oops

Today I was trying to move a file into the home directory of the current user, like this:

# mv /home/otheruser/somefile ~

Interestingly enough, after doing this for the last 15 years, I fat-fingered it like this:

# mv /home/otheruser/somefile !

CRAP!
Guess what, my file was deleted.
Btw, Mac OSX doesnt behave like this. I assume *BSD, Solaris and other high-quality systems dont as well. Pooor Linux.

SNMPv3 Quickstart

i DONT claim this to be complete or authoritative. But, with these quick steps i was able to get snmpv3 working, a generally avoided version of a widely used protocol, and a fog to many sysadmins i've worked with. I'm sick of reading 10 pages of prose to get the steps i need to move securely forward in my projects.

0) yum install net-snmp.i386 net-snmp-libs.i386

1) Run snmpconf -i to create snmpd.conf and snmp.conf
- sudo /usr/bin/snmpconf -i

Notes:
- if you're regenerating the files at some point, cd into /etc/snmp, then run `snmpconf -i`. snmpconf looks in the local dir for files first before looking elsewhere. The resultant files are still saved to /usr/local/share/snmp/
- when creating snmp.conf, complete section 3: 2-10
- when creating snmpd.conf, complete section 4: 1-3
- when creating a new user while configuring snmpd.conf, choose 'priv' for the minimum security level. you can also restrict the user to a specific branch of the OID tree here as well.

2) Copy these files to /etc/snmp

rsync -av /usr/local/share/snmp/snmp.conf /etc/snmp/
rsync -av /usr/local/share/snmp/snmpd.conf /etc/snmp/

3) Run net-snmp-config to actually create snmpv3 user, here is the correct syntax...

net-snmp-config --create-snmpv3-user [-ro] [-A authpass] [-X privpass] [-a MD5|SHA] [-x DES|AES] [username]

Here's my command that corresponds to my previous configuration of snmp.conf and the test snmpget command further below in step 5:

net-snmp-config --create-snmpv3-user -ro -A authpass -X privpass -a SHA -x AES rouser

Note: the manpage for net-snmp-config has the X and x incorrectly in their example of create-snmpv3-user. The help cruft (for net-snmp-config --help) shows it correctly. I tried to create a read-write user (with -rw), but it didnt work. I dont change system parameters through snmp anyways, so it doesnt matter to me. Maybe the absence of [-ro] creates a read-write user? seems like ro should be the default unless -rw is specified. ???

4) Restart snmpd service

5) Make test snmpv3 request

snmpget -v 3 -n "" -u rouser -a SHA -A "authpass" -x AES -X "privpass" -l authPriv localhost system.sysUpTime.0

Notes:
- The `-l authPriv` argument specifies that the request should be both signed (-a SHA) and encrypted (-x AES).
- The command above can be greatly simplfied because most of these options have been declared in the snmp.conf.

install a perl module

perl -MCPAN -e 'install Net::SNMP'

or

perl -MCPAN -w -e 'shell'

CPAN> install Net::SNMP

Deployment Tools: Puppet

I've started looking at Puppet as the next gen tool for system deployments. Check it out.

http://reductivelabs.com/trac/puppet/wiki/DocumentationStart

It leaves cfengine and others in the dust...

List all Perl Modules

perl -MFile::Find=find -MFile::Spec::Functions -Tlwe "find { wanted => sub { print canonpath $_ if /\.pm\z/ }, no_chdir => 1 }, @INC"