# DevOps learning topics

###### tags: `DevOps`

## AWS
* Stack
* Region & Subnet
-> subnet mask
-> reference: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-sub.html
-> reference: https://www.calculator.net/ip-subnet-calculator.html
* AWS VPC(Amazon Virtual Private Cloud)
-> one region multi subnet?
* CloudFormation
* CIDR(Classless Inter-Domain Routing) cloudformation
-> reference: https://docs.aws.amazon.com/vpc/latest/userguide/configure-your-vpc.html
-> https://nordvpn.com/zh-tw/blog/ziwanglu-zhezhao/
-> https://docs.aws.amazon.com/vpc/latest/userguide/configure-subnets.html
> There are tools available on the internet to help you calculate and create IPv4 subnet CIDR blocks. You can find tools that suit your needs by searching for terms such as '**subnet calculator**' or '**CIDR calculator**'. Your network engineering group can also help you determine the CIDR blocks to specify for your subnets.
-> https://youtu.be/s_Ntt6eTn94
-> 虛擬IP?
* Bastion Host
-> 跳板機? between public subnet and private subnet
-> reference: https://dev.to/sergiodn/deploying-a-bastion-host-in-aws-using-cloudformation-k9c
-> reference: https://aws.amazon.com/tw/solutions/implementations/linux-bastion/
-> imageId在不同region會不一樣，還會隨時間更新
-> SSH agent reference: https://www.ssh.com/academy/ssh/agent
-> SSH agent reference: https://blog.gtwang.org/linux/using-ssh-agent-forwarding-to-avoid-being-asked-passphrase/
* IAM
-> instance profile reference (EN): https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_use_switch-role-ec2_instance-profiles.html
-> instance profile reference (CN): https://docs.aws.amazon.com/zh_tw/IAM/latest/UserGuide/id_roles_use_switch-role-ec2_instance-profiles.html
-> Users vs. Roles reference: https://stackoverflow.com/questions/46199680/difference-between-iam-role-and-iam-user-in-aws
* AWS RDS(Amazon Relational Database Service)
* LoadBalancer
-> listener port (向用戶端) vs. target group port (對instance)
* CloudWatch
* S3 Bucket
* AWS ACM(AWS Certificate Manager)
-> 下載SSL憑證，證明擁有這個domain
* CloudFront
-> OAI vs OAC reference: https://docs.aws.amazon.com/zh_tw/AmazonCloudFront/latest/DeveloperGuide/private-content-restricting-access-to-s3.html
* AWS Lambda
* AWS CLA(command lint interface)
* AWS ECR(Amazon Elastic Container Registry)
* AWS EC2(Amazon Elastic Compute Cloud)
-> 不同種類的instance，指令不一樣

## docker
* multi-stages builds
-> reference: https://docs.docker.com/build/building/multi-stage/
* docker-compose

## nginx
## SSH command
## YAML
## Jenkins
## vim
## DNS
* CNAME (Canonical Name Record)