Unable to log in to the newly created ARM VM when using Set-AzureRmVMOSDisk with linux and attach

Question

I am trying to develop a clone workflow for my properly working ARM VM running Ubuntu. This VM was created from Bitnami LAMP image in Marketplace.

I am trying to use the -CreateOption attach option instead of fromImage, according my knowledge it should work... I am aware that there is an other option: deprovision->capture->-CreateOption fromImage, but that also have problems see Creating new ARM VM from captured image: Blob name in URL must end with '.vhd' extension error The workflow I followed is according to many description and I do not understand this login issue, hopefully I miss a simple step...

I've tried this workflow twice with different source ARM VMs and got the very same results: The new machine seems fully operational, but I can not log in with the known username password to the new machine (via SSH).

Diagnostics:

Even the web server and mysql works in the new machine properly, because after the new machine is started I can view the web sites served by it.
From the script below I've omitted the configuration of inbound rules, but I successfully allowed HTTP (see above) and SSH. The SSH connects asking the password and evaluates it as wrong.

Here is what I've done:

Stopped the fully functional ARM VM (No waagent -deprovision was ran)
Copied the OS vhd to a new .vhd blob (Success, the copy script is out of topic)
Then ran the following script with full success:

.

Login-AzureRmAccount
Select-AzureRmSubscription -SubscriptionName "Visual Studio Premium with MSDN"

# Create VM from an existing image

$location = "westeurope"
$vmSize = "Standard_DS2"

#Existing resource name parameters:
$rgName = "rg-wp"
$vnetName= "vn-wp" 
$stName = "mystorage"
#This vhd is a copy of a completely working ARM OS vhd: 
$vhdUri = "https://mystorage.blob.core.windows.net/vhds/disk-wp-01.vhd"

#Newly creatable resource names and other parameters
$vmName = "vm-wp-02"
$nicName="ni-wp-02"
$pipName="pip-wp-02"
$nsgName="nsg-wp-02"
$vhdName = "disk-wp-02"

$vnet = Get-AzureRmVirtualNetwork -Name $vnetName -ResourceGroupName $rgName
$storageAccount = Get-AzureRmStorageAccount -AccountName $stName -ResourceGroupName $rgName 

$pip = New-AzureRmPublicIpAddress -Name $pipName -ResourceGroupName $rgName -Location $location -AllocationMethod Static -DomainNameLabel $pipName 
$nsg = New-AzureRmNetworkSecurityGroup -Name $nsgName -ResourceGroupName $rgName -Location $location
$nic = New-AzureRmNetworkInterface -Name $nicName -ResourceGroupName $rgName -Location $location -SubnetId $vnet.Subnets[0].Id -PublicIpAddressId $pip.Id -NetworkSecurityGroupId $nsg.Id

# Configure VM: 
$vm = New-AzureRmVMConfig -vmName $vmName -vmSize $vmSize
$vm = Add-AzureRmVMNetworkInterface -VM $vm -Id $nic.Id
$vm = Set-AzureRmVMOSDisk -VM $vm -Name $vhdName -VhdUri $vhdUri -Linux -CreateOption attach

New-AzureRmVM -ResourceGroupName $rgName -Location $location -VM $vm

I have just tried running this against a bitnami image, and am getting an error "Creating a virtual machine from Marketplace image requires Plan information in the request" Did you experience this? — Michael B
No. However just isolated, diagnosed that case, but I think you are using the -fromImage and not the -attach. My script below runs like charm, and the VM is running like charm, "just" the login creds somehow ruined. The error message you refer I got when trinig to create a VM from a captured (not copied) image. See the described case with some added diagnostics here: stackoverflow.com/q/35871496/1157814 — g.pickardou

Michael B Michael B · Accepted Answer · 2016-03-09T11:35:19

I had a look through this, and it seems to be something within bitnami that is preventing it from logging in.

I didn't put a lot of time into trying to work out how everything connects, but there is definitely code there that checks when a new VM has been deployed from the image, as it will always regenerate the sshd keys when it does so.

All of the expected files are identical (I performed a diff between a plain ubuntu box and the bitnami box)

the error it produces is

Mar  8 20:09:19 lamp sshd[2511]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=13.69.83.238  user=ubuntu
Mar  8 20:09:21 lamp sshd[2511]: Failed password for ubuntu from 13.69.83.238 port 32991 ssh2

Yet /etc/shadow has the right salt / hash for the password I'm using. Someone with more Linux / bitnami experience might be able to pinpoint what the error is in that. But at first brush, it should be working...

This does work exactly as expected on a plain ubuntu image, so it might be simpler to build a new machine from scratch.

Otherwise you might get a better answer posting on the bitnami forums. (its very likely just a config setting)

Unable to log in to the newly created ARM VM when using Set-AzureRmVMOSDisk with linux and attach

2 Answers