# Re-core

Setting up Re-core is pretty easy, most of the work is making sure you have VM templates that it can use, check Re-pack on how to do just that.

# Setup

Its easy to get going just clone the repo and launch the REPL:


$ git clone git@github.com:re-ops/re-core.git
$ cd re-core
# tmux is required for password input
$ tmux new-session re-core
# Now start the REPL environment
$ lein repl
[re-core]λ: (go)
nil

Note: Re-core currently requires Amazon correto 8 (opens new window) JDK.

# Templates

Re-core clones templates in order to create new VM instances, we use Re-pack to create our templates which contain the minimal setup required for Re-ops to manage the instance:

re-ops user for remote access management.
authorized ssh-key (for automated access) under /home/re-ops/.ssh/authorized_keys
JRE 8 (for re-gent)

# Configuration

The Re-core section contains the configuration options for Re-core hypervisors, Elasticsearch index, logging and queue path:

{
 :re-core {

   :queue-dir "/tmp/re-core-queue/"

   :port 8082
   :https-port 8443

   :log {
     :level :info
     :path "re-core.log"
   }
   :hypervisor #profile {
     :dev {
       ; check the Hypervisors section
     }
   }
  }
}

Table 1. Re-core settings
Section	Property	Description	Comments
ports	port	Standard http port	Used for endpoint, used reverse proxy to secure
log	level	Default logging level	Optional values include: trace, debug, info, error.
log	path	Where the log file is store locally
elasticsearch	host	The host Elasticsearch is running on
	port	http API port (9200 by default)
	user	Elasticsearch user name
	pass	Elasticsearch password
	index	The index name that re-core will use
ssh	private-key-path	Private ssh key path	Used to perform remote tasks over ssh

# Hypervisors

Hypervisor configuration is located under the re-core section of re-ops.edn.

# AWS

AWS requires the following information under the re-conf/hypervisor/aws section in the configuration file:

{
  :hypervisor {
   :dev {
     :aws {
       :access-key ""
       :secret-key ""
       :ostemplates {
         :ubuntu-18.04 {:ami "" :flavor :debian}
       }
       :default-vpc {
          :vpc-id "vpc-123456" :subnet-id "subnet-123456" :assign-public true
        }
      }
    }
  }
}

Table 2. AWS configuration
Section	Property	Description	Comments
access-key		AWS access key
secret-key		AWS API secret key
ostemplates		Mappings between system os key to AMI and flavor (redhat or debian).
default-vpc	vpc-id	The id of the VPC that will be used with EC2 instances.
	subnet-id	The id of the subnet that will be used with EC2 instances.
	assign-public	Whether to assign a public IP or not.	If false then a VPN is used to access the internal VPC network.

# Digitalocean

Digitalocean (opens new window) requires the following configuration under the re-conf/hypervisor/digital-ocean section in the configuration file:

:hypervisor {
  :dev {
    :digital-ocean {
      :token ""
      :ssh-key ""
      :ostemplates {
         :ubuntu-18.04  {:image "ubuntu-18-04 :flavor :debian}
      }
     }
   }
}

Table 3. Digitalocean configuration
Section	Property	Description	Comments
token		Digitalocean authentication token
ssh-key	SSH key id in Digitalocean UI	Used for password-less access to droplets.
ostemplates		Mapping from OS key to its Digitalocean image	Check Re-pack on how to create a template

# KVM

KVM (opens new window) requires the following information under the re-conf/hypervisor/kvm section in the configuration file:

:hypervisor {
  :dev {
    :kvm  {
      :nodes {
         :remote {:username "ronen" :host "somehost" :port 22}
         ; must use localhost key for localhost
         :localhost {:username "ronen" :host "localhost" :port 22}
       }
      :ostemplates {
         :ubuntu-16.04 {:template "ubuntu-16.04" :flavor :debian}
      }
    }
  }
}

Note: we used libvirt over SSH (using key based auth).

Table 4. KVM configuration
Section	Property	Description	Comments
nodes	username	SSH user name	Add your ssh key to /home/{user}/.ssh/authorized_keys
	host	KVM node host	KVM localhost
	port	SSH port
ostemplates	template	Template VM name	check Deploy
ostemplates	flavor	OS flavor of the template	currently only :debian supported

# LXC

LXC (opens new window) require the following information under the re-conf/hypervisor/lxc section in the configuration file:

:hypervisor {
  :dev {
    :lxc {
      :auth {
        :path #join [#env HOME "/.config/lxc"]
        :p12 "certificate.p12"
        :password ""
        :crt "127.0.0.1.crt"
      }

      :nodes {
        :localhost {
           :host "127.0.0.1" :port 8443
        }
      }

      :ostemplates {
        :ubuntu-18.04.2 {:template "ubuntu-18.04.2_node-8.x" :flavor :debian}
      }
    }
  }
}

Note: check how to add a remote LXD server following this guide (opens new window).

Table 4. KVM configuration
Section	Property	Description	Comments
auth	path	LXC client certificates path	Usually defaults to ~/.config/lxc
	p12	Generated p12 client certificate	Check p12 generate
	password	p12 certificate password
	crt	The remote server crt file	Created when adding a remote LXD node
nodes	host	Remote LXD node address
nodes	port	Remote LXD host port
ostemplates	template	Container image name
ostemplates	flavor	OS flavor of the template	currently only :debian supported

Generating p12 certificate

The p12 certificate is generated from the client.crt and host.crt files:

$ openssl pkcs12 -export -out certificate.p12 -inkey client.key -in client.crt -certfile servercerts/127.0.0.1.crt

Both files are generated after a new remote is added to our local LXC client:

$ lxc remote add 127.0.0.1

← Common Re-mote →