Create an AWS VPC and Subnet using the AWS CLI and Bash
3 min readSep 12, 2017
For those learning AWS/AWS CLI this is a quick document on how create an AWS VPC and Subnet using the AWS CLI (AWS Command Line Interface) from a Linux/Bash script.
The below bash script performs the following:
- adds a new VPC
- names the VPC
- adds dns support
- adds a dns hostname
- creates an internet gateway
- names the internet gateway
- creates the subnet
- names the subnet
- enables public ip on the subnet
- creates the security group for the subnet
- names the security group
- enables port 22 for ssh
- creates the route table
- names the route table
- adds route to the internet gateway
- adds the route table to the subnet
I am using the jq Command-line JSON processor to capture JSON output from each AWS CLI command. If using a RHEL/CentOS 7 jq is found in EPEL.
The private ip subnet will be created in the bash script and will be mapped to a public ip that is provided by AWS. After you build an AWS Linux instance with the vpc, subnet and security group you will be able to access the instance through:
ssh -i “yourPrivateKeyFile.pem” ec2-user@ec2-public-ip-address.compute-1.amazonaws.com
Here is the create-aws-vpc bash script:
#!/bin/bash
# create-aws-vpc#variables used in script:
availabilityZone="us-east-1a"
name="your VPC/network name"
vpcName="$name VPC"
subnetName="$name Subnet"
gatewayName="$name Gateway"
routeTableName="$name Route Table"
securityGroupName="$name Security Group"
vpcCidrBlock="10.0.0.0/16"
subNetCidrBlock="10.0.1.0/24"
port22CidrBlock="0.0.0.0/0"
destinationCidrBlock="0.0.0.0/0"echo "Creating VPC..."#create vpc with cidr block /16
aws_response=$(aws ec2 create-vpc \
--cidr-block "$vpcCidrBlock" \
--output json)
vpcId=$(echo -e "$aws_response" | /usr/bin/jq '.Vpc.VpcId' | tr -d '"')#name the vpc
aws ec2 create-tags \
--resources "$vpcId" \
--tags Key=Name,Value="$vpcName"#add dns support
modify_response=$(aws ec2 modify-vpc-attribute \
--vpc-id "$vpcId" \
--enable-dns-support "{\"Value\":true}")#add dns hostnames
modify_response=$(aws ec2 modify-vpc-attribute \
--vpc-id "$vpcId" \
--enable-dns-hostnames "{\"Value\":true}")#create internet gateway
gateway_response=$(aws ec2 create-internet-gateway \
--output json)
gatewayId=$(echo -e "$gateway_response" | /usr/bin/jq '.InternetGateway.InternetGatewayId' | tr -d '"')#name the internet gateway
aws ec2 create-tags \
--resources "$gatewayId" \
--tags Key=Name,Value="$gatewayName"#attach gateway to vpc
attach_response=$(aws ec2 attach-internet-gateway \
--internet-gateway-id "$gatewayId" \
--vpc-id "$vpcId")#create subnet for vpc with /24 cidr block
subnet_response=$(aws ec2 create-subnet \
--cidr-block "$subNetCidrBlock" \
--availability-zone "$availabilityZone" \
--vpc-id "$vpcId" \
--output json)
subnetId=$(echo -e "$subnet_response" | /usr/bin/jq '.Subnet.SubnetId' | tr -d '"')#name the subnet
aws ec2 create-tags \
--resources "$subnetId" \
--tags Key=Name,Value="$subnetName"#enable public ip on subnet
modify_response=$(aws ec2 modify-subnet-attribute \
--subnet-id "$subnetId" \
--map-public-ip-on-launch)#create security group
security_response=$(aws ec2 create-security-group \
--group-name "$securityGroupName" \
--description "Private: $securityGroupName" \
--vpc-id "$vpcId" --output json)
groupId=$(echo -e "$security_response" | /usr/bin/jq '.GroupId' | tr -d '"')#name the security group
aws ec2 create-tags \
--resources "$groupId" \
--tags Key=Name,Value="$securityGroupName"#enable port 22
security_response2=$(aws ec2 authorize-security-group-ingress \
--group-id "$groupId" \
--protocol tcp --port 22 \
--cidr "$port22CidrBlock")#create route table for vpc
route_table_response=$(aws ec2 create-route-table \
--vpc-id "$vpcId" \
--output json)
routeTableId=$(echo -e "$route_table_response" | /usr/bin/jq '.RouteTable.RouteTableId' | tr -d '"')#name the route table
aws ec2 create-tags \
--resources "$routeTableId" \
--tags Key=Name,Value="$routeTableName"#add route for the internet gateway
route_response=$(aws ec2 create-route \
--route-table-id "$routeTableId" \
--destination-cidr-block "$destinationCidrBlock" \
--gateway-id "$gatewayId")#add route to subnet
associate_response=$(aws ec2 associate-route-table \
--subnet-id "$subnetId" \
--route-table-id "$routeTableId")echo " "
echo "VPC created:"
echo "Use subnet id $subnetId and security group id $groupId"
echo "To create your AWS instances"# end of create-aws-vpc
