chore(aws): encrypt and decrypt with kms

knowledge base/cloud computing/aws/README.md

@@ -351,6 +351,7 @@ Examples:
 - [Rotating AWS KMS keys]
 - [Image baking in AWS using Packer and Image builder]
 - [Avoid the 60 minutes timeout when using the AWS CLI with IAM roles]
+- [Using AWS KMS via the CLI with a Symmetric Key]
 
 <!--
   Reference
@@ -419,4 +420,5 @@ Examples:
 [date & time policy conditions at aws - 1-minute iam lesson]: https://www.youtube.com/watch?v=4wpKP1HLEXg
 [image baking in aws using packer and image builder]: https://dev.to/santhoshnimmala/image-baking-in-aws-using-packer-and-image-builder-1ed3
 [introduction to aws iam assumerole]: https://aws.plainenglish.io/introduction-to-aws-iam-assumerole-fbef3ce8e90b
+[using aws kms via the cli with a symmetric key]: https://nsmith.net/aws-kms-cli
 [you might be clueless as to why aws assume role isn't working, despite being correctly set up]: https://medium.com/@kamal.maiti/you-might-be-clueless-as-to-why-aws-assume-role-isnt-working-despite-being-correctly-set-up-1b3138519c07

knowledge base/cloud computing/aws/cli.md

@@ -108,6 +108,21 @@ aws iam detach-user-policy --user-name 'me-user' \
 aws iam delete-user-policy --user-name 'me-user' --policy-name 'user-ro-access-bucket'
 
 
+# Create new symmetric keys.
+aws kms create-key
+
+# Encrypt text.
+aws kms encrypt --key-id '01234567-89ab-cdef-0123-456789abcdef' --plaintext 'My Test String'
+aws kms encrypt --key-id '01234567-89ab-cdef-0123-456789abcdef' --plaintext 'My Test String' \
+  --query 'CiphertextBlob' --output 'text' \
+| base64 --decode > 'ciphertext.dat'
+
+# Decrypt files.
+aws kms decrypt --ciphertext-blob 'fileb://ciphertext.dat'
+aws kms decrypt --ciphertext-blob 'fileb://ciphertext.dat' --query 'Plaintext' --output 'text' \
+| base64 --decode
+
+
 # List hosted zones.
 aws route53 list-hosted-zones
 
@@ -265,9 +280,11 @@ Solutions:
 - [Improved CLI auto-prompt mode]
 - [Install the Session Manager plugin for the AWS CLI]
 - [Use an IAM role in the AWS CLI]
+- [Using AWS KMS via the CLI with a Symmetric Key]
 
 <!--
-  References
+  Reference
+  ═╬═Time══
   -->
 
 <!-- Knowledge base -->
@@ -290,3 +307,4 @@ Solutions:
 [install the session manager plugin for the aws cli]: https://docs.aws.amazon.com/systems-manager/latest/userguide/install-plugin-macos-overview.html#install-plugin-macos-signed
 [quickstart]: https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-quickstart.html
 [use an iam role in the aws cli]: https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-role.html
+[using aws kms via the cli with a symmetric key]: https://nsmith.net/aws-kms-cli

knowledge base/cloud computing/aws/ebs.md

@@ -21,6 +21,11 @@ aws ec2 describe-volumes --output 'text' --filters 'Name=status,Values=available
 
 </details>
 
+Volumes can have their size **increased**, but **not** reduced.<br/>
+After increase, the filesystem **must** be [extended][Extend the file system after resizing an EBS volume] to take
+advantage of the change in size.<br/>
+Apparently, Linux machines are able to do that automatically with a reboot.
+
 ## Snapshots
 
 When created, snapshots are **incremental**.<br/>
@@ -45,6 +50,7 @@ take **up to 72h**.
 - [Archive Amazon EBS snapshots]
 - [Automate snapshot lifecycles]
 - [Choose the best Amazon EBS volume type for your self-managed database deployment]
+- [Extend the file system after resizing an EBS volume]
 
 ### Sources
 
@@ -52,6 +58,7 @@ take **up to 72h**.
 - [Delete Unused AWS EBS Volumes]
 - [`describe-volumes`][describe-volumes]
 - [`delete-volume`][delete-volume]
+- [How do I increase or decrease the size of my EBS volume?]
 
 <!--
   Reference
@@ -70,6 +77,8 @@ take **up to 72h**.
 [delete-volume]: https://docs.aws.amazon.com/cli/latest/reference/ec2/delete-volume.html
 [describe-volumes]: https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-volumes.html
 [documentation]: https://docs.aws.amazon.com/ebs/
+[extend the file system after resizing an ebs volume]: https://docs.aws.amazon.com/ebs/latest/userguide/recognize-expanded-volume-linux.html
+[how do i increase or decrease the size of my ebs volume?]: https://repost.aws/knowledge-center/ebs-increase-decrease-volume-size
 [what is block storage?]: https://aws.amazon.com/what-is/block-storage/
 
 <!-- Others -->