Problem to provision ssh keys on resource azurerm_linux_virtual_machine

[ghost]

This issue was originally opened by @gcontrer87 as hashicorp/terraform#24323. It was migrated here as a result of the provider split. The original body of the issue is below.

---

Terraform Version

Terraform v0.12.23

Terraform Configuration Files

resource "azurerm_linux_virtual_machine" "vm1" {
  name                = "changos"
  resource_group_name = azurerm_resource_group.rg1.name
  location            = azurerm_resource_group.rg1.location
  size                = "Standard_B1s"
  admin_username      = "gcontrer"
  network_interface_ids = [
    azurerm_network_interface.interface1.id,
    ]

  admin_ssh_key {
      username   = "gcontrer"
      public_key = file("~/azurecli2.pub")
  }

  os_disk {
    caching              = "ReadWrite"
    storage_account_type = "Standard_LRS"
  }

  source_image_reference {
    publisher = "OpenLogic"
    offer     = "CentOS"
    sku       = "7.7"
    version   = "latest"
  }
}

Debug Output

Crash Output

Expected Behavior

Public key should be aprovisioned correctly, since it follows the convention requested on the documentation:
"public_key - (Required) The Public Key which should be used for authentication, which needs to be at least 2048-bit and in ssh-rsa format. Changing this forces a new resource to be created."

Actual Behavior

When terraform plan is run, the following error appears:
terraform plan
2020/03/08 15:19:27 [WARN] Log levels other than TRACE are currently unreliable, and are supported only for backward compatibility.
Use TF_LOG=TRACE to see Terraform's internal logs.

2020/03/08 15:19:28 [ERROR] : eval: *terraform.EvalSequence, err: Error decoding "admin_ssh_key.0.public_key" for public key data

Error: Error decoding "admin_ssh_key.0.public_key" for public key data

on vm.tf line 86, in resource "azurerm_linux_virtual_machine" "vm1":
86: resource "azurerm_linux_virtual_machine" "vm1" {

Steps to Reproduce

Additional Context

It didn't work either with format ---- BEGIN SSH2 PUBLIC KEY ---- (old resource type azurerm_virtual_machine used to work with this format)

References

[rgl]

I can confirm this is not working in v2.1.0. To further add, here's my public key:

ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAAQEApPfAr86p0bQjzFJw5R/2LoxMR68CWG0YOxQQYwRQV6lCeoLyErURYFeRZsFXAnN2lHlE5QMPTeDIgQEf4zhFu8O6DCQeGEl9GUWbGizMANcSLa+sOhnLg8CNJ5BzEFEamC/JmHjHkkzQF7vFqE1XpgBwTpgJgXbYqHed3BCpNfoQHGWfzmBx25lQ0GRCm70HfBoAhwAIFukfFxqEM1Ms7gHrV7Ul9rtKt+AibAzfhXOmC/oNXftxLWCo1lOVWEAVyFMzbHcPbNF8T1nu2BcFuQnb5/ACaTpovEbkJ8iTRuHeDXn4I7snB++9fZpD4bTUQBvk/Ma7puccbjsZSzcIVQ== rgl

And its a 2048-key as you can see from ssh-keygen:

ssh-keygen -l -f ~/.ssh/id_rsa.pub
2048 SHA256:aMiPCGx6Ae2IxvPYKU9wmAlH2oaA36BKyN+nF8eeRSY rgl (RSA)

Looking at the code, there are two paths that return the same error message, which makes troubleshooting quite impossible:

• https://github.com/terraform-providers/terraform-provider-azurerm/blob/029e4e0e6490c060184054fb55c6e3838eff3664/azurerm/internal/services/compute/ssh_keys.go#L144
• https://github.com/terraform-providers/terraform-provider-azurerm/blob/029e4e0e6490c060184054fb55c6e3838eff3664/azurerm/internal/services/compute/ssh_keys.go#L150

Can those be changed to show the exact problem with the key? like, I was expecting X but got Y.

After further debugging, the problem lies in this branch (sizeDec is 164):

https://github.com/terraform-providers/terraform-provider-azurerm/blob/029e4e0e6490c060184054fb55c6e3838eff3664/azurerm/internal/services/compute/ssh_keys.go#L145-L151

I believe that branch needs to be changed to something alike:

			rsaPubKey, ok := pubKey.(ssh.CryptoPublicKey).CryptoPublicKey().(*rsa.PublicKey)
			if !ok {
				log.Fatalf("ops")
			}
			rsaPubKeyBits := rsaPubKey.Size() * 8
			log.Fatalf("RSA pub key bits is %d", rsaPubKeyBits)

which outputs 2048 with my key.

what do you think? can I submit PR with this change?

[goswami-soumik]

I am getting the same issue while creating a scale set using azurerm_linux_virtual_machine_scale_set

terraform version is 0.12.24
azurerm provider version is 2.4.0

[beaudryj]

Any updates on this ?

[stephanbuys]

Can confirm the same issue, at this point creating Azure Virtual Machines with preset ssh keys appear to be blocked unless there's a known workaround?

terraform version is 0.12.24
azurerm provider version is 2.9.0

[rgl]

@tombuildsstuff can you look into this? Should I submit a pr for this?

[nrjohnstone]

I'm getting a similar error.. Creating vms using the old azurerm_virtual_machine worked fine so I know my ssh key is 2048 bit.
Trying to use the new azurerm_linux_virtual_machine and I get an error that the key is not 2048 bit.
I'm passing my key in as a variable, but even reading it from a file gives the same error.

terraform version is 0.12.17
azurerm provider version is 2.10.0

[KevinHannisse]

I have the same. Isn't solved with the current version of Terraform/Azure

[KevinHannisse]

I used the Putty key generator, but the error is not displaying when I use ssh-keygen on Linux. That will be a work around for y'all.

[paul-haigh]

using ssh-keygen on windows also worked for me, whereas PuttyGen didn't (same PC)

[katbyte]

@rgl - happy to accept a pr making the error messages more clear!

[rgl]

@katbyte the PR is at #7061

[ghost]

This has been released in version 2.12.0 of the provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading. As an example:

provider "azurerm" {
    version = "~> 2.12.0"
}
# ... other configuration ...

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. If you feel I made an error 🤖 🙉 , please reach out to my human friends 👉 hashibot-feedback@hashicorp.com. Thanks!