Creating Virtual Machines (VM)

Mark Edmondson

2019-11-25

Launch a Virtual Machine

To launch a VM, use gce_vm(). This will:

  • Return the instance metadata if it is already running
  • Start the instance and return its metadata if its currently stopped.
  • Create a VM if you include configurations detailed below.

Reset and Stop VM

## reset instance
job <- gce_vm_reset("markdev")
  
## check job until its finished
gce_check_zone_op(job$name, wait = 20)
  
## stop VM
job <- gce_vm_stop("markdev")
  
## check job until finished
gce_check_zone_op(job$name, wait = 20)
  
inst <- gce_get_instance("markdev")
inst$status
# "TERMINATED"

External IP

You can view the external IP for an instance via gce_get_external_ip()

Creating an instance

To create an instance from scratch you need to specify:

  • Name
  • Project [if not default]
  • Zone [if not default]
  • Machine type - either a predefined type or custom CPU and memory
  • Network - usually default, specifies open ports etc.
  • Image - a source disk image containing the operating system, that may come from another image project or a snapshot

Default settings

The default settings let you create a VM like so:

The defaults for a new VM are:

  • predefined_type = "f1-micro"
  • image_project = "debian-cloud"
  • image_family = "debian-8"
  • network = "default"

Templated Container based VMs

There is support for RStudio, Shiny and OpenCPU docker images using the above to launch configurations. The configurations are located in the /inst/cloudconfig package folder.

To launch those, use the gce_vm() function and specify the argument template

You can then use gce_vm_stop, gce_vm_start etc. for your server. You are only charged for when the VM is running, so you can stop it until you need it.

Container based VMs

There is also support for launching VMs from a docker container, as configured via a cloud-init configuration file.

Here is the example from the Google documentation - save this file locally:

#cloud-config

users:
- name: cloudservice
  uid: 2000

write_files:
- path: /etc/systemd/system/cloudservice.service
  permissions: 0644
  owner: root
  content: |
    [Unit]
    Description=Start a simple docker container

    [Service]
    Environment="HOME=/home/cloudservice"
    ExecStartPre=/usr/share/google/dockercfg_update.sh
    ExecStart=/usr/bin/docker run --rm -u 2000 --name=mycloudservice gcr.io/google-containers/busybox:latest /bin/sleep 3600
    ExecStop=/usr/bin/docker stop mycloudservice
    ExecStopPost=/usr/bin/docker rm mycloudservice

runcmd:
- systemctl daemon-reload
- systemctl start cloudservice.service

If the above is saved as example.yaml you can then launch a VM using its configuration via the gce_vm_container() function:

Custom settings for VMs

You can examine different options via the various list commands:

Machine type

A list of the predefined machine types:

Images

A list of the image projects and families available is here: https://cloud.google.com/compute/docs/images

gce_list_images(image_project = "debian-cloud")

Network

Most of the time you will want to leave network to the default, at present you can only configure this in the UI.

Disks

You can also create another disk to attach to the VM via:

gce_make_disk("my-disk")

By default it will be a 500GB disk unless you specify otherwise. You can then attach this disk to the instance upon creation using the disk_source argument set to the disk resource URL.

From version 0.1.0.9000 onwards you can also specify the size of the disk when creating a VM (Thanks to @jburos)

build_vm <- gce_vm_create('my-build-image3', disk_size_gb = 20)

Metadata

You can add custom metadata by passing a named list to the instance. More details from Google documentation is here https://cloud.google.com/compute/docs/storing-retrieving-metadata

This includes useful utilities such as startup-script and shutdown-script that you can use to run shell scripts. In those cases the named list should include the script as its value.