Variables can contain letters, numbers and underscore, but must begin with a letter Can be stored as dictionaries which map keys to values. Dictionary variables can be refenced using bracket notation or dot notation, ex: dictionary_name [‘filed’] or dictionary.field Variables stored as a list (array) may be accessed by putting the element number in brackets:…
Ansible Error Handling
ignore_errors – Ignore any errors force_handlers – Force previously notified handler to run failed_when – Define failure conditions changed_when – Override the “changed” status result any_errors_fatal – Abort an entire play if any task fails block / rescue / always – Implement a block in order to logically group tasks and provide error handling
CentOS/RHEL 8 Boot Loader File
Grub Parameter File : /boot/grub2/grubenv # GRUB Environment Block saved_entry=82c1b57e69f343e28fe48516f70a9866-4.18.0-193.28.1.el8_2.x86_64 kernelopts=root=/dev/mapper/cl-root ro console=ttyS0,115200n8 no_timer_nvme_core.io_timeout=4294967295 nvme_core.max_retries=10 crashkernel=auto resume=/dev/mapper/cl-swap rd.lvm.lv=cl/root rd.lvm.lv=cl/swap boot_success=0 boot_indeterminate=0 ON BIOS (Basic Input/Output System) Systems : /boot/grub2/grub.cfg On Systems with UEFI (Unified Extensible Firmware Interface) : /boot/efi/EFI/centos/grub.cfg OR /boot/efi/EFI/rhel/grub.cfg To Generate Grub config file : grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg
Virtual Data Optimizer (VDO)
What – Virtual Data Optimizer (VDO) is a device mapper module which adds data reduction capabilities to the Linux block storage stack. VDO is a block virtualization technology that combines: Data Compression (Compress Remaining Blocks) Data Deduplication (Eliminate Duplicate Blocks) Thin provisioning (Eliminate Zero Blocks) Data Deduplication is a technique for eliminating duplicate copies of repeating…
Ansible and Core Components
There are several IT automations tools like Chef, Puppet, Salt, Rundeck etc. Ansible is one of them and its very popular. Same as other tools, it can configure systems, deploy software, and orchestrate more advanced IT tasks such as continuous deployments or zero downtime rolling updates etc. Ansible Tower by RedHat is a commercial (free…
AWS Tags
What A tag is a label (which contains key and value) assigned to an AWS resource. When AWS makes it easy to modify tags to meet your changing business requirements. Remember to include future plans for billing reports, automation and access control in your tagging Strategy. How You can create and edit tags using ”…
Amazon GuardDuty
Amazon GuardDuty is a threat detection service that enables you to monitor and protect your accounts and workloads. GuardDuty analyze events across AWS data sources, such as AWS CloudTrail event logs (Mgmt. and S3 data events) , Amazon VPC Flow Logs, and DNS log. It also uses integrated threat intelligence such as known malicious IP…
AWS Inspector
AWS Inspector is a Security vulnerability tool used to analyze the network visibility and security vulnerability of your EC2 instances and helps you to identify potential security issues Components: Assessment Targets Assessment Templates Assessment Run An assessment target represents a collection of AWS resources that help you accomplish your business goals, at present its available…
AWS Direct Connect
Why not we use VPN instead of Direct Connect AWS Site to Site VPN tunnels are only initiated from on-prem to AWS and traffic uses public Infrastructure and VPN use “out to internet” data transfer billing rates. The Single Virtual Private gateway is limited to a maximum of 1.25 Gbps for all VPN connections. Direct…
Connecting to AWS
AWS Provides various options to connect your On-premise/Office network to the Virtual Private Cloud (VPC). We can choose the right one for our business operations. Available Options are AWS Managed VPN Customer Managed Software VPN AWS Direct Connect AWS Direct Connect + VPN AWS VPN Cloud Hub Transit VPC AWS Managed VPN What AWS Managed…