Omer Wazir

Getting CoreOS to work properly with Vagrant and VirtualBox

I wanted to start playing with CoreOS and decided to use Vagrant and VirtualBox. There were steps I needed to do to get the cluster working correctly. The documentation covered what I needed to do, I just jumped a step too soon and had some problems.

I read the instructions on setting up CoreOS on Vagrant. I followed the cloud config steps because I wanted to see what it was like to work with a cluster. Then I followed the steps on starting up CoreOS and I decided it was time to run vagrant up and get things going. Well I ended up with core-01 not being able to authenticate...huh.

vagrant up
...
==> core-01: Waiting for machine to boot. This may take a few minutes...
    core-01: SSH address: 127.0.0.1:2222
    core-01: SSH username: vagrant
    core-01: SSH auth method: private key
    core-01: Warning: Connection timeout. Retrying...
    core-01: Warning: Authentication failure. Retrying...

Of course I did what I always do and searched DuckDuckGo for “authentication failure retrying coreos” and found this Stack Overflow answer: CoreOS Authentication failure on vagrant up. The answer indicated that I should have read the quickstart part of the CoreOS documentation where it plainly states that if you were to use Vagrant you must do the following:

$ ssh-add ~/.vagrant.d/insecure_private_key

After doing that vagrant up worked correctly. I could ssh into any core using vagrant ssh core-<number> -- -A

Now that I can ssh into a core I tried to write to etcd following this example but I ended up with another problem.

curl -L http://127.0.0.1:4001/v1/keys/message -d value="Hello world"
Failed connect to 127.0.0.1:4001; Connection refused

Huh I missed something because this should be working. I searched issues on the CoreOS Github repo and found issue #21 where this comment illustrated to me that I should have adjusted the config.rb file before trying to test etcd. I needed to uncomment lines to allow the following code to become functional.


$new_discovery_url='https://discovery.etcd.io/new'

# To automatically replace the discovery token on 'vagrant up', uncomment
# the lines below:
#
if File.exists?('user-data') && ARGV[0].eql?('up')
 require 'open-uri'
 require 'yaml'

 token = open($new_discovery_url).read

 data = YAML.load(IO.readlines('user-data')[1..-1].join)
 data['coreos']['etcd']['discovery'] = token

 yaml = YAML.dump(data)
 File.open('user-data', 'w') { |file| file.write("#cloud-config\n\n#{yaml}") }
end
#

After fixing that I could run the following on core-01

curl -L http://127.0.0.1:4001/v1/keys/message -d value="Hello world"

and I could read the value of message across all of the cores. Pretty neat.