Connecting Scalr to OpenStack

Scalr needs access to your Cloud Platform(s) in order to provision and manage infrastructure on your behalf. You will therefore need to configure Scalr with your OpenStack credentials. There are 4 steps to this task.

  1. Configure OpenStack API Access
  2. Configure VPC’s
  3. Configure Instance Connection Policy
  4. Add OpenStack credentials to Scalr and link to Environments.


Your credentials are safe with us
Credentials are stored securely and encrypted. Scalr will not use your Credentials for any purpose you have not agreed to. Our terms of service can be found on the Scalr Website Policies Page.
Why Does Scalr Need Credentials?
Cloud Credentials are needed by Scalr to provision and manage cloud infrastructure on your behalf.

Configuring OpenStack for Scalr

Before creating access keys and connecting Scalr to OpenStack there are some configuration considerations that may need to implemented to ensure Scalr can connect to your instances in OpenStack.

Configure OpenStack API Access

Scalr and the Scalr Agent (“Scalarizr”) need to be able to reach the OpenStack API ports for a certain number of OpenStack services. These ports should therefore be available for access by your Scalr Server, and by the instances it is managing.


Your OpenStack installation may make those services available on a non-default port. To find out the exact port for your installation, use the following OpenStack CLI command:
keystone catalog


All ports to be opened will be TCP and only need to be open in one direction, Scalr Server > OpenStack and Scalarizr Agent > OpenStack.

Description Name Type Default Port
Nova nova compute 8774
Keystone keystone identity 5000
Neutron neutron network 9696
Swift swift object-store 8080
Glance API glance image 9292
Cinder cinder_v2 volumev2 8776

Configure Virtual Private Cloud (VPC)

You have the option to create or configure an OpenStack VPC to work with Scalr. This isn’t strictly required but please refer to Blueprint VPC NEWWIN for more information.

Configure Instance Connection Policy

You will also need to perform some additional configuration work to ensure that Scalr can connect to your OpenStack instances. There are three options for this.

  1. Public - Scalr will ONLY connect to the Public IP of instances. Only use this option if ALL instances managed by Scalr will have a Public IP.
  2. Local - Scalr will ONLY connect to the local/private IP of instances. This option is only possible if one of the following scenarios applies.
    1. All your managed instances are in the same Network or VPC as the Scalr server.
    2. You have routing or peering connections to all the other Networks/VPC’s where Scalr managed instances reside. For some information on establishing peer connections between OpenStack networks via VPN please see Neutron BGP VPN Interconnection Documentation NEWWIN for more details.
  3. Auto - (default) Scalr will connect to the Public IP of an instance if it has one, otherwise it will fall back to the local/private IP.

If you choose to use the “public” or “local” option then you need to login to your Scalr server and update the configuration in /etc/scalr-server/scalr-server.rb by adding the following entry. (NOTE: this entry must be merged with any exiting entries in the `app[:configuration] = ` structure)

app[:configuration] = {
 "scalr" => {
   "openstack" => {
     "instances_connection_policy" => "local" or "public"

After adding this entry you must re-configure scalr by running sudo scalr-server-ctl reconfigure.

Adding OpenStack Credentials to Scalr

You can now add Cloud Credentials at either the Scalr or Account Scope. You can add new credentials directly from the Main Menu or via the Environment configuration screen at the Account Scope.


Credentials added at the Scalr Scope will be available to all Accounts. Only use Scalr Scope credentials if all Accounts are trusted to use the connected cloud account.

Scalr Scope Account Scope
Environment screen
Click on the link for the cloud Click Add Credentials
  1. After selecting Add Credentials, you will be prompted to configure your Cloud Credentials and properties:
  1. Enter the credentials and other details for OpenStack and Click Save. You will see a screen similar to this.


The Openstack credentials screen includes cache clear button CACHE. Scalr maintains a cache of Openstack Flavors (instance sizes) which it refreshes every 24 hours. If you make changes to Flavors in Openstack, and these are not being reflected in Scalr, you can click on the “CLEAR” button and Scalr will refresh the cache.

You can now proceed to adding these credentials to your Environments.