$ curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
$ unzip awscliv2.zip
$ sudo ./aws/install
$ which aws
/usr/local/bin/aws
$ aws --version
aws-cli/2.4.13 Python/3.8.8 Linux/4.18.0-348.2.1.el8_5.x86_64 exe/x86_64.rocky.8 prompt/o

$ aws configure
AWS Access Key ID [None]: ABCDEFGHIJKLMNOPQRST
AWS Secret Access Key [None]: 12345678901234/AAAAAAA/AAAAAAAAAEXAMPLEKEY
Default region name [None]: AA-BBB-1
Default output format [None]: json

$ aws rds start-db-instance --db-instance-identifier インスタンス名

$ aws rds stop-db-instance --db-instance-identifier インスタンス名

# rds describe-db-instances : RDSインスタンスの情報取得
# -cオプション : Using this option will result in more compact output by instead putting each JSON object on a single line.
# DBInstances配列からパイプして、DBInstanceIdentifierとDBInstanceStatusを取得する例
$ aws rds describe-db-instances | jq -c '.DBInstances[] | [.DBInstanceIdentifier, .DBInstanceStatus]'
["rdsxxx1","stopped"]
["rdsxxx2","stopped"]
["rdsxxx3","available"]

$ cat aws.txt | jq -c '.DBInstances[].DBInstanceStatus'
"stopped"
"stopped"
"available"

$ cat aws.txt | jq -r '.DBInstances[].DBInstanceIdentifier'
stopped
stopped
available

$ cat aws.txt | jq '.DBInstances[] | select(.DBInstanceStatus == "available") | {DB_Instance: .DBInstanceIdentifier, Status: .DBInstanceStatus}'
{
  "DB_Instance": "rdsxxx1,
  "Status": "available"
}

$ aws rds describe-db-log-files --db-instance-identifier DBインスタンス識別子 | jq .DescribeDBLogFiles[].LogFileName
"error/postgres.log"
"error/postgresql.log.2022-02-02-0816"
"error/postgresql.log.2022-02-02-0900"
"error/postgresql.log.2022-02-02-1000"
"error/postgresql.log.2022-02-02-1100"
"error/postgresql.log.2022-02-02-1200"
"error/postgresql.log.2022-02-02-1300"
.
.
.

aws rds download-db-log-file-portion --db-instance-identifier DBインスタンス識別子 --log-file-name error/postgres.log --output text
2022-02-02 08:16:23.017 GMT [6994] LOG:  skipping missing configuration file "/rdsdbdata/config/recovery.conf"
2022-02-02 08:16:23.017 GMT [6994] LOG:  skipping missing configuration file "/rdsdbdata/config/recovery.conf"
2022-02-02 08:16:23.017 GMT [6994] LOG:  skipping missing configuration file "/rdsdbdata/db/postgresql.auto.conf"
.
.
.

#!/bin/bash
( 
  if ! type aws > /dev/null 2>&1; then
    echo "aws cli is not installed."
    exit 1
  fi  

  if ! type jq > /dev/null 2>&1; then
    echo "jq is not installed."
    exit 1
  fi

  echo "InstanceId,Name,Status,PublicIP,PrivateIP,InstanceType,AvailabilityZone,LaunchTime"
  aws ec2 describe-instances | \
    jq -r '.[][].Instances[] | [.InstanceId,
                                [.Tags[] | select(.Key == "Name").Value][],
                                .State.Name, .PublicIpAddress,
                                .PrivateIpAddress,
                                .InstanceType,
                                .Placement.AvailabilityZone,
                                .LaunchTime] |@csv' | \
    sed -e 's/,,/,-,/g' -e 's/"//g'
) | column -s, -t

$ aws rds modify-db-cluster --db-cluster-identifier rdsname --master-user-password "12345678"

$ aws logs describe-log-groups | jq .logGroups[].logGroupName