Onboarding : Azure Configure NSG, ASG, Firewall, and Service Endpoints

# Define variable
rg=<resource group name>

# create a resource group
az group create --name $rg --location <location>

# Create a virtual network and subnet for application servers and database servers
az network vnet create \
    --resource-group $rg \
    --name ERP-servers \
    --address-prefix 10.0.0.0/16 \
    --subnet-name Applications \
    --subnet-prefix 10.0.0.0/24

az network vnet subnet create \
    --resource-group $rg \
    --vnet-name ERP-servers \
    --address-prefix 10.0.1.0/24 \
    --name Databases

# Create Network Security Group
az network nsg create \
    --resource-group $rg \
    --name ERP-SERVERS-NSG

# Create virtual machines running Ubuntu (build the AppServer virtual machine)
# NSG is assigned to NIC of the VM
wget -N https://raw.githubusercontent.com/MicrosoftDocs/mslearn-secure-and-isolate-with-nsg-and-service-endpoints/master/cloud-init.yml && \
az vm create \
    --resource-group $rg \
    --name AppServer \
    --vnet-name ERP-servers \
    --subnet Applications \
    --nsg ERP-SERVERS-NSG \
    --image UbuntuLTS \
    --size Standard_DS1_v2 \
    --admin-username azureuser \
    --custom-data cloud-init.yml \
    --no-wait \
    --admin-password <password>

# build the DataServer virtual machine
az vm create \
    --resource-group $rg \
    --name DataServer \
    --vnet-name ERP-servers \
    --subnet Databases \
    --nsg ERP-SERVERS-NSG \
    --size Standard_DS1_v2 \
    --image UbuntuLTS \
    --admin-username azureuser \
    --custom-data cloud-init.yml \
    --admin-password <password>

# To confirm that the virtual machines are running
az vm list \
    --resource-group $rg \
    --show-details \
    --query "[*].{Name:name, Provisioned:provisioningState, Power:powerState}" \
    --output table

# To connect to your virtual machines, use SSH directly from Cloud Shell. To do this, you need the public IP addresses that have been assigned to your virtual machines
az vm list \
    --resource-group $rg \
    --show-details \
    --query "[*].{Name:name, PrivateIP:privateIps, PublicIP:publicIps}" \
    --output table

# To make it easier to connect to your virtual machines during the rest of this exercise, assign the public IP addresses to variables
APPSERVERIP="$(az vm list-ip-addresses \
                 --resource-group $rg \
                 --name AppServer \
                 --query "[].virtualMachine.network.publicIpAddresses[*].ipAddress" \
                 --output tsv)"

DATASERVERIP="$(az vm list-ip-addresses \
                 --resource-group $rg \
                 --name DataServer \
                 --query "[].virtualMachine.network.publicIpAddresses[*].ipAddress" \
                 --output tsv)"

# to check whether you can connect to your AppServer virtual machine
ssh azureuser@$APPSERVERIP -o ConnectTimeout=5
# You'll get a Connection timed out message.

# to check whether you can connect to your DataServer virtual machine
ssh azureuser@$DATASERVERIP -o ConnectTimeout=5
# You'll get the same connection failure message.

# Create a security rule for SSH
az network nsg rule create \
    --resource-group $rg \
    --nsg-name ERP-SERVERS-NSG \
    --name AllowSSHRule \
    --direction Inbound \
    --priority 100 \
    --source-address-prefixes '*' \
    --source-port-ranges '*' \
    --destination-address-prefixes '*' \
    --destination-port-ranges 22 \
    --access Allow \
    --protocol Tcp \
    --description "Allow inbound SSH"

# check whether you can now connect to your AppServer virtual machine
ssh azureuser@$APPSERVERIP -o ConnectTimeout=5

ssh azureuser@$DATASERVERIP -o ConnectTimeout=5

# You will be asked "are you sure to continue?", you answer with yes, and enter password
# for exit enter exit

# Now add a rule so that AppServer can communicate with DataServer over HTTP, but DataServer can't communicate with AppServer over HTTP
az network nsg rule create \
    --resource-group $rg \
    --nsg-name ERP-SERVERS-NSG \
    --name httpRule \
    --direction Inbound \
    --priority 150 \
    --source-address-prefixes 10.0.1.4 \
    --source-port-ranges '*' \
    --destination-address-prefixes 10.0.0.4 \
    --destination-port-ranges 80 \
    --access Deny \
    --protocol Tcp \
    --description "Deny from DataServer to AppServer on port 80"

# to connect to your AppServer virtual machine, and check if AppServer can communicate with DataServer over HTTP.
ssh -t azureuser@$APPSERVERIP 'wget http://10.0.1.4; exit; bash'
# he response should include a 200 OK message.

# to connect to your DataServer virtual machine, and check if DataServer can communicate with AppServer over HTTP
ssh -t azureuser@$DATASERVERIP 'wget http://10.0.0.4; exit; bash'
# his shouldn't succeed, because you've blocked access over port 80. Press Ctrl+C to stop the command prior to the timeout.

# create a new application security group called ERP-DB-SERVERS-ASG
az network asg create \
    --resource-group $rg \
    --name ERP-DB-SERVERS-ASG

# to associate DataServer with the application security group
az network nic ip-config update \
    --resource-group $rg \
    --application-security-groups ERP-DB-SERVERS-ASG \
    --name ipconfigDataServer \
    --nic-name DataServerVMNic \
    --vnet-name ERP-servers \
    --subnet Databases

# to update the HTTP rule in the ERP-SERVERS-NSG network security group. It should reference the ERP-DB-Servers application security group
az network nsg rule update \
    --resource-group $rg \
    --nsg-name ERP-SERVERS-NSG \
    --name httpRule \
    --direction Inbound \
    --priority 150 \
    --source-address-prefixes "" \
    --source-port-ranges '*' \
    --source-asgs ERP-DB-SERVERS-ASG \
    --destination-address-prefixes 10.0.0.4 \
    --destination-port-ranges 80 \
    --access Deny \
    --protocol Tcp \
    --description "Deny from DataServer to AppServer on port 80 using application security group"

# to connect to your AppServer virtual machine, and check if AppServer can communicate with DataServer over HTTP.
ssh -t azureuser@$APPSERVERIP 'wget http://10.0.1.4; exit; bash'
# the response should include a 200 OK message.

# to connect to your DataServer virtual machine, and check if DataServer can communicate with AppServer over HTTP.
ssh -t azureuser@$DATASERVERIP 'wget http://10.0.0.4; exit; bash'
# you should get a Connection timed out message. Press Ctrl+C to stop the command prior to the timeout.