I am kicking machines with cobbler to install redhat 6 and also put in hostname.
I am managing my machines with /etc/hosts file right now (may switch to dns in the future) and would like to have puppet (or anything that will work) parse through /etc/hosts and find my ip address and hostname (based on the hostname supplied by cobbler at kickstart). The trick is that some machines have multiple IP's and hostnames in the /etc/hosts file, like such:
# Maintenance Network
192.168.80.192 testsrv01-maint
192.168.80.193 testsrv02-maint
192.168.80.194 testsrv03-maint
# Lights Out Network
192.168.120.192 testsrv01-ilo
192.168.120.193 testsrv02-ilo
192.168.120.194 testsrv03-ilo
# Primary Data Network
192.168.150.192 testsrv01-pri
192.168.150.193 testsrv02-pri
192.168.150.194 testsrv03-pri
# Secondary Data Network
192.168.200.192 testsrv01-sec
192.168.200.193 testsrv02-sec
192.168.200.194 testsrv03-sec
I need to capture each ip and hostname pair (in a line) and transpose into /etc/sysconfig/network-scripts/ifcfg-eth* (eth1, eth2, eth3, ...). Puppet will need to create as many ifcfg-eth* files as there are matches in /etc/hosts for the hostname.
I just need puppet to append the $IP and $hostname to the ifcfg-eth file, the rest of the content is common.
So how would I get 4x ifcfg-eth files for 'testsrv01', with puppet?
Puppet is a very ill fit for this task. This calls for a script, which Puppet does not support. Puppet allows you to declare a piece of machine state that can portably enforced on different platforms.
The task is simple enough for a Shell or Perl Script.
With Puppet, it would entail the following scripts
writing custom facts to retrieve each address / hostname pair
devising a defined type to render such a pair into an ethX file
You'd possibly even need to generate the respective manifest, so that the appropriate interface index is chosen for each address.
All things considered, you would not make use of Puppet's strengths and suffer some of its weaknesses.
Related
I know this code works on Windows, but how do I get workable code executable on MacOS?
netsh -c interface ipv4 add neighbors "(connection name)" "(router
address)" "(mac address)" store=persistent
Any suggestions please...
try typing "man arp" into the terminal. Something like this might work :
arp -s hostname ether_addr
Create an ARP entry for the host called hostname with the Ethernet address ether_addr. The Ethernet address is
given as six hex bytes separated by colons. The entry will be permanent unless the word temp is given in the
command. If the word pub is given, the entry will be ``published''; i.e., this system will act as an ARP server,
responding to requests for hostname even though the host address is not its own. In this case the ether_addr can
be given as auto in which case the interfaces on this host will be examined, and if one of them is found to
occupy the same subnet, its Ethernet address will be used. If the only keyword is also specified, this will cre-
ate a ``published (proxy only)'' entry. This type of entry is created automatically if arp detects that a rout-
ing table entry for hostname already exists.
I've a hosts file with 4 host ip's and I'm always using "ansible_connection=ssh ansible_ssh_user=user ansible_ssh_pass=pass" besides host ip to verify the connection.
But, this is difficult to add these many times. Could someone please tell me where can I keep common these parameters and pass it to all my host ip's at a time?
Create file in directory all in directory group_vars with the content.
ansible_connection:ssh
ansible_ssh_user:user
ansible_ssh_pass:pass
It should work.
I've been trying to implement Ansible in our team to manage different kinds of application things such as configuration files for products and applications, the distribution of maintenance scripts, ...
We don't like to work with "hostnames" in our team because we have 300+ of them with meaningless names. Therefor, I started out creating aliases for them in the Ansible hosts file like:
[bpm-i]
bpm-app1-i1 ansible_user=bpmadmin ansible_host=el1001.bc
bpm-app1-i2 ansible_user=bpmadmin ansible_host=el1003.bc
[bpm-u]
bpm-app1-u1 ansible_user=bpmadmin ansible_host=el2001.bc
bpm-app1-u2 ansible_user=bpmadmin ansible_host=el2003.bc
[bpm-all:children]
bpm-i
bpm-u
Meaning we have a BPM application named "app1" and it's deployed on two hosts in integration-testing and on two hosts in user-acceptance-testing. So far so good. Now I can run an Ansible playbook to (for example) setup the SSH accesses (authorized_keys) for team members or push a maintenance script. I can run those PBs on each host seperately, on all hosts ITT or UAT or even everywhere.
But, typically, we'll have install the same application app1 again on an existing host but with a different purpose - say "training" environment. My reflex would be to do this:
[bpm-i]
bpm-app1-i1 ansible_user=bpmadmin ansible_host=el1001.bc
bpm-app1-i2 ansible_user=bpmadmin ansible_host=el1003.bc
[bpm-u]
bpm-app1-u1 ansible_user=bpmadmin ansible_host=el2001.bc
bpm-app1-u2 ansible_user=bpmadmin ansible_host=el2003.bc
[bpm-t]
bpm-app1-t1 ansible_user=bpmadmin ansible_host=el2001.bc
bpm-app1-t2 ansible_user=bpmadmin ansible_host=el2003.bc
[bpm-all:children]
bpm-i
bpm-u
bpm-t
But ... running PB's becomes a mess now and cause errors. Logically I have two alias names to reach the same user/host combination : bpm-app1-u1 and bpm-app1-t1. I don't mind, that's perfectly logical, but if I were to test a new maintenance script, I would first push it to bpm-app1-i1 for testing and when ok, I probably would run the PB against bpm-all. But because of the non-unique user/host combinations for some aliases the PB would run multiple times on the same user/host. Depending on the actions in the PB this may work coincidentally, but it may also fail horribly.
Is there no way to tell Ansible "Run on ALL - UNIQUE user/host combinations" ?
Since most tasks change something on the remote host, you could use Conditionals to check for that change on the host before running.
For example, if your playbook has a task to run a script that creates a file on the remote host, you can add a when clause to "skip the task if file exists" and check for the existence of that file with a stat task before that one.
- Check whether script has run in previous instance by looking for file
stat: path=/path/to/something
register: something
- name: Run Script when file above does not exist
command: bash myscript.sh
when: not something.exists
How do I configure rsyslog to write raw IP addresses instead of DNS names in log files for remote hosts?
In Debian, open /etc/defaults/rsyslog and modify:
RSYSLOGD_OPTIONS="-x -Q"
and then:
# service rsyslog restart
See man rsyslogd(8) for other possible options. This doesn't disable DNS names for all remote hosts, only some of them.
I use
fromhost-ip
instead of
hostname or source
fromhost-ip reference the host that send the packet to this rsyslog. It meant that if you have any relay intermediate system, the last one is the IP that you see. If you don't use relay this is a valid solution.
You need to create a new template and apply it on /etc/rsyslog.conf. You should create like these on:
$template myFormat,"%timegenerated% %HOSTNAME% %syslogtag%%msg%\n"
$ActionFileDefaultTemplate myFormat
I have private DNS servers and I want to write them to resolv.conf with resolvconf on Debian on AWS/EC2.
There is a problem in the order of nameserver entries.
In my resolv.conf, EC2's default nameserver is always written at first line like so:
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 172.16.0.23
nameserver 10.0.1.185
nameserver 10.100.0.130
search ap-northeast-1.compute.internal
172.16.0.23 is EC2's default nameserver and others are mine.
How to remove EC2 entry? Or, how to move EC2 entry to third?
Here I have an interface file:
% ls -l /etc/resolvconf/run/interface/
-rw-r--r-- 1 root root 62 Jun 7 23:35 eth0
It seems that the file eth0 is automatically generated by dhcp so can't remove it permanently.
% cat /etc/resolvconf/run/interface/eth0
search ap-northeast-1.compute.internal
nameserver 172.16.0.23
My private DNS entry is here:
% cat /etc/resolvconf/resolv.conf.d/base
nameserver 10.0.1.185
nameserver 10.100.0.130
Please help.
I think I just solved a very similar problem. I was bothered by Amazon EC2's crappy internal DNS servers so I wanted to run a local caching dnsmasq daemon and use that in /etc/resolv.conf. At first I just did echo nameserver 127.0.0.1 > /etc/resolv.conf but then I realized that my change would eventually be overwritten by the DHCP client after a reboot or DHCP lease refresh.
What I've now done instead is to edit /etc/dhcp3/dhclient.conf and uncomment the line prepend domain-name-servers 127.0.0.1;. You should be able to use the prepend directive in a very similar way.
Update: These instructions are based on Ubuntu Linux but I imagine the general concept applies on other systems as well, even other DHCP clients must have similar configuration options.
I'm approaching this problem from the other direction (wanting the internal nameservers), much of what I've learned may be of interest.
There are several options to control name resolution in the VPC management console.
VPC -> DHCP option sets -> Create dhcp option set
You can specify your own name servers there.
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_DHCP_Options.html
Be sure to attach this dhcp option set to your VPC to get it to take effect.
Alternatively (I found this out by mistake) local dns servers are not set if the following settings are disabled in VPC settings:
DnsHostnames
and
DnsSupport
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-dns.html
Settings can also be overridden locally (which you'll notice if you move instances between vpcs). /etc/dhcp/dhclient.conf
The following line might be of interest:
prepend domain-name-servers
Changes, of course, take effect on dhclient start.
How do I assign a static DNS server to a private Amazon EC2 instance running Ubuntu, RHEL, or Amazon Linux?
Short Description
Default behavior for an EC2 instance associated with a virtual private cloud (VPC) is to request a DNS server address at startup using the Dynamic Host Configuration Protocol (DHCP). The VPC responds to DHCP requests with the address of an internal DNS server. The DNS server addresses returned in the DHCP response are written to the local /etc/resolv.conf file and are used for DNS name resolution requests. Any manual modifications to the resolv.conf file are overwritten when the instance is restarted.
Resolution
To configure an EC2 instance running Linux to use static DNS server entries, use a text editor such as vim to edit the file /etc/dhcp/dhclient.conf and add the following line to the end of the file:
supersede domain-name-servers xxx.xxx.xxx.xxx, xxx.xxx.xxx.xxx;
Ubuntu - dhclient.conf - DHCP client configuration file
The supersede statement
supersede [ option declaration ] ;
If for some option the client should always use a locally-configured value or values
rather than whatever is supplied by the server, these values can be defined in the
supersede statement.
The prepend statement
prepend [ option declaration ] ;
If for some set of options the client should use a value you supply, and then use the
values supplied by the server, if any, these values can be defined in the prepend
statement. The prepend statement can only be used for options which allow more than one
value to be given. This restriction is not enforced - if you ignore it, the behaviour
will be unpredictable.
The append statement
append [ option declaration ] ;
If for some set of options the client should first use the values supplied by the server,
if any, and then use values you supply, these values can be defined in the append
statement. The append statement can only be used for options which allow more than one
value to be given. This restriction is not enforced - if you ignore it, the behaviour
will be unpredictable.
In here someone come with solution that basically replaces the file on boot using rc.local
https://forums.aws.amazon.com/thread.jspa?threadID=74497
Edit /etc/sysconfig/network-scripts/ifcfg-eth0 to say PEERDNS=no
Create a file called /etc/resolv.backup with what you want
Add the following 2 lines to /etc/rc.local:
rm -f /etc/resolv.conf cp /etc/resolv.backup /etc/resolv.conf
This is what we are doing for our servers in the environment.
interface "eth0"
{
prepend domain-name-servers 10.x.x.x;
supersede host-name "{Hostname}";
append domain-search "domain";
supersede domain-name "DOMAIN";
}
Hope this helps.
The following worked in a Debian stretch on AWS EC2.
Just create /etc/dhcp/dhclient-enter-hooks.d/nodnsupdate:
#!/bin/sh
make_resolv_conf(){
:
}
Then you can modify /etc/resolv.conf and it will persist your changes across restarts.
Setup in crontab as
#reboot cp -r /home/.../resolv.conf /etc/resolv.conf