https://github.com/fl64/snippets
https://github.com/fl64/snippets
bash snippets
Last synced: 23 days ago
JSON representation
- Host: GitHub
- URL: https://github.com/fl64/snippets
- Owner: fl64
- Created: 2022-01-24T14:39:01.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2023-04-23T15:40:24.000Z (about 3 years ago)
- Last Synced: 2025-03-12T01:55:06.428Z (about 1 year ago)
- Topics: bash, snippets
- Language: Shell
- Homepage:
- Size: 45.9 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# Snippets
## Testing
Useful services for testing online
- jq ployground https://jqplay.org/
- another jq ployground https://jqterm.com/?query=.
- go template https://repeatit.io/
- go https://goplay.space/
- k8s YAML generator https://k8syaml.com/
Upload from CLI
- https://bashupload.com/
- https://0x0.st/
- https://transfer.sh/
- https://hastebin.com/about.md
## CLI
### Bash
Redirect
```bash
# Redirect stderr to stdout
cmd 2>&1
# Redirect stdout to stderr
cmd 1>&2
## stderr and stdout to file
cmd 1>combined.log 2>&1
```
Show unix time 2 months ago
```bash
date +%s -d '2 months ago'
```
Show time in format YYYY-MM-DD-hh-mm-ss
```bash
date "+%F-%H-%M-%s"
```
find files accessed 5 min ago
```bash
find . -cmin -5
```
find logs for 2 days and tar it
```bash
find logs/ -mtime -2 -type f | xargs -d "\n" tar cvfz $(date "+%F-%H-%M-%S")-logs.tar.gz
```
find Revision: field in all y(a)ml files
```bash
find . -name '*.yml' -o -name '*.yaml' -print0 | xargs -0 grep 'Revision:' | grep -v depricated
```
find all catalogs with helm charts and lint them
```bash
find apps/ -mindepth 1 -maxdepth 1 -type d | xargs -I %HELMCHART% bash -c "helm dependency build %HELMCHART% && helm lint --with-subcharts --debug %HELMCHART%"
```
find | grep and check
```bash
find . -name '*.yml' -o -name '*.yaml' -print0 | xargs -0 grep -E '(R|r)evision: .+' | grep -vE '(depricated|HEAD)' || EXIT_CODE=$?
```
find and delete
```bash
find / -name .terraform -exec rm -rf {} \;
find . -name ".terraform" -print0 | xargs -I {} -0 rm -rf "{}"
```
loop over array vars with suffix
```bash
declare -A HTTP_CHECK_1=([addr]=google.com [port]=443)
declare -A HTTP_CHECK_2=([addr]=example.com [port]=383)
declare -A SIP_CHECK_1=([addr]=1.1.1.1 [port]=5060)
declare -A SIP_CHECK_2=([addr]=2.2.2.2 [port]=5060)
for _CHECK in $(compgen -v | grep -xE '(HTTP|SIP)_CHECK_.*'); do
declare -n p="$_CHECK"
echo "${p[addr]}"
done
```
read template into the var
```bash
read -r -d '' VAULT_CONF < >(tee >(logger -p local0.notice -t $(basename "$0")))
exec 2> >(tee >&2 >(logger -p local0.error -t $(basename "$0")))
```
wait for changes and do something (POST for example)
```bash
while true; do
inotifywait "$(readlink -f $1)"
echo "[$(date +%s)] Trigger refresh"
curl -sSL -X POST "$2" > /dev/null
done
```
read ssh keys from variables starting from 'SSHKEY\_'
```bash
for key in "${!SSHKEY_@}"; do
ssh-add <(echo "${!key}")
done
```
heredoc to var
```bash
read -r -d '' CONFIG < /dev/null && pwd )
```
script execution time
```bash
start=$(date +%s)
sleep 10
end=$(date +%s)
diffSeconds="$(($end-$start))"
diffTime=$(date -d @${diffSeconds} +"%H:%M:%S" -u)
echo "Diff in seconds: ${diffSeconds}."
echo "Diff time(H:M:S): ${diffTime}."
```
passing parameters to bash when executing a script fetched by curl
```bash
curl http://example.com/script.sh | bash -s -- arg1 arg2
```
### Ecnryption
Encrypt/decrypt file with AES
```bash
echo "secret" | openssl enc -aes-256-cbc -a -e -iter 1000 -k "password"
echo "U2FsdGVkX19qISwjfyH5M9eNCFnEh5XfUHBBA7yfNkQ=" | openssl enc -aes-256-cbc -a -d -iter 1000 -k "password"
```
### system
journalctl get docker logs
```bash
journalctl -u docker -o json | jq -cMr 'select(has("CONTAINER_ID") | not) | .MESSAGE'
```
boot
```bash
journalctl --list-boots
journalctl -b -1 #last boot
```
priority
```bash
journalctl -b -1 -p "emerg".."crit" # output all messages with priority between emergency and critical from last boot
journalctl -b -1 -p 0..2 the same
journalctl -p 4 # from error level error
```
time
```bash
journalctl -n 50 --since "1 hour ago" # last 50 messages logged within the last hour
journalctl --since "2015-06-26 23:15:00" --until "2015-06-26 23:20:00" # system time spec: https://www.freedesktop.org/software/systemd/man/systemd.time.html
```
reverse
```bash
journalctl -u docker -r # list in reverse order
```
### git
git diff to folder
```bash
git -C some/code/app diff --relative HEAD~ # relative path in patch file
git -C some/code/app diff HEAD~ > app.patch # full path
git apply app.patch
```
using oath2 token instead of password
```bash
git config --global url."https://oauth2:${TOKEN}@gitlab.com/".insteadOf https://gitlab.com/
```
create MR on gitlab
```bash
git push \
-o merge_request.create \
-o merge_request.target=master \
-o merge_request.title="switch to ${CI_COMMIT_TAG}" \
-o merge_request.description="${DESCRIPTION//$'\n'/
}" \
"https://oauth2:${TOKEN}@gitlab.com/${DEST_GROUP}/${DEST_REPO}.git" \
"${NEW_BRANCH}"
```
delete tag localy and remotely
```bash
git tag -d v1.0.0
git push origin :refs/tags/v1.0.0
```
delete tag localy and remotely v2
```bash
git push --delete origin v1.0.0
git tag -d v1.0.0
```
### networking
ssh ignore known hosts for vagrant
```bash
ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -i .vagrant/machines/test00/virtualbox/private_key vagrant@192.168.56.99
```
scan ssh keys
```bash
ssh-keyscan -p 2222 gitlab.example.ru
```
open remote server port on local machine
```bash
ssh -N -f -L :127.0.0.1:
```
check port verbosely
```bash
nc -vzw 2 server.example.com 8500
```
get ssl certificate from web
```bash
echo | openssl s_client -showcerts -servername 10.3.0.17 -connect 10.3.0.17:443 2>/dev/null | openssl x509 -inform pem -noout -text
```
curl via ip
```bash
curl https://example.com --resolve 'example.com:443:192.0.2.17'
```
curl and untar
```bash
sudo bash -c "curl -L https://github.com/cilium/cilium-cli/releases/download/v0.12.4/cilium-linux-amd64.tar.gz | tar -xz -C /usr/local/bin/"
```
send email with curl
```bash
curl --ssl-reqd \
--url 'smtps://smtp.gmail.com:465' \
--user 'username@gmail.com:password' \
--mail-from 'username@gmail.com' \
--mail-rcpt 'john@example.com' \
--upload-file /dev/null
```
get all TCP-packets with RST flag https://serverfault.com/questions/217605/how-to-capture-ack-or-syn-packets-by-tcpdump
```bash
tcpdump "tcp[tcpflags] & (tcp-rst) != 0"
tcpdump "(net 10.1.2.0/24 or 10.2.2.0/24) and tcp[tcpflags] & (tcp-rst) != 0"
```
find pattern in network traffic
```bash
ngrep -iq "/ping.*user-agent" "port 80" -W byline
```
### docker
remove all older than
```bash
docker system prune --filter 'until=168h' --all -f
```
docker image format
```bash
docker images --format "{{ .ID}} {{.Repository }}:{{ .Tag}}"
```
### k8s
git images
```bash
kubectl get pods --all-namespaces -o jsonpath="{.items[*].spec.containers[*].image}" |\
tr -s '[[:space:]]' '\n' |\
sort |\
uniq -c
```
k8s delete ns with finalizers
```bash
NAMESPACE=argocd-system
kubectl proxy &
kubectl get namespace $NAMESPACE -o json |jq '.spec = {"finalizers":[]}' >temp.json
curl -k -H "Content-Type: application/json" -X PUT --data-binary @temp.json 127.0.0.1:8001/api/v1/namespaces/$NAMESPACE/finalize
```
wait for some res
```bash
kubectl wait --for condition=ready -l node-role.kubernetes.io/control-plane node
kubectl wait --for condition=ready -l node-role.kubernetes.io/master node
kubectl wait --for condition=ready node --all --timeout=10s
kubectl wait --for=condition=ready pod -l app=someapp
kubectl wait --for=condition=complete --timeout=30s job/some-job
```
exec to some shell
```bash
kubectl exec -i -t -n default pt-test-pod -c test-pod "--" sh -c "clear; (bash || ash || sh)"
```
limits requests
```bash
kubectl get pods -o=custom-columns=NAME:spec.containers[*].name,MEMREQ:spec.containers[*].resources.requests.memory,MEMLIM:spec.containers[*].resources.limits.memory,CPUREQ:spec.containers[*].resources.requests.cpu,CPULIM:spec.containers[*].resources.limits.cpu
```
get cadvisor metrics
```bash
kubectl proxy --port 8888 & curl -s http://localhost:8888/api/v1/nodes/${NODE_NAME}/proxy/metrics/cadvisor
```
heredoc apply
```bash
cat < tf.state
vi tf.state # (don't forget increase serial)
terraform state push tf.state
```
## Jq
select records with .level is "info|error|warn" and .msg is not contain "deprecated"
```bash
jq '. | select(.level | test("info|error|warn")) | select(.msg | test(".+deprecated.+") | not )
```
select records with worker label exist and have addr type InternalIP
```bash
jq '.items[] | select(.metadata.labels."node-role.kubernetes.io/worker"!=null) | .status.addresses | .[] | select (.type=="InternalIP") | .address' -r
```
using args
```bash
jq --arg name "istiod-v1x13" '.items[] | .metadata | select( .name | test($name)) | .name' -r
jq --arg revision v1x13 '.items[] | select( .spec.revision == $revision ) | .metadata.name' -r
```