Using Apache Libcloud for declarative and procedural multi-cloud orchestration

New in version 2018.3.0.

Note

This walkthrough assumes basic knowledge of Salt and Salt States. To get up to speed, check out the Salt Walkthrough.

Apache Libcloud is a Python library which hides differences between different cloud provider APIs and allows you to manage different cloud resources through a unified and easy to use API. Apache Libcloud supports over 60 cloud platforms, including Amazon, Microsoft Azure, DigitalOcean, Google Cloud Platform and OpenStack.

Execution and state modules are available for Compute, DNS, Storage and Load Balancer drivers from Apache Libcloud in
SaltStack.
  • libcloud_compute - Compute -

    services such as OpenStack Nova, Amazon EC2, Microsoft Azure VMs

  • libcloud_dns - DNS as a Service -

    services such as Amazon Route 53 and Zerigo

  • libcloud_loadbalancer - Load Balancers as a Service -

    services such as Amazon Elastic Load Balancer and GoGrid LoadBalancers

  • libcloud_storage - Cloud Object Storage and CDN -

    services such as Amazon S3 and Rackspace CloudFiles, OpenStack Swift

These modules are designed as a way of having a multi-cloud deployment and abstracting simple differences between platform to design a high-availability architecture.

The Apache Libcloud functionality is available through both execution modules and Salt states.

Configuring Drivers

Drivers can be configured in the Salt Configuration/Minion settings. All libcloud modules expect a list of "profiles" to be configured with authentication details for each driver.

Each driver will have a string identifier, these can be found in the libcloud.<api>.types.Provider class for each API, http://libcloud.readthedocs.io/en/latest/supported_providers.html

Some drivers require additional parameters, which are documented in the Apache Libcloud documentation. For example, GoDaddy DNS expects "shopper_id", which is the customer ID. These additional parameters can be added to the profile settings and will be passed directly to the driver instantiation method.

libcloud_dns:
    godaddy:
        driver: godaddy
        shopper_id: 90425123
        key: AFDDJFGIjDFVNSDIFNASMC
        secret: FG(#f8vdfgjlkm)

libcloud_storage:
    google:
        driver: google_storage
        key: GOOG4ASDIDFNVIdfnIVW
        secret: R+qYE9hkfdhv89h4invhdfvird4Pq3an8rnK

You can have multiple profiles for a single driver, for example if you wanted 2 DNS profiles for Amazon Route53, naming them "route53_prod" and "route54_test" would help your administrators distinguish their purpose.

libcloud_dns:
    route53_prod:
        driver: route53
        key: AFDDJFGIjDFVNSDIFNASMC
        secret: FG(#f8vdfgjlkm)
    route53_test:
        driver: route53
        key: AFDDJFGIjdfgdfgdf
        secret: FG(#f8vdfgjlkm)

Using the execution modules

Amongst over 60 clouds that Apache Libcloud supports, you can add profiles to your Salt configuration to access and control these clouds. Each of the libcloud execution modules exposes the common API methods for controlling Compute, DNS, Load Balancers and Object Storage. To see which functions are supported across specific clouds, see the Libcloud supported methods documentation.

The module documentation explains each of the API methods and how to leverage them.

  • libcloud_compute - Compute -

    services such as OpenStack Nova, Amazon EC2, Microsoft Azure VMs

  • libcloud_dns - DNS as a Service -

    services such as Amazon Route 53 and Zerigo

  • libcloud_loadbalancer - Load Balancers as a Service -

    services such as Amazon Elastic Load Balancer and GoGrid LoadBalancers

  • libcloud_storage - Cloud Object Storage and CDN -

    services such as Amazon S3 and Rackspace CloudFiles, OpenStack Swift

For example, listing buckets in the Google Storage platform:

$ salt-call libcloud_storage.list_containers google

    local:
        |_
        ----------
        extra:
            ----------
            creation_date:
                2017-01-05T05:44:56.324Z
        name:
            anthonypjshaw

The Apache Libcloud storage module can be used to syncronize files between multiple storage clouds, such as Google Storage, S3 and OpenStack Swift

$ salt '*' libcloud_storage.download_object DeploymentTools test.sh /tmp/test.sh google_storage

Using the state modules

For each configured profile, the assets available in the API (e.g. storage objects, containers, DNS records and load balancers) can be deployed via Salt's state system.

The state module documentation explains the specific states that each module supports

  • libcloud_storage - Cloud Object Storage and CDN
    • services such as Amazon S3 and Rackspace CloudFiles, OpenStack Swift
  • libcloud_loadbalancer - Load Balancers as a Service
    • services such as Amazon Elastic Load Balancer and GoGrid LoadBalancers
  • libcloud_dns - DNS as a Service
    • services such as Amazon Route 53 and Zerigo

For DNS, the state modules can be used to provide DNS resilience for multiple nameservers, for example:

libcloud_dns:
    godaddy:
        driver: godaddy
        shopper_id: 12345
        key: 2orgk34kgk34g
        secret: fjgoidhjgoim
    amazon:
        driver: route53
        key: blah
        secret: blah

And then in a state file:

webserver:
  libcloud_dns.zone_present:
    name: mywebsite.com
    profile: godaddy
  libcloud_dns.record_present:
    name: www
    zone: mywebsite.com
    type: A
    data: 12.34.32.3
    profile: godaddy
  libcloud_dns.zone_present:
    name: mywebsite.com
    profile: amazon
  libcloud_dns.record_present:
    name: www
    zone: mywebsite.com
    type: A
    data: 12.34.32.3
    profile: amazon

This could be combined with a multi-cloud load balancer deployment,

webserver:
  libcloud_dns.zone_present:
    - name: mywebsite.com
    - profile: godaddy
    ...
  libcloud_loadbalancer.balancer_present:
    - name: web_main
    - port: 80
    - protocol: http
    - members:
        - ip: 1.2.4.5
          port: 80
        - ip: 2.4.5.6
          port: 80
    - profile: google_gce
  libcloud_loadbalancer.balancer_present:
    - name: web_main
    - port: 80
    - protocol: http
    - members:
        - ip: 1.2.4.5
          port: 80
        - ip: 2.4.5.6
          port: 80
    - profile: amazon_elb

Extended parameters can be passed to the specific cloud, for example you can specify the region with the Google Cloud API, because create_balancer can accept a ex_region argument. Adding this argument to the state will pass the additional command to the driver.

lb_test:
    libcloud_loadbalancer.balancer_absent:
        - name: example
        - port: 80
        - protocol: http
        - profile: google
        - ex_region: us-east1

Accessing custom arguments in execution modules

Some cloud providers have additional functionality that can be accessed on top of the base API, for example the Google Cloud Engine load balancer service offers the ability to provision load balancers into a specific region.

Looking at the API documentation, we can see that it expects an ex_region in the create_balancer method, so when we execute the salt command, we can add this additional parameter like this:

$ salt myminion libcloud_storage.create_balancer my_balancer 80 http profile1 ex_region=us-east1
$ salt myminion libcloud_storage.list_container_objects my_bucket profile1 ex_prefix=me

Accessing custom methods in Libcloud drivers

Some cloud APIs have additional methods that are prefixed with ex_ in Apache Libcloud, these methods are part of the non-standard API but can still be accessed from the Salt modules for libcloud_storage, libcloud_loadbalancer and libcloud_dns. The extra methods are available via the extra command, which expects the name of the method as the first argument, the profile as the second and then accepts a list of keyword arguments to pass onto the driver method, for example, accessing permissions in Google Storage objects:

$ salt myminion libcloud_storage.extra ex_get_permissions google container_name=my_container object_name=me.jpg --out=yaml

Example profiles

Google Cloud

Using Service Accounts with GCE, you can provide a path to the JSON file and the project name in the parameters.

google:
    driver: gce
    user_id: 234234-compute@developer.gserviceaccount.com
    key: /path/to/service_account_download.json
    auth_type: SA
    project: project-name