Post deployment bash script in Bicep file does not execute - bash

Question

I want to deploy an Ubuntu VM on Azure and automatically execute a few lines of Bash code right after the VM is deployed. The Bash code is supposed to install PowerShell on the VM. To do this, I use this Bicep file. Below you can see an extract of that Bicep file where I specify what Bash code I want to be executed post deployment.
resource deploymentscript 'Microsoft.Compute/virtualMachines/runCommands#2022-08-01' = {
parent: virtualMachine
name: 'postDeploymentPSInstall'
location: location
properties: {
source: {
script: '''sudo apt-get update &&\
sudo apt-get install -y wget apt-transport-https software-properties-common &&\
wget -q "https://packages.microsoft.com/config/ubuntu/$(lsb_release -rs)/packages-microsoft-prod.deb" &&\
sudo dpkg -i packages-microsoft-prod.deb &&\
sudo apt-get update &&\
sudo apt-get install -y powershell &&\
pwsh'''
}
}
}
I searched for solutions on the web but only found conflicting explanations. I made the code above with the help of this tutorial. The only difference I see is that I'm using Bash and not PowerShell like the blog post author. Thanks for your help.

Answer 1

To deploy an Ubuntu VM on Azure and automatically execute a few lines of Bash code right after the VM is deployed:
I tried to create a Linux VM and used run command to install PowerShell inside the VM while deployment and was able to achieve the desired results by running below bicep file.
#description('Name of the Network Security Group')
param networkSecurityGroupName string = 'SecGroupNet'
var publicIPAddressName = '${vmName}PublicIP'
var networkInterfaceName = '${vmName}NetInt'
var osDiskType = 'Standard_LRS'
var subnetAddressPrefix = '10.1.0.0/24'
var addressPrefix = '10.1.0.0/16'
var linuxConfiguration = {
disablePasswordAuthentication: true
ssh: {
publicKeys: [
{
path: '/home/${adminUsername}/.ssh/authorized_keys'
keyData: adminPassword
}
]
}
}
resource nic 'Microsoft.Network/networkInterfaces#2021-05-01' = {
name: networkInterfaceName
location: location
properties: {
ipConfigurations: [
{
name: 'ipconfig1'
properties: {
subnet: {
id: subnet.id
}
privateIPAllocationMethod: 'Dynamic'
publicIPAddress: {
id: publicIP.id
}
}
}
]
networkSecurityGroup: {
id: nsg.id
}
}
}
resource nsg 'Microsoft.Network/networkSecurityGroups#2021-05-01' = {
name: networkSecurityGroupName
location: location
properties: {
securityRules: [
{
name: 'SSH'
properties: {
priority: 1000
protocol: 'Tcp'
access: 'Allow'
direction: 'Inbound'
sourceAddressPrefix: '*'
sourcePortRange: '*'
destinationAddressPrefix: '*'
destinationPortRange: '22'
}
}
]
}
}
resource vnet 'Microsoft.Network/virtualNetworks#2021-05-01' = {
name: virtualNetworkName
location: location
properties: {
addressSpace: {
addressPrefixes: [
addressPrefix
]
}
}
}
resource subnet 'Microsoft.Network/virtualNetworks/subnets#2021-05-01' = {
parent: vnet
name: subnetName
properties: {
addressPrefix: subnetAddressPrefix
privateEndpointNetworkPolicies: 'Enabled'
privateLinkServiceNetworkPolicies: 'Enabled'
}
}
resource publicIP 'Microsoft.Network/publicIPAddresses#2021-05-01' = {
name: publicIPAddressName
location: location
sku: {
name: 'Basic'
}
properties: {
publicIPAllocationMethod: 'Dynamic'
publicIPAddressVersion: 'IPv4'
dnsSettings: {
domainNameLabel: dnsLabelPrefix
}
idleTimeoutInMinutes: 4
}
}
resource vm 'Microsoft.Compute/virtualMachines#2021-11-01' = {
name: vmName
location: location
properties: {
hardwareProfile: {
vmSize: vmSize
}
storageProfile: {
osDisk: {
createOption: 'FromImage'
managedDisk: {
storageAccountType: osDiskType
}
}
imageReference: {
publisher: 'Canonical'
offer: 'UbuntuServer'
sku: ubuntuOSVersion
version: 'latest'
}
}
networkProfile: {
networkInterfaces: [
{
id: nic.id
}
]
}
osProfile: {
computerName: vmName
adminUsername: adminUsername
adminPassword: adminPassword
linuxConfiguration: ((authenticationType == 'password') ? null : linuxConfiguration)
}
}
}
resource deploymentscript 'Microsoft.Compute/virtualMachines/runCommands#2022-03-01' = {
parent: vm
name: 'linuxscript'
location: location
properties: {
source: {
script: '''# Update the list of packages
sudo apt-get update;
#Install pre-requisite packages.
sudo apt-get install -y wget apt-transport-https software-properties-common;
#Download the Microsoft repository GPG keys
wget -q "https://packages.microsoft.com/config/ubuntu/$(lsb_release -rs)/packages-microsoft-prod.deb";
#Register the Microsoft repository GPG keys
sudo dpkg -i packages-microsoft-prod.deb;
#Update the list of packages after we added packages.microsoft.com
sudo apt-get update;
#Install PowerShell
sudo apt-get install -y powershell;
#Start PowerShell
pwsh'''
}
}
}
output adminUsername string = adminUsername
output hostname string = publicIP.properties.dnsSettings.fqdn
output sshCommand string = 'ssh $ {adminUsername}#${publicIP.properties.dnsSettings.fqdn}'
Deployed Successfully:
From Azure Portal:
After the deployment, When I ssh’d into my VM and ran Pwsh to check if PowerShell was installed
Installed successfully:
Refer MSDoc, run command template-MSDoc

Answer 2

Your problem is misunderstanding what the && does.
The shell will attempt to run semi-simultaneously all parts, some possibly clobbering others or not having necessary preconditions in place before starting!
Replace all instances of "&&\" with ";\" and your script should work, meaning the commands will run sequentially, waiting for the previous line to complete before attempting the subsequent lines.