I need to write a korn script that depending on the host the script is running on, will set a deployment directory (so say 5 hosts deploy the software to directory one and five other hosts deploy to directory two).
How could I do this - I wanted to avoid an if condition for every host like below
IF [hostname = host1] then $INSTALL_DIR=Dir1
ELSE IF [hostname = host2] then $INSTALL_DIR=Dir1
and would prefer to have a list of say Directory1Hosts and Directory2Hosts which contains all the hosts valid for each directory, and then I would just check if the host the script is running on is in my Directory1Hosts or Directory2Hosts (so only two IF conditions instead of 10).
Thanks for your help - have been struggling to find how to do effectively a contains clause.
Use a case statement:
case $hostname in
host1) INSTALL_DIR=DIR1 ;;
host2) INSTALL_DIR=DIR2 ;;
esac
or use an associative array
install_dirs=([host1]=DIR1 [host2]=DIR2)
...
INSTALL_DIR=${install_dirs[$hostname]}
When you want to have configuration and code apart, you can make a config directory: one file with hosts for each install dir.
# cat installdirs/Dir1
host1
host2
With these files your code can be
INSTALL_DIR=$(grep -Flx "${hostname}" installdirs/* | cut -d"/" -f2)
Related
I am trying to create an autocomplete script for scp.
The script reads the user and hostname from my .ssh/config file
My .ssh/config file looks like:
Host host1
HostName host1
User userA
port 22
Host host2
HostName host2
User userB
port 22
Host host3
HostName host3
User userB
port 22
My .autocomplete_scp.sh file is:
# SSH
function _scp_completion() {
pcregrep -o -M 'HostName [a-zA-Z.]+[\n\t\s]+User [a-zA-Z]+'
$HOME/.ssh/config | awk 'NR % 2 == 1 { o=$2 ; next } { print $2"#"o}'
}
complete -W "$(_scp_completion)" scp
I source this file in my bashrc.
Now when I type userA and press Tab, the autocomplete function will give me userA#host1. When I type userB and hit Tab, the autocomplete function will give me userB#, but I am not able to get the full string (userB#host2 or userB#host3).
It also doesn't work when I type userA#h and hit the Tab button twice. So it seems to get stuck due to the # sign.
(When I remove the # sign from the _scp_completion function it works fine.)
Any ideas to fix this? Thanks!
The easy way to make it work is to remove '#' from $COMP_WORDBREAKS or Bash would handle # by itself. You can try like this:
COMP_WORDBREAKS=${COMP_WORDBREAKS//#}
complete -W 'userA#host1 userB#host2 userB#host3' scp
According to bash doc:
COMP_WORDBREAKS
The set of characters that the readline library treats as word separators when performing word completion.
When I'm hardcoding i. e.
server1=ip-10.237.40.10-aws-n-myhost
ssh - i /home/<passwordfile> akhil#$server1
It is working,but when I'm greping the host from other file its not working
Eg:
server2=$(grep - e host /home/akhil/configuration. File | awk FS, '{print $2} ' )
echo $server2
ssh - i /home/<passwordfile> akhil#$server2
While printing server 2 is fine, but when it is used in ssh I'm getting a error saying : not known host name.
I want to automate the script with a configuration file so that when ever the cluster changes I could simply change the ip address in configfile instead of changing in all my scripts.
I need help in this.
Thanks
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
I am using puppet for provisioning to AWS cloud. I am a newbie to this.
My requirement is to add entry into /etc/hosts file of amazon ec2 instance. However at the time of writing puppet, I do not know the actual hostname.
How can I use $HOSTNAME variable in .pp file?
Something like this -
host { '$HOSTNAME':
ip => 'echo $HOSTNAME | tr "-" "." | sed 's/ip.//'',
host_aliases => 'mywebsite',
}
Something like this :
host { $fqdn :
ip => $ipaddress,
host_aliases => 'mywebsite',
}
$fqdn provides fully qualified domain name and $ipaddress provides IP address for the machine. These variables are available if you have facter installed in your system. facter is available at the puppetlab repo. You can install it the same way you installed puppet in your system.
As in the comment, you can also use $hostname to get the short-hostname in place of $fqdn.
Since I wanted the hosts file to be updated before startup script's start gets executed, I did this and it worked for me.
Added this in /etc/init.d/
setup_hostname() {
IPADDR=`echo $HOSTNAME | tr "-" "." | sed 's/ip.//'`
echo "${IPADDR} ${HOSTNAME}" >> /etc/hosts
}
Called setup_hostname from start
case "$1" in
start)
clean
setup_hostname
start
;;
The Problem
I have a script that has a case statement which I'm expecting to execute based on the value of a variable. The case statement appears to either ignore the value or not properly evaluate it instead dropping to the default.
The Scenario
I pull a specific character out of our server hostnames which indicates where in our environment the server resides. We have six different locations:
Management(m): servers that are part of the infrastructure such as monitoring, email, ticketing, etc
Development(d): servers that are for developing code and application functionality
Test(t): servers that are used for initial testing of the code and application functionality
Implementation(i): servers that the code is pushed to for pre-production evaluation
Production(p): self-explanatory
Services(s): servers that the customer needs to integrate that provide functionality across their project. These are separate from the Management servers in that these are customer servers while Management servers are owned and operated by us.
After pulling the character from the hostname I pass it to a case block. I expect the case block to evaluate the character and add a couple lines of text to our rsyslog.conf file. What is happening instead is that the case block returns the default which does nothing but tell the person building the server to manually configure the entry due to an unrecognized character.
I've tested this manually against a server I recently built and verified that the character I am pulling from the hostname (an 's') is expected and accounted for in the case block.
The Code
# Determine which environment our server resides in
host=$(hostname -s)
env=${host:(-8):1}
OLDFILE=/etc/rsyslog.conf
NEWFILE=/etc/rsyslog.conf.new
# This is the configuration we need on every server regardless of environment
read -d '' common <<- EOF
...
TEXT WHICH IS ADDED TO ALL CONFIG FILES REGARDLESS OF FURTHER CODE EXECUTION
SNIPPED
....
EOF
# If a server is in the Management, Dev or Test environments send logs to lg01
read -d '' lg01conf <<- EOF
# Relay messages to lg01
*.notice ##xxx.xxx.xxx.100
#### END FORWARDING RULE ####
EOF
# If a server is in the Imp, Prod or is a non-affiliated Services zone server send logs to lg02
read -d '' lg02conf <<- EOF
# Relay messages to lg02
*.notice ##xxx.xxx.xxx.101
#### END FORWARDING RULE ####
EOF
# The general rsyslog configuration remains the same; pull it out and write it to a new file
head -n 63 $OLDFILE > $NEWFILE
# Add the common language to our config file
echo "$common" >> $NEWFILE
# Depending on which environment ($env) our server is in, add the appropriate
# remote log server to the configuration with the $common settings.
case $env in
m) echo "$lg01conf" >> $NEWFILE;;
d) echo "$lg01conf" >> $NEWFILE;;
t) echo "$lg01conf" >> $NEWFILE;;
i) echo "$lg02conf" >> $NEWFILE;;
p) echo "$lg02conf" >> $NEWFILE;;
s) echo "$lg02conf" >> $NEWFILE;;
*) echo "Unknown environment; Manually configure"
esac
# Keep a dated backup of the original rsyslog.conf file
cp $OLDFILE $OLDFILE.$(date +%Y%m%d)
# Replace the original rsyslog.conf file with the new version
mv $NEWFILE $OLDFILE
An Aside
I've already determined that I can combine the different groups of code from the case block onto single lines (a total of two) using the | operator. I've listed it in the manner above since this is how it is coded while I'm having issues with it.
I can't see what's wrong with your code. Maybe add another ;; to the default clause. To find the problem add a set -vx as a first line. Will show you lots of debug information.