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Last pushed: 6 months ago
Short Description
Cluster node registration tool
Full Description





A tool that helps bootstrapping nodes based on dynamic variables.

The usecase that gave birth to this tool:

Kubernetes cluster in AWS,
all nodes run CoreOS Container Linux,
2 AMI, one for master and one for workers,
2 autoscalling groups, one master and one workers

NodeReg runs as a systemd one shot before any kubernetes components, this way
we ensures it has the right certificates and any other dependencies

Supported Cloud Providers

Currently only AWS is supported

How to run

  • :code:nodereg -c /path/to/custom/config

There is also a docker image available:

  • :code:docker run -v my.config:/my.config viruxel/nodereg -c /my.config

For developing:

  • :code:docker build -f -t nodereg-dev . && docker run -it --entrypoint tox nodereg-dev


Detect if instance is running to build the AMI, if so loops forever.

Builds a hostname based on node tags and ip address.
Updates the host with the new hostname.

Hosted Zone
Builds a FQDN based on hostname and hosted zone name.
Updates the hosted zone with A record.

AWS Instance IAM Role policy needed:

.. code:: json

"Version": "2012-10-17",
"Statement": [
"Action": [
"Effect": "Allow",
"Resource": [
"arn:aws:route53:::hostedzone/{{ hosted_zone }}"
Downloads a CA and makes it available system wide.
Generates a certificate for node FQDN and IP Address.
Allow downloading other certificates.
NOTE: This module downloads private keys as well.

It generates a Systemd drop-in file that sets environment variables used by Etcd to
either join or create a new cluster.
Remove stale members.
This works well with how Etcd is run in CoreOS

AWS Instance IAM Role policy needed:

.. code:: json

"Version": "2012-10-17",
"Statement": [
"Effect": "Allow",
"Action": "autoscaling:DescribeAutoScalingGroups",
"Resource": ""
"Effect": "Allow",
"Action": "autoscaling:DescribeAutoScalingInstances",
"Resource": "
"Version": "2012-10-17",
"Statement": [
"Effect": "Allow",
"Action": "ec2:Describe",
"Resource": "

Default Config

.. code:: yaml


# The tag used to detect if node is running build an AMI from it.
ami_build_tag: is_ami_build
# Chroot to this path. Usefull if nodereg runs
# in a container and you want to change the host.
# Set it to false if no chroot required
chroot_path: /media/root
# list of modules to run
  - hostname
  - hosted_zone
  - tinycert
  - etcd


# The glue between hostname components
glue: ''
# Consider node tag value
tag_name: Role
# Consider IP address
  # The last N octets of the IP address
  octets: 2
  # The glue between octets
  glue: '-'


# The name of the hosted zone

Get certificates from

email: test
passphrase: test
api_token: test

# Make sure the CA cert is present and recognized system-wide
# tinycert CA id
# NOTE: the common name of the certificate is used as filename
ca_id: 100
ca_path: /media/root/etc/ssl/certs
certificates_path: /media/root/etc/ssl/node_certs
# Make sure the node has a certificate/key for it's FQDN and IP Address
node_certificate: yes
# Download other certificate/keys by tinycert id
# NOTE: the common name of the certificate is used as filename
certificates: []

client_schema: http
client_port: 2379
peer_schema: http
peer_port: 2380
drop_in_file: /media/root/etc/systemd/system/etcd.service.d/70-initial-cluster.conf

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