eoscprominence/imc repository overview

⁠IMC

⁠Overview

It is frequently assumed that when you're using a cloud you have access to an essentially infinite amount of resources, however this is not always the case. IMC is for situations when you have access to many small clouds (in particular opportunistic access) and you need a tool which can deploy and configure virtual infrastructure across them.

Features include:

• Selection of clouds which meet specified requirements
  • e.g. I want to deploy a CentOS 7 VM with at least 8 cores and 32 GB of RAM
• Clouds are ranked based on specified preferences
  • e.g. I would prefer my VMs to be deployed on my local private cloud, but if that is full try my national research cloud, but if that is also full then use a public cloud
• If deployment on a cloud fails, another cloud meeting requirements will be automatically tried
• Many types of failures and issues are handled automatically, including:
  • deployment failing completely
  • contextualization failure
  • infrastructure taking too long to deploy or configure
• Couds can be grouped into regions
• Can automatically deploy Ansible hosts with public IP addresses, with only one per cloud, in order to use Ansible for contextualization

IMC uses Infrastructure Manager⁠ to deploy and configure infrastructure on clouds, including OpenStack, AWS, Azure and Google Compute Platform. It can use either Ansible or Cloud-Init for contextualization. Open Policy Agent⁠ is used for making decisions about what clouds, VM flavours and images to use.

⁠Configuration

A JSON document in the following form is used to provide static information about known clouds to OPA:

{
   "clouds":{
       "cloud1":{...},
       "cloud2":{...},
       ...
       "cloudn":{...}    
   }
}

Configuration for a single cloud has the form:

{
   "name":"<name>",
   "region":"<region>",
   "quotas":{
       "cores":i,
       "instances":j
   },
   "images":{
       "<id>":{
           "name":"<name>",
           "architecture":"<arch>",
           "distribution":"<dist>",
           "type":"<type>",
           "version":"<version>"
        }   
   },
   "flavours":{
       "<id>":{
           "name":"<name>",
           "cores":i,
           "memory":j,
           "tags":{
           },
       } 
   }
}

The image name should be in a form directly useable by IM, for example gce://europe-west2-c/centos-7 (for Google) or ost://<openstack-endpoint>/<id> (for OpenStack). Meta-data is provided for each image to easily enable users to select a standard Linux distribution image at any site, e.g. CentOS 7 or Ubuntu 16.04, without needing to know in advance the image name at each site.

The examples directory has some example configs for different clouds.

Each flavour has an optional tags, which should contain key-value pairs. This can be used to specify additional information about the VM flavour, for example:

"tags":{
    "infiniband":"true"
}

Tags can be taken into account with requirements and preferences.

A inter-node network bandwidth capability can also be specified for a cloud, e.g.:

"network":{
  "bandwidth":50
}

This taken into account as a requirement or preference. For the case of a preference, region preferences have priority over network preferences. If you have multiple sites within a region, sites within that region with a network bandwidth larger than the preference will be ranked higher than others.

⁠Deployment

⁠Infrastructure Manager

Deploy Infrastructure Manager following the instructions https://github.com/grycap/im⁠. Alternatively an existing deployment can be used. For testing it is adequate to run the IM Docker container:

docker run -d --name=im -p 127.0.0.1:8899:8899 grycap/im:1.7.4

⁠Open Policy Agent

Deploy Open Policy Agent:

docker run -p 127.0.0.1:8181:8181 -v <directory>:/policies --name=opa -d openpolicyagent/opa:latest run --server /policies

where <directory> should be replaced with the path to the directory on the host containing the policy and data files (i.e. the contents of https://github.com/prominence-eosc/imc/tree/master/policies⁠).

⁠RADL files

IM uses Resource and Application Description Language (RADL) files to describe the infrastructure to be deployed. IMC must be provided with a RADL file, noting that:

• ${image} will be replaced with the disk image name (essential)
• ${instance} will be replaced with the instance type (essential)
• ${cloud} will be replaced with the name of the cloud
• ${ansible_ip} will be replaced with the public IP address of an appropriate Ansible machine (if needed)
• ${ansible_username} will be replaced with the username of an appropriate Ansible machine (if needed)
• ${ansible_private_key} will be replaced with the private key of an appropriate Ansible machine (if needed)

If the RADL needs to contain a $ character (e.g. for contexutalization) it should be escaped appropriately and written as $$.

⁠Usage