Oneliners and code snippets

oneliners.md

• List EC2 Instances:

function li() {
  aws ec2 describe-instances \
    | jq -r '.Reservations[].Instances[] | [(.Tags[]|select(.Key=="Name").Value),.InstanceId,.PrivateIpAddress,.VpcId,.State.Name,.LaunchTime] | @csv' \
    | mlr --c2p --implicit-csv-header label Nmae,InstanceId,PrivateIpAddress,VpcId,State,LaunchTime then sort -f LaunchTime then cat
  }

function li() {
  aws ec2 describe-instances                                            \
    $([[ -n ${instance_ids} ]] && echo --instance-ids ${instance_ids})  \
    --query "
      Reservations[].Instances[][
        InstanceId,
        InstanceType,
        State.Name,
        [Tags[?Key=='Name'].Value][0][0],
        PublicIpAddress,
        PrivateIpAddress,
        Placement.AvailabilityZone,
        VpcId
      ]"                                                               \
    --output text       |
  grep -E -- "$filters" |
  sort -k 4,4 |
  align
}

---

• Port forward over AWS SSM:

aws ssm start-session --target $INSTANCE_ID \
 --document-name AWS-StartPortForwardingSession \
 --parameters '{"portNumber":["80"],"localPortNumber":["9999"]}'

---

• Convert video container type:

ffmpeg -i input.mkv -acodec copy -vcodec copy -f mp4 output.mp4

---

• Create gif from video:

ffmpeg -ss 61.0 -t 2.5 -i StickAround.mp4 -filter_complex \
"[0:v] fps=12,scale=480:-1,split [a][b];[a] palettegen [p];[b][p] paletteuse" SmallerStickAround.gif

---

• Show git commit of current Nix channel:

 nix-instantiate --eval -E '(import <unstable> {}).lib.version'

---

• List all resources used by a security group:

aws ec2 describe-network-interfaces --filters Name=group-id,Values=<group-id> --region <region> --output json

---

• List all security groups used by all Lambas:

aws lambda list-functions | jq -c '.Functions[] | {FunctionArn, SecurityGroups: (.VpcConfig.SecurityGroupIds[]? // null) }'

---

• Find what owns an unknown IP address in AWS account:

aws ec2 describe-network-interfaces --filters "Name=addresses.private-ip-address,Values=ip.add.re.ss"

---

• Monitor port for any listening applications

sudo lsof -r 1 -sTCP:LISTEN -i:443

---

• List all AWS Secrets as Markdown

aws secretsmanager list-secrets | \
  jq -r '.SecretList[] | [.Name, .ARN, .Description] | @csv' | \
  mlr --icsv --omd label Secret,ARN,Description then sort -f Secret

---

• Find summary time of all videos

find . -type f -exec mediainfo --Inform="General;%Duration%" "{}" \; 2>/dev/null \
  | awk '{s+=$1/1000} END {h=s/3600; s=s%3600; printf "%.2d:%.2d\n", int(h), int(s/60)}'

---

• Shrink GIF Size:

https://stackoverflow.com/questions/23008104/how-to-compress-the-image-using-gifsicle-tool-or-any-other-tool-on-ubuntu

gifsicle -O3 --lossy=80 gifimage1.gif -o new-gifimage1.gif

---

• Multiline grep with ripgrep:

https://til.hashrocket.com/posts/9zneks2cbv-multiline-matches-with-ripgrep-rg

rg --multiline "(?s)aws_s3_bucket.*bucket-name-here"

---

• List only file resolution with ffprobe:

 ffprobe -v error -select_streams v:0 -show_entries format=filename:stream=width,height,avg_frame_rate -of csv=p=0 file.mp4

find . -type f \( -iname '*.wmv' -o -iname '*.mp4' -o -iname '*.avi' -o -iname '*.mkv' -o -iname '*.mov' -o -iname '*.mpg' \) \
 -exec ffprobe -v error -select_streams v:0 -show_entries format=filename:stream=width,height,avg_frame_rate \
 -of csv=p=0 {} -print_format json \; | \
 mlr --json --opprint flatten then cut -x -f programs then rename \
 streams.1.width,width,streams.1.height,height,streams.1.avg_frame_rate,framerate,format.filename,filename \
 then sort -f filename \
 then put '$framerate = splita($framerate, "/"); $framerate = $framerate[1] / $framerate[2]; $framerate = fmtnum($framerate, "%.2f")'

---

• Rsync only file timestamps from remote host:

rsync -vrti --size-only --existing src:/a /a

---

• Open file in Windows from WSL:

cmd.exe /C start <file>

---

• Find latest CentOS 6 /7 AMIs on the marketplace:

# CentOS 6

aws --region us-east-1 ec2 describe-images \
    --owners 'aws-marketplace' \
    --filters 'Name=product-code,Values=6x5jmcajty9edm3f211pqjfn2' \
    --query 'sort_by(Images, &CreationDate)[-1].[ImageId]' \
    --output 'text'
    
# CentOS 7

aws --region us-east-1 ec2 describe-images \
    --owners 'aws-marketplace' \
    --filters 'Name=product-code,Values=aw0evgkw8e5c1q413zgy5pjce' \
    --query 'sort_by(Images, &CreationDate)[-1].[ImageId]' \
    --output 'text'

---

• Add AWS security group rule with description:

aws ec2 authorize-security-group-ingress --group-id sg-XXX \
  --ip-permissions \
  'FromPort=443,ToPort=443,IpProtocol=tcp,IpRanges=[{CidrIp="6.6.6.6/32",Description="group test name here"}]'

---

• Read multiple lines in bash

$ while read -r FILE; do
> read -r VERSION
> echo "file: $FILE VERSION: $VERSION"
> done < out

---

• Install helm chart without tiller:

helm template --namespace <namespace> --name <name> . -f values.yml | kubectl apply -f -

---

• Mass delete s3 keys:

cat file-of-keys | xargs -P8 -n1000 bash -c 'aws s3api delete-objects --bucket MY_BUCKET_NAME \
  --delete "Objects=[$(printf "{Key=%s}," "$@")],Quiet=true"' _

---

• Run AWS ssm command on remote host:

aws ssm send-command --instance-ids "i-ID" --document-name  "AWS-RunShellScript" \
  --parameters commands='find / -ls' \ 
  --output-s3-bucket-name s3-bucket-name

---

• Find largest git objects in repository:

git rev-list --objects --all \
| git cat-file --batch-check='%(objecttype) %(objectname) %(objectsize) %(rest)' \
| sed -n 's/^blob //p' \
| sort --numeric-sort --key=2 \
| cut -c 1-12,41- \
| $(command -v gnumfmt || echo numfmt) --field=2 --to=iec-i --suffix=B --padding=7 --round=nearest

---

• Split input into files based on field name:

awk -F: '{print > $4 ".txt" }' /etc/passwd

---

• Rename files with parallel

 find . -type f -name '*.mkv'| parallel mv -i {} {//}/{//}.mkv

---

• Launch AWS instance with awless:

awless create instance distro=canonical:ubuntu  type=t2.medium keypair=keyname subnet=@subnet-name name=instance-name

---

• Edit chef data bag locally

knife solo data bag edit credentials passwords \
  --secret-file test/integration/data_bags/encrypted_data_bag_secret --data-bag-path test/integration/data_bags

---

• Delete until fourth field. Useful when 4th field item has spaces.

awk '{print substr($0, index($0, $4))}'

---

• Replace newlines with \n:

sed -E ':a;N;$!ba;s/\r{0,1}\n/\\n/g' file

---

• Replace newlines with '\n' in Ruby:

ruby -e 'p ARGF.read' file

---

• Tcpdump to watch nicely formatted HTTP requests with headers coming in via network to the local server

sudo stdbuf -oL -eL /usr/sbin/tcpdump -A -s 10240 "tcp port 80 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)" | egrep -a --line-buffered ".+(GET |HTTP\/|POST )|^[A-Za-z0-9-]+: " | perl -nle 'BEGIN{$|=1} { s/.*?(GET |HTTP\/[0-9.]* |POST )/\n$1/g; print }'

---

• Show SSL Certificate

echo | openssl s_client -showcerts -servername host.com \
  -connect host:443 2>/dev/null | openssl x509 -inform pem -noout -text

---

• Show SSL Expiration Date

echo | openssl s_client -showcerts -servername host.com \
  -connect host:443 2>/dev/null | openssl x509 -inform pem -noout -dates

---

• Delete old snaps

$ echo snap list --all | while read snapname ver rev trk pub notes; do if [[ $notes = *disabled* ]]; then snap remove "$snapname" --revision="$rev"; fi; done