Linux

Step 1 — Moving the MariaDB Data Directory mysql -u root -p select @@datadir; Output: +-----------------+ | @@datadir | +-----------------+ | /var/lib/mysql/ | +-----------------+ 1 row in set (0.00 sec) exit sudo systemctl stop mariadb sudo systemctl status mariadb Output: mysql systemd[1]: Stopped MariaDB database server. sudo rsync -av /var/lib/mysql /mnt/my-volume-01 sudo mv /var/lib/mysql /var/lib/mysql.bak Step 2 — Pointing to the New Data Location sudo vi /etc/my.cnf [mysqld] . . ....

If you need to sync the clock on Linux using the central NTP clock service, you can do the following: sudo service ntp stop sudo ntpd -gq sudo service ntp start The -gg flags do the following: Tell g flag tells the NTP Daemon to correct the time regardless of the offset The q flag tells it to exit immediately after setting the time

If using the EC2 launch type, the allowable network mode depends on the underlying EC2 instance’s operating system. If Linux, awsvpc, bridge, host and none mode can be used. If Windows, only the NAT mode is allowed. If using the Fargate launch type, the ‘awsvpc’ is the only network mode supported. Amazon ECS task networking The networking behavior of Amazon ECS tasks hosted on Amazon EC2 instances is dependent on the network mode defined in the task definition....

Summary This guide showcases the ability to use imported certificates from a third party provider (e.g. Venafi) in ACM, mount them in EFS and use them as trusted sources on Envoy sidecars with applications running in ECS. AppMesh is used as a passthrough with TLS termination occurring on the application container layer. Prerequisites and limitations Prerequisites A certificate that contains the chain of domains required for the fronted service and micro-services needed....

If you need to check if a volume is mounted in a Bash script, then you can do the following. How to Check Mounted Volumes First we need to determine the command that will be able to check. This can be done with the /proc/mounts path. How to Check if a Volume is Mounted in Bash if grep -qs '/mnt/foo ' /proc/mounts; then echo "It's mounted." else echo "It's not mounted....

If you need to check if a bash variable is empty, or unset, then you can use the following code: if [ -z "${VAR}" ]; The above code will check if a variable called VAR is set, or empty. What does this mean? Unset means that the variable has not been set. Empty means that the variable is set with an empty value of "". What is the inverse of -z?...

If you use the du command to list all the file sizes on Linux: du # or du -h # Human readable Then you would have noticed that they are not ordered by file size. Instead you can pass that result to the sort command as follows: du -h | sort -h

If you need to resize an EBS volume in AWS, you can do so using bash. Step 1 – Create a bash file Create a bash file called resize.sh: #!/bin/bash SIZE=${1:-20} INSTANCEID=$(curl http://169.254.169.254/latest/meta-data/instance-id) REGION=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone | sed 's/\(.*\)[a-z]/\1/') VOLUMEID=$(aws ec2 describe-instances \ --instance-id $INSTANCEID \ --query "Reservations[0].Instances[0].BlockDeviceMappings[0].Ebs.VolumeId" \ --output text \ --region $REGION) aws ec2 modify-volume --volume-id $VOLUMEID --size $SIZE while [ \ "$(aws ec2 describe-volumes-modifications \ --volume-id $VOLUMEID \ --filters Name=modification-state,Values="optimizing","completed" \ --query "length(VolumesModifications)"\ --output text)" !...

If you need to count how many files are in a directory on Linux, then you can use a combination of the ls command to list all the files, and the wc command to count how many lines are printed: Option 1 – Using wc ls | wc -l You can specify a directory as follows: ls <directory> | wc -l Option 2 – Using find You can count files recursively by using the find command:...

If you need to get the CPU Frequency in Linux, then you can run the following command: watch -n.1 "grep \"^[c]pu MHz\" /proc/cpuinfo"