated. Btw I am a newbie in Python.
In order to get hosts to work in a script outside of the fab command-line tool and fabfile.py, you'll have to use execute():
from fabric.api import run
from fabric.tasks import execute
def mytask():
run('uname -a')
results = execute(mytask)
If it's only one host, you can use env.host_string = 'somehost or ipaddress'.
You also don’t need the ; at the end of your remoteRun.
from __future__ import with_statement
from fabric.api import *
from fabric.contrib.console import confirm
from fabric.api import env, run
env.host_string = 'ipaddress'
def remoteRun():
print "ENV %s" %(env.hosts)
out = run('uname -r')
print "Output %s"%(out)
remoteRun()
I am not exactly sure what remoteRun(); is supposed to do in your example.
Is it part of your fabfile or is this your terminal command to invoke the script?
The correct way would be a command like this in your shell:
fab remoteRun
Generally it's better to specify the concrete hosts your command is supposed to run on like this:
def localhost():
env.hosts = [ '127.0.0.1']
def remoteRun():
print "ENV %s" %(env.hosts)
out = run('uname -r')
print "Output %s"%(out)
You can run it like this from a terminal (assuming you are in the directory that contains your fabfile):
fab localhost remoteRun
As an alternative you could specify the host with the -H parameter:
fab -H 127.0.0.1 remoteRun
If you have a list of hosts you want to invoke the command for, do it like this:
http://readthedocs.org/docs/fabric/latest/usage/execution.html
Adjusted to your example:
env.hosts = [ 'localhost', '127.0.0.1']
def remoteRun():
print "ENV %s" %(env.hosts)
out = run('uname -r')
print "Output %s"%(out)
And called via: fab remoteRun
This way the remoteRun is performed on all hosts in env.hosts.
#Nerdatastic is right, for simple: don't use env.hosts, use env.host_string instead. e.g.
def setup_db_server
env.host_string = 'db01.yoursite.com' # or the ip address
run("mysqladmin ...")
end
and running $ fab setup_db_server will execute the script on the target server.
Nerdatastic is right, you need to specify the env.host_string varaible for fabric to know what host string to use. I came across this problem trying to use a subclass of Task and call the run() method. It seemed to ignore env.hosts except when using execute from fabric.tasks in version 1.3.
i have same issue.
I think this is a bug. Because all work before today.
I store my env in .fabricrc.
Now i have same message as yours. Don't know why.