This systemd startup script refuses to run, but I just can't figure out why.
[Unit]
Description=IP Address on Boot Screen
[Service]
ExecStart=/usr/bin/ifconfig eth0 | awk '/inet / {print $2}' | cut -f2 -d: > /etc/issue
[Install]
WantedBy=multi-user.target
Obviously the problem is with the ExecStart but I just can't see any errors with it!
You are passing a shell command. At the time systemd starts there is no shell and no environment variables set.
Thus, systemd does not know how to handle awk, because there is no $PATH.
Set ExecStart= option to something like:
/bin/sh -c '/usr/bin/ifconfig eth0 | /bin/awk \'/inet / {print $2}\' | /bin/cut -f2 -d: > /etc/issue'
Related
I'm working on a script, that should find certain disks and add hostname to them.
I'm using this for 40 servers with a for loop in bash
#!/bin/bash
for i in myservers{1..40}
do ssh user#$i findmnt -o SIZE,TARGET -n -l |
grep '1.8T\|1.6T\|1.7T' |
sed 's/^[ \t]*//' |
cut -d ' ' -f 2 |
awk -v HOSTNAME=$HOSTNAME '{print HOSTNAME ":" $0}'; done |
tee sorted.log
can you help out with the quoting here? It looks like awk gets piped (hostname) from localhost, not the remote server.
Everything after the first pipe is running locally, not on the remote server.
Try quoting the entire pipeline to have it run on the remote server:
#!/bin/bash
for i in myservers{1..40}
do ssh user#$i "findmnt -o SIZE,TARGET -n -l |
sed 's/^[ \t]*//' |
cut -d ' ' -f 2 |
awk -v HOSTNAME=\$HOSTNAME '{print HOSTNAME \":\" \$0}'" ;
done | tee sorted.log
This is a shorter version of your stuff:
findmnt -o SIZE,TARGET -n -l |
awk -v HOSTNAME=$HOSTNAME '/M/{print HOSTNAME ":" $2}'
Applied to the above:
for i in myservers{1..40}
do ssh user#$i bash -c '
findmnt -o SIZE,TARGET -n -l |
awk -v HOSTNAME=$HOSTNAME '"'"'/M/{print HOSTNAME ":" $2}'"'"' '
done |
tee sorted.log
see: How to escape the single quote character in an ssh / remote bash command?
I am trying to kill all the existing processes before checkout the code and build it, in order to do, I am using the below command.
sudo ps -ef | grep 'dotnet' | grep -v grep | awk '{print $2}' | xargs -r kill -9;
This is working fine when I run it in the server manually. whereas, using in the jenkins pipeline as Execute Shell script, its not working.
Here is the jenkin's output
**-----------
[CICD] $ /bin/sh -xe /tmp/jenkins6283168714008394634.sh
+ ps -ef
+ grep dotnet
+ grep -v grep
+ + awk {print $2}xargs
-r kill -9
Failed build for hudson.tasks.Shell#178f47d3
**------------
Can someone please help?
I'm trying to create a command that will automatically attach to my existing python docker container, and trying to chain a bunch of commands together.
docker ps | grep "mypythoncontainer" | awk '{print $1}' | xargs docker attach
If I run
docker ps | grep "mypythoncontainer" | awk '{print $1}' | xargs echo
I get back a docker id string, as expected. And if I do docker attach {id string} (copied from the return of the statement right above this), it works. But when I run the full command at top, I get an error (the input device is not a TTY).
So docker ps | grep "mypythoncontainer" | awk '{print $1}' | xargs echo would echo out abc, but docker ps | grep "mypythoncontainer" | awk '{print $1}' | xargs docker attach would fail, while docker attach abc works. Not sure what about xargs I don't understand.
Try:
docker attach $(docker ps | grep "mypythoncontainer" | awk '{print $1}')
or simplier:
docker attach $(docker ps | awk '/mypythoncontainer/{print $1}')
Not sure what about xargs I don't understand.
Running: ...| ... docker ... will redirect docker's standard input to ... the ouput of awk, wich was already read by xargs. So docker abc will r
un with a broken (already closed) STDIN, then fail.
I'm trying to create script to be run by cron to create multiple folders with subfolders.
DATE=`date +%Y-%m-%d`
IP_ADDR=`ifconfig | grep -v '127.0.0.1' | sed -n 's/.*inet addr:\([0-9.]\+\)\s.*/\1/p'`
/bin/mkdir -p /mnt/db-backup/12/$DATE/$IP_ADDR/
If i run this script manually everything is created as expected. When script is ran by cron subdirectory $IP_ADDR is not created and there is no errors.
I suspect that /sbin is not part of the PATH for the environment that the cron job runs under. You should specify the full path for the ifconfig command:
IP_ADDR=$(/sbin/ifconfig | grep -v '127.0.0.1' | sed -n 's/.*inet addr:\([0-9.]\+\)\s.*/\1/p')
It's also better practice (in general) to use $() for command substitution.
Try to use debug mode :
set -x
DATE=`date +%Y-%m-%d`
IP_ADDR=`ifconfig | grep -v '127.0.0.1' | sed -n 's/.*inet addr:\([0-9.]\+\)\s.*/\1/p'`
/bin/mkdir -p /mnt/db-backup/12/$DATE/$IP_ADDR/
set +x
Then, redirect the output of your cron to a file and have a look, you should find useful information in it.
You are not far off, but there are several ordering caveats that could cause problems. Many systems have different formats for the ifconfig output line. Some with inet xxx.xxx.xxx.xxx, others with inet addr:xxx.xxx.xxx.xxx. (those are the two most common). You may also need to handle the case where there are multiple wired inet interfaces (2+ NICs in the box). However, if you have only 1 NIC, you could try the following to handle the common ifconfig formats:
DATE=`date +%Y-%m-%d`
IP_ADDR=$(ifconfig |
grep -v '127.0.0.1' |
grep -E 'inet[ ](addr:)*[0-9]{1,3}([.][0-9]{1,3}){3}' |
sed -e 's/^.*inet \(addr:\)*//' -e 's/ .*$//')
/bin/mkdir -p /mnt/db-backup/12/$DATE/$IP_ADDR/
or with IP_ADDR written as one line:
IP_ADDR=$(ifconfig | grep -v '127.0.0.1' | grep -E 'inet[ ](addr:)*[0-9]{1,3}([.][0-9]{1,3}){3}' | sed -e 's/^.*inet \(addr:\)*//' -e 's/ .*$//')
I am executing sshd in a bash script using
$ /usr/sbin/sshd
How do I get the process ID of this sshd that I executed?
sshd will typically write a PID file; by default this is at /var/run/sshd.pid. You can use this to find the process ID of the listening sshd process. You should be aware that sshd may fork several subprocesses as it works, so what you want really depends on what you intend to do with it.
Try this command:
ps aux | grep -e /usr/sbin/sshd | grep -v grep | tr -s " " | cut -d " " -f2
or
cat /var/run/sshd.pid