Shell One-liners and scripts

Filesystem

Files

Find files with specific type, containing a pattern e.g. get all yml files, containing networks 10.168 and 10.99

find . -type f -name "*.yml" -maxdepth 1 \
  -exec grep -q 10.168 {} \; -a \
  -exec grep -q 10.99 {} \; -a -print

Find all files here containing a specific string, and replace it. e.g. get all files recursively containing a port 6379 and replace it with 6399

find . -type f \                                                           
    -exec grep -r ' 6379' {} ';' \
    -exec sed -i '' 's/ 6379/ 6389/g' {} +

Iterate over an array and exec e.g. get the list of conf files, for every file print the filename and the content

t=($(ls *.conf)) && for i in "${t[@]}";do echo $i && cat $i  ;done

Find number of files per dir e.g. find and print recursively the current number of files per dir

for i in `ls -1A`; do echo "`find $i | sort -u | wc -l` $i"; done | sort -rn | head -5

Iterate over two files e.g for each line containing the hostname of hostname_list_online, find in the list hostname_list_all and print it.

while read j; do [ -z "$(grep -w $j hostname_list_all)" ] && echo $j ; done < hostname_list_online

Iterate over multiple files, arrays and exec commands e.g. refresh ex and tempfile files, sort tt to tempfile, crete tm with a specific format`. create an array with all lines , sort and clean it.

crete the new ex file, and remove each line of ex file, from tempfile.

>  ex | > tempfile | sort -r -V tt > tempfile && \
tm=($(cat tempfile | awk -F ".v" '{print $1}')) && \
ttt=($(echo "${tm[@]}" | tr ' ' '\n' | sort -u | tr '\n' ' ')) && \
for i in "${ttt[@]}";do grep $i tempfile | head -n2 >> ex;done && \
while read j; do sed -i "/$j/d" tempfile; done < ex

Performance

Get sum of RSS Memory

ps aux | awk '{x +=$6} END {print x/1024}'

Kubernetes

Get annotation info for specific kind in all namespaces e.g. get value of ingress.class for all ingresses

kubectl get ing -A -o json |  jq '.items[] | .metadata.annotations["kubernetes.io/ingress.class"]'

Actions against specific kind, based on condition. e.g. get pods with restarts > 10, delete them

pods=($(kubectl get pods -A | awk '{if($5>10)print $1","$2}' | sed 1d)) && for i in "${pods[@]}";do ns=$(echo $i | awk -F "," '{print $1}') && pod=$(echo $i | awk -F "," '{print $2}') && echo "Deleting:  NAMESPACE $ns"  POD $pod && kubectl -n $ns delete pod $pod && sleep 3;done

SSH

Run a local script with variables, as sudo on remote servers.

I. Create the script in a file commands.sh

e.g.

nc -v $1 22

II. Run the script against a list of servers.

USERNAME=<username>
MYCOMMAND=$(base64 commands.sh)

ips=($(get ips from somewhere| awk -F '|' '{print $5}' | grep -v "Private IP"))

for i in "${ips[@]}"
do
    ssh -i /path_to/.ssh/id_rsa -o StrictHostKeyChecking=no $USERNAME@$i " echo $MYCOMMAND | base64 -d | sudo bash "
done