Weaveworks configuration management
Introduction
This project allows you to configure a machine with:
- Docker and Weave Net for development:
setup_weave-net_dev.yml - Docker and Weave Net for testing:
setup_weave-net_test.yml - Docker, Kubernetes and Weave Kube (CNI plugin):
setup_weave-kube.yml
You can then use these environments for development, testing and debugging.
Set up
You will need Python and Ansible 2.+ installed on your machine and added to your PATH in order to be able to configure environments automatically.
- On any platform, if you have Python installed:
pip install ansible - On macOS:
brew install ansible - On Linux (via Aptitude):
sudo apt install ansible - On Linux (via YUM):
sudo yum install ansible - For other platforms or more details, see here
Frequent errors during installation are:
fatal error: Python.h: No such file or directory: installpython-devfatal error: ffi.h: No such file or directory: installlibffi-devfatal error: openssl/opensslv.h: No such file or directory: installlibssl-dev
Full steps for a blank Ubuntu/Debian Linux machine:
sudo apt-get install -qq -y python-pip python-dev libffi-dev libssl-dev
sudo pip install -U cffi
sudo pip install ansible
Tags
These can be used to selectively run (--tags "tag1,tag2") or skip (--skip-tags "tag1,tag2") tasks.
output: print potentially useful output from hosts (e.g. output ofkubectl get pods --all-namespaces)
Usage
Local machine
ansible-playbook -u <username> -i "localhost", -c local setup_weave-kube.yml
Vagrant
Provision your local VM using Vagrant:
cd $(mktemp -d -t XXX)
vagrant init ubuntu/xenial64 # or, e.g. centos/7
vagrant up
then set the following environment variables by extracting the output of vagrant ssh-config:
eval $(vagrant ssh-config | sed \
-ne 's/\ *HostName /vagrant_ssh_host=/p' \
-ne 's/\ *User /vagrant_ssh_user=/p' \
-ne 's/\ *Port /vagrant_ssh_port=/p' \
-ne 's/\ *IdentityFile /vagrant_ssh_id_file=/p')
and finally run:
ansible-playbook --private-key=$vagrant_ssh_id_file -u $vagrant_ssh_user \
--ssh-extra-args="-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null" \
-i "$vagrant_ssh_host:$vagrant_ssh_port," setup_weave-kube.yml
or, for specific versions of Kubernetes and Docker:
ansible-playbook --private-key=$vagrant_ssh_id_file -u $vagrant_ssh_user \
--ssh-extra-args="-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null" \
-i "$vagrant_ssh_host:$vagrant_ssh_port," setup_weave-kube.yml \
--extra-vars "docker_version=1.12.3 kubernetes_version=1.4.4"
NOTE: Kubernetes APT repo includes only the latest version, so currently retrieving an older version will fail.
Terraform
Provision your machine using the Terraform scripts from ../provisioning, then run:
terraform output ansible_inventory > /tmp/ansible_inventory
and
ansible-playbook \
--private-key="$(terraform output private_key_path)" \
-u "$(terraform output username)" \
-i /tmp/ansible_inventory \
--ssh-extra-args="-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null" \
../../config_management/setup_weave-kube.yml
To specify versions of Kubernetes and Docker see Vagrant examples above.
N.B.: --ssh-extra-args is used to provide:
StrictHostKeyChecking=no: as VMs come and go, the same IP can be used by a different machine, so checking the host's SSH key may fail. Note that this introduces a risk of a man-in-the-middle attack.UserKnownHostsFile=/dev/null: if you previously connected a VM with the same IP but a different public key, and added it to~/.ssh/known_hosts, SSH may still fail to connect, hence we use/dev/nullinstead of~/.ssh/known_hosts.
Docker installation role
Various ways to install Docker are provided:
docker-from-docker-ce-repodocker-from-docker-repodocker-from-get.docker.comdocker-from-tarball
each producing a slightly different outcome, which can be useful for testing various setup scenarios.
The docker-install role selects one of the above ways to install Docker based on the docker_install_role variable.
The default value for this variable is configured in group_vars/all.
You can however override it with whichever role you would want to run by passing the name of the role as a key-value pair in extra-vars, e.g.:
ansible-playbook <playbook>.yml \
--extra-vars "docker_install_role=docker-from-docker-ce-repo"