[ale] Update ifcfg-eth0 file from command line? (need to re-ip 50 servers)

[DJ-Pfulio]

Ah ... ansible ... folks.
There's certainly a module to manage networking for RHEL systems already made.




On 03/18/2017 09:55 PM, Phil Turmel wrote:
> Aaaaahhhhhhgggg!
> 
> Raj, Leam, y'all making me cringe with those procedures.  For pity's
> sake, use mktemp to safely make an empty temp file in the *same* folder,
> stream from the original to the temp file with *one* instance of sed,
> then 'mv' the temp file back over the original.  At no point will you
> have a partially configured network -- filesystems are required to
> guarantee that renaming over file atomically replaces it.  And at no
> point will you have an unsecure temp file exposed.
> 
> Phil
> 
> On 03/18/2017 09:03 PM, Raj Wurttemberg wrote:
>> Yeah, I was actually going to do a sed to just replace the old values and do most everything in one step:
>>
>> sed -i 's/IPADDR=.*/IPADDR=1.2.3.4/' /etc/sysconfig/network-scripts/ifcfg-eth0 2> /dev/null
>> sed -i 's/BROADCAST=.*/BROADCAST=1.2.3.0/' /etc/sysconfig/network-scripts/ifcfg-eth0 2> /dev/null
>> sed -i 's/GATEWAY=.*/GATEWAY=1.2.3.1/' /etc/sysconfig/network-scripts/ifcfg-eth0 2> /dev/null
>>
>> haha... yes, I noticed a long time ago that the RHEL tries to use any file in the /etc/sysconfig/network-scripts directory! Doh!
>>
>> Thanks,
>> /Raj
>>
>>
>> -----Original Message-----
>> From: ale-bounces at ale.org [mailto:ale-bounces at ale.org] On Behalf Of Leam Hall
>> Sent: Saturday, March 18, 2017 8:32 PM
>> To: Atlanta Linux Enthusiasts <ale at ale.org>
>> Subject: Re: [ale] Update ifcfg-eth0 file from command line? (need to re-ip 50 servers)
>>
>> Untested, and I tend to do things in multiple steps.
>>
>> cp /etc/sysconfig/network-scripts/ifcfg-eth0 /tmp
>>
>> cat /tmp/ifcfg-eth0 | egrep -iv "ipaddr|broadcast|gateway" >
>> /etc/sysconfig/network-scripts/ifcfg-eth0
>>
>> echo "IPADDR=1.2.3.4" >> /etc/sysconfig/network-scripts/ifcfg-eth0
>> echo "BROADCAST=1.2.3.0" >> /etc/sysconfig/network-scripts/ifcfg-eth0
>> echo "GATEWAY=1.2.3.1" >> /etc/sysconfig/network-scripts/ifcfg-eth0
>>
>> service network restart
> 
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