Not able to connect to remote host via terraform OCI ,remote-exec

Question

I am new to Terraform , OCI . So I am now trying to ssh on a linux host in my OCI via cloud shell, but that host is in a private subnet. So I am trying below command but getting timeout error.

Could you please tell me where I am getting this wrong

resource "null_resource" "remote-exec" {


    provisioner "remote-exec" {
        connection {
            agent =false
            timeout = "5m"
            host ="xx.xx.xx.x"   --- This is in a private subnet(private ip address to connect to linux env)
            user = var.host_user_name
           private_key =file("${path.module}/sshkey.pem")
        }
        inline = [
            "sleep 10",
            "sudo su - oracle",
            "source EBSapps.env run",
            "cd /u01/",
            "touch ytest.txt",
        ]
    }
}

Answer 1

@Deepak .. I guess you cannot connect to instance in private subnet using private IP. You would need bastion host in this case. Before trying it from terraform, did you try it out from OCI console?. I believe you will not be able to connect to instance just by private IP. If you want complete setup in terraform, you would need to create resource for bastion-host and then you can get connect to private subnet instance via bastion host. In this case, you remote execution block will have bastion-host IP. Something similar to below

 provisioner "remote-exec" {
        connection {
            agent =false
            timeout = "5m"
            host ="xx.xx.xx.x"   --- This should be bastion host IP
            user = var.host_user_name
           private_key =file("${path.module}/sshkey.pem")
        }

References:

https://medium.com/@harjulthakkar/connect-to-private-compute-instance-using-oci-bastion-service-ca96a3ceea49

https://registry.terraform.io/providers/hashicorp/oci/latest/docs/resources/bastion_bastion