My Code and Command line Snippets

AWS

Install AWS CLI

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#!/bin/bash
curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
unzip awscliv2.zip
sudo ./aws/install

Enable DHCP via userdata on Windows

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<powershell>
$NICs = Get-WMIObject Win32_NetworkAdapterConfiguration | where{$_.IPEnabled -eq "TRUE"}
Foreach($NIC in $NICs) { 
$NIC.EnableDHCP() 
$NIC.SetDNSServerSearchOrder() 
}
</powershell>

List unattached security groups

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export AWS_DEFAULT_PROFILE="$AWS_PROFILE"
export AWS_DEFAULT_REGION="$AWS_REGION"
awless inspect -i port_scanner --local | grep 'applying on nothing' | awk '{print $2}' | while read line; do
    aws ec2 describe-security-groups \
        --group-ids $line \
        --output text \
        --query 'SecurityGroups[].[GroupId, VpcId, GroupName]'
done | tr -s '\t' ',' | sort -t, -k2 -k3

List of Instances behind NAT Gateway

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export AWS_DEFAULT_OUTPUT="text"
aws ec2 describe-route-tables \
    --query 'RouteTables[?Routes[?NatGatewayId==`<NAT_GATEWAY_ID>`]].Associations[].SubnetId' | tr -s '\t' '\n' | while read line; do
    aws ec2 describe-instances \
        --query 'Reservations[].Instances[?SubnetId==`'"$line"'`].PrivateIpAddress' | tr -s '\t' '\n'
done

Fetch S3 Bucket Sizes

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aws s3 ls | awk '{print $NF}' | while read line; do
    echo "$line"
    aws s3 ls s3://"$line" --recursive | grep -v -E "(Bucket: |Prefix: |LastWriteTime|^$|--)" | awk 'BEGIN {total=0}{total+=$3}END{print total/1024/1024" MB"}'
done | paste -d, - -

Check images in launch configuration

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#!/bin/bash
echo "LaunchConfig,ImageId,CreationDate"
export AWS_DEFAULT_PROFILE="$AWS_PROFILE"
export AWS_DEFAULT_REGION="$AWS_REGION"
export AWS_DEFAULT_OUTPUT="text"
aws autoscaling describe-auto-scaling-groups --query 'AutoScalingGroups[].LaunchConfigurationName'  | tr -s '\t' '\n' | while read LAUNCHCONFIG; do
    aws autoscaling describe-launch-configurations --launch-configuration-names "$LAUNCHCONFIG" --query 'LaunchConfigurations[].ImageId' | while read AMI_ID; do
        export IMAGE_DETAILS="$(aws ec2 describe-images --image-ids "$AMI_ID" --query 'Images[].[ImageId,CreationDate]' | tr -s '\t' ',')"
        if [ -n "$IMAGE_DETAILS" ]; then
            echo "$LAUNCHCONFIG,$IMAGE_DETAILS"
        else
            echo "$LAUNCHCONFIG,N/A,N/A"
        fi
    done
done

List of instances without Environment tag

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aws ec2 describe-instances --query 'Reservations[].Instances[?!not_null(Tags[?Key == `Environment`].Value)] | [].[InstanceId]'

Get Instance metric

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aws cloudwatch get-metric-statistics \
    --metric-name CPUUtilization \
    --start-time 2019-01-01T00:00:00 \
    --end-time 2019-01-15T00:00:00 \
    --period 1209600 \
    --statistics Average \
    --namespace AWS/EC2 \
    --output text \
    --dimensions Name=InstanceId,Value=<INSTANCE_ID> \
    --query 'Datapoints[].Average'

IAM Role last used

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export AWS_DEFAULT_OUTPUT=text
aws iam list-roles --query 'Roles[].Arn' | tr -s '\t' '\n' | while read ROLE_ARN; do
    export NEW_ARN="$(echo $ROLE_ARN | awk -F/ '{print $NF}')"
    export ARN_JOB_ID="$(aws iam generate-service-last-accessed-details --arn $ROLE_ARN)"
    aws iam get-service-last-accessed-details --job-id "$ARN_JOB_ID" --query 'ServicesLastAccessed[].[ServiceName, LastAuthenticated]' | tr -s '\t' ',' | sed -e 's/^/,/g' -e 's,^,'"$NEW_ARN"',g'
done

Check if AMI is being used

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awless list images --sort created --reverse --columns id,name,created --format csv | grep years | cut -d, -f1 | while read line; do
    echo "$line"
    export AMI_ID="$line"
    aws ec2 describe-instances --query 'Reservations[].Instances[?ImageId==`'"$AMI_ID"'`].InstanceId' --output text | tr -s '\t' '\n'
    aws autoscaling describe-launch-configurations --output json --output text --query 'LaunchConfigurations[?ImageId==`'"$AMI_ID"'`]'
done

Unused Launch Configurations

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aws autoscaling describe-launch-configurations --output text --query 'LaunchConfigurations[].LaunchConfigurationName' | tr -s '\t' '\n' | sort | uniq | grep -v -f <(aws autoscaling describe-auto-scaling-groups --output text --query 'AutoScalingGroups[].LaunchConfigurationName' | tr -s '\t' '\n' | sort | uniq)

Find orphaned snapshots

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aws ec2 describe-snapshots --owner-ids self --output text --query 'Snapshots[].SnapshotId' | tr -s '\t' '\n' | sort | grep -v -f <(aws ec2 describe-images --owners self --output text --query 'Images[].BlockDeviceMappings[].Ebs.SnapshotId' | tr -s '\t' '\n' | sort)

Change backup and maintenance window of RDS

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export RDS_IDENT="$RDS_NAME"

aws rds modify-db-instance \
    --db-instance-identifier "$RDS_IDENT" \
    --backup-retention-period 7 \
    --preferred-backup-window 21:00-22:00 \
    --preferred-maintenance-window wed:22:00-wed:23:00 \
    --apply-immediately

Delete insufficient CloudWatch alarms

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awless list alarms --filter state=insufficient --filter name="<ALARM_PATTERN>" --format csv --columns name,state --no-headers | cut -d, -f1 | while read line; do
    echo "$line"
    awless delete alarm name=\"$line\" -f --no-sync & sleep 1
done

Empty Target Groups

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aws elbv2 describe-target-groups --output text --query 'TargetGroups[].TargetGroupArn' | tr -s '\t' '\n' | while read line; do
    echo $line
    export INST="$(aws elbv2 describe-target-health --target-group-arn "$line" --query 'TargetHealthDescriptions[].Target.Id')"
    if [ ${#line} -ne 0 ]; then
        echo "$INST"
    else
        echo None
    fi
done | paste -d, - -

List all Regions and AZs

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aws ec2 describe-regions | jq -r '.Regions[].RegionName' | while read REGION; do
    echo "$REGION"
    aws ec2 describe-availability-zones --region "$REGION" --output json | jq -r '.AvailabilityZones[].ZoneName' | paste -s -d, -
done

Apache HTTP to HTTPS redirection for ELB

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<IfModule mod_rewrite.c>
Options -Indexes
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [NE,L,R=301]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php [L]
</IfModule>
<FilesMatch "\.(js|woff|woff2|ttf)$">
	<IfModule mod_headers.c>
	    Header set Access-Control-Allow-Origin "*"
	</IfModule>
</FilesMatch>

GCP

List Unused Service Accounts

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gcloud recommender insights list \
  --insight-type=google.iam.serviceAccount.Insight \
  --location=global --filter=insightSubtype=SERVICE_ACCOUNT_USAGE \
  --project <PROJECT_ID> --format=json | jq -r '.[]|select(.content.lastAuthenticatedTime == null)|.content.email, .lastRefreshTime' | paste -d, - - | sort -t, -k1 -k2

Disabled/Delete Unused Service Accounts

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gcloud recommender insights list \
  --insight-type=google.iam.serviceAccount.Insight \
  --location=global --filter=insightSubtype=SERVICE_ACCOUNT_USAGE \
  --project <PROJECT_ID> --format=json | jq -r '.[]|select(.content.lastAuthenticatedTime == null)|.content.email' | sort | while read line; do
    echo "$line"
    gcloud --project <PROJECT_ID> iam service-accounts disable "$line"
  done

Linux

Add admin user in Wordpress using MySQL command line

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INSERT INTO `wp_users` (`user_login`, `user_pass`, `user_nicename`, `user_email`, `user_status`) VALUES ('ccvarun', MD5('ccvarun#123'), 'firstname lastname', 'varun@vrnchndk.in', '0');
INSERT INTO `wp_usermeta` (`umeta_id`, `user_id`, `meta_key`, `meta_value`) VALUES (NULL, (Select max(id) FROM wp_users), 'wp_capabilities', 'a:1:{s:13:"administrator";s:1:"1";}');
INSERT INTO `wp_usermeta` (`umeta_id`, `user_id`, `meta_key`, `meta_value`) VALUES (NULL, (Select max(id) FROM wp_users), 'wp_user_level', '10');

Generate SSL Cert local using certbot

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certbot certonly \
  --manual \
  --preferred-challenges dns \
  -d subdomain.example.com \
  -m email@example.com \
  --agree-tos \
  --config-dir "$PWD" \
  --work-dir "$PWD" \
  --logs-dir "$PWD"

Epoch Time to Date

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date -d @1560488400 +"%a, %d %b %Y %T %Z"

Get database sizes in MySQL

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SELECT table_schema AS "Database", 
ROUND(SUM(data_length + index_length) / 1024 / 1024 / 1024, 2) AS "Size (GB)" 
FROM information_schema.TABLES 
GROUP BY table_schema;

Get database sizes in PostgreSQL

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SELECT nspname || '.' || relname AS "relation",
    pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size"
  FROM pg_class C
  LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace)
  WHERE nspname NOT IN ('pg_catalog', 'information_schema')
    AND C.relkind <> 'i'
    AND nspname !~ '^pg_toast'
  ORDER BY pg_total_relation_size(C.oid) DESC
  LIMIT 20;

Last modified files in Linux

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find -L "$PATH" -type f -printf "%T@ %Tc %p\n" | sort -n

Get file path from script

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FILE_NAME="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )/$(basename $0)"
echo "$FILE_NAME"

Create Read Only Ubuntu User

https://gist.github.com/varunchandak/ea71fa2f025248aabc7893279dc12bec

DevOps

Delete build history in jenkins

  1. open https://<JENKINS_URL>/script
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    def jobName = "<ENTER_JOB_NAME>"
    def job = Jenkins.instance.getItem(jobName)  
    job.getBuilds().each { it.delete() }  
    job.nextBuildNumber = 1   
    job.save()

Random

Cut Youtube Video using ffmpeg

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ffmpeg -ss <starting_point> \
    -i "$(youtube-dl -g -f 22 <YOUTUBE_URL>)" \
    -t <how_much_time_after_starting_point> \
    -c copy <output>.mp4

Decrypt PDF on command line

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qpdf --decrypt --password=<PASSWORD> <PDF_PATH> decrypted-<PDF_PATH>

MacOS trackpad scrolling in vim+iTerm2

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defaults write com.googlecode.iterm2 AlternateMouseScroll -bool true

Split panaroma photos for Instagram uploads

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convert "IMG_0853.jpeg" -crop 33%x100% +repage +adjoin "output_%d.jpg"
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  1. AWS
    1. Install AWS CLI
    2. Enable DHCP via userdata on Windows
    3. List unattached security groups
    4. List of Instances behind NAT Gateway
    5. Fetch S3 Bucket Sizes
    6. Check images in launch configuration
    7. List of instances without Environment tag
    8. Get Instance metric
    9. IAM Role last used
    10. Check if AMI is being used
    11. Unused Launch Configurations
    12. Find orphaned snapshots
    13. Change backup and maintenance window of RDS
    14. Delete insufficient CloudWatch alarms
    15. Empty Target Groups
    16. List all Regions and AZs
    17. Apache HTTP to HTTPS redirection for ELB
  2. GCP
    1. List Unused Service Accounts
    2. Disabled/Delete Unused Service Accounts
  3. Linux
    1. Add admin user in Wordpress using MySQL command line
    2. Generate SSL Cert local using certbot
    3. Epoch Time to Date
    4. Get database sizes in MySQL
    5. Get database sizes in PostgreSQL
    6. Last modified files in Linux
    7. Get file path from script
    8. Create Read Only Ubuntu User
  4. DevOps
    1. Delete build history in jenkins
  5. Random
    1. Cut Youtube Video using ffmpeg
    2. Decrypt PDF on command line
    3. MacOS trackpad scrolling in vim+iTerm2
    4. Split panaroma photos for Instagram uploads
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