Installing with limited connectivity¶
Many playbooks and roles in OpenStack-Ansible retrieve dependencies from the public Internet by default. The example configurations assume that the deployer provides a good quality Internet connection via a router on the OpenStack management network.
Deployments may encounter limited external connectivity for a number of reasons:
Unreliable or low bandwidth external connectivity
Firewall rules which block external connectivity
External connectivity required to be via HTTP or SOCKS proxies
Architectural decisions by the deployer to isolate the OpenStack networks
High security environments where no external connectivity is permitted
When running OpenStack-Ansible in network environments that block internet connectivity, we recommend the following set of practices and configuration overrides for deployers to use.
The options below are not mutually exclusive and may be combined if desired.
Example internet dependencies¶
Distribution specific packages
LXC container images
Source code repositories
GPG keys for package validation
Practice A: Mirror internet resources locally¶
You may choose to operate and maintain mirrors of OpenStack-Ansible and OpenStack dependencies. Mirrors often provide a great deal of risk mitigation by reducing dependencies on resources and systems outside of your direct control. Mirrors can also provide greater stability, performance and security.
Python package repositories¶
Many packages used to run OpenStack are installed using pip. We advise mirroring the PyPi package index used by pip. A deployer can choose to actively mirror the entire upstream PyPi repository, but this may require a significant amount of storage. Alternatively, a caching pip proxy can be used to retain local copies of only those packages which are required.
In order to configure the deployment to use an alternative index, create the file /etc/pip.conf with the following content and ensure that it resides on all hosts in the environment.
[global] index-url = http://pip.example.org/simple
In addition, it is necessary to configure easy_install to use an alternative index. easy_install is used instead of pip to install anything listed under setup_requires in setup.py during wheel builds. See https://pip.pypa.io/en/latest/reference/pip_install/#controlling-setup-requires
To configure easy_install to use an alternative index, create the file /root/.pydistutils.cfg with the following content.
[easy_install] index_url = https://pip.example.org/simple
Then, in /etc/openstack_deploy/user_variables.yml, configure the deployment to copy these files from the host into the container cache image.
# Copy these files from the host into the containers lxc_container_cache_files_from_host: - /etc/pip.conf - /root/.pydistutils.cfg
Distribution specific packages¶
Many software packages are installed on Ubuntu hosts using .deb packages. Similar packaging mechanisms exist for other Linux distributions. We advise mirroring the repositories that host these packages.
Upstream Ubuntu repositories to mirror for Ubuntu 18.04 LTS:
OpenStack-Ansible requires several other repositories to install specific components such as Galera and Ceph.
Example repositories to mirror (Ubuntu target hosts):
These lists are intentionally not exhaustive and equivalents will be required for other Linux distributions. Consult the OpenStack-Ansible playbooks and role documentation for further repositories and the variables that may be used to override the repository location.
LXC container images¶
OpenStack-Ansible relies upon community built LXC images when building
containers for OpenStack services. Deployers may choose to create, maintain,
and host their own container images. Consult the
openstack-ansible-lxc_container_create role for details on configuration
overrides for this scenario.
Source code repositories¶
OpenStack-Ansible relies upon Ansible Galaxy to download Ansible roles when
bootstrapping a deployment host. Deployers may wish to mirror the dependencies
that are downloaded by the
Deployers can configure the script to source Ansible from an alternate Git
repository by setting the environment variable
Deployers can configure the script to source Ansible role dependencies from
alternate locations by providing a custom role requirements file and specifying
the path to that file using the environment variable
Practice B: Proxy access to internet resources¶
Some networks have no routed access to the Internet, or require certain traffic to use application specific gateways such as HTTP or SOCKS proxy servers.
Target and deployment hosts can be configured to reach public internet resources via HTTP or SOCKS proxy server(s). OpenStack-Ansible may be used to configure target hosts to use the proxy server(s). OpenStack-Ansible does not provide automation for creating the proxy server(s).
Initial host deployment is outside the scope of OpenStack-Ansible and the deployer must ensure a minimum set of proxy configuration is in place, in particular for the system package manager.
Other proxy configuration¶
In addition to this basic configuration, there are other network clients on the target hosts which may be configured to connect via a proxy. For example:
Most Python network modules
These tools and their underlying libraries are used by Ansible itself and the OpenStack-Ansible playbooks, so there must be a proxy configuration in place for the playbooks to successfully access external resources.
Typically these tools read environment variables containing proxy server
settings. These environment variables can be configured in
/etc/environment if required.
It is important to note that the proxy server should only be used to access
external resources, and communication between the internal components of the
OpenStack deployment should be direct and not through the proxy. The
environment variable is used to specify hosts that should be reached directly
without going through the proxy. These often are the hosts in the management
OpenStack-Ansible provides two distinct mechanisms for configuring proxy server settings:
1. The default configuration file suggests setting a persistent proxy
configuration on all target hosts and defines a persistent
environment variable which lists all hosts/containers’ management addresses as
well as the load balancer internal/external addresses.
2. An alternative method applies proxy configuration in a transient manner
during the execution of Ansible playbooks and defines a minimum set of
management network IP addresses for
no_proxy that are required for the
playbooks to succeed. These proxy settings do not persist after an Ansible
playbook run and the completed deployment does not require them in order to be
The deployer must decide which of these approaches is more suitable for the target hosts, taking into account the following guidance:
1. Persistent proxy configuration is a standard practice and network clients on the target hosts will be able to access external resources after deployment.
2. The deployer must ensure that a persistent proxy configuration has complete
coverage of all OpenStack management network host/containers’ IP addresses in
no_proxy environment variable. It is necessary to use a list of IP
addresses, CIDR notation is not valid for
3. Transient proxy configuration guarantees that proxy environment variables
will not persist, ensuring direct communication between services on the
OpenStack management network after deployment. Target host network clients
wget will not be able to access external resources after
4. The maximum length of
no_proxy should not exceed 1024 characters due to
a fixed size buffer in the
pam_env PAM module. Longer environment variables
will be truncated during deployment operations and this will lead to
unpredictable errors during or after deployment.
Once the number of hosts/containers in a deployment reaches a certain size,
the length of
no_proxy will exceed 1024 characters at which point it is
mandatory to use the transient proxy settings which only requires a subset of
the management network IP addresses to be present in
no_proxy at deployment
Refer to global_environment_variables: and deployment_environment_variables: in the example user_variables.yml for details of configuring persistent and transient proxy environment variables.
Deployment host proxy configuration for bootstrapping Ansible¶
bootstrap-ansible.sh script used to install Ansible and
Ansible role dependencies on the deployment host to use a proxy by setting the
We recommend you set your
/etc/environment variables with proxy
settings before launching any scripts or playbooks to avoid failure.
For larger or complex environments a dedicated deployment host allows the most suitable proxy configuration to be applied to both deployment and target hosts.
Considerations when proxying TLS traffic¶
Proxying TLS traffic often interferes with the clients ability to perform
successful validation of the certificate chain. Various configuration
variables exist within the OpenStack-Ansible playbooks and roles that allow a
deployer to ignore these validation failures. Find an example
/etc/openstack_deploy/user_variables.yml configuration below:
pip_validate_certs: false galera_package_download_validate_certs: false
The list above is intentionally not exhaustive. Additional variables may exist within the project and will be named using the *_validate_certs pattern. Disable certificate chain validation on a case by case basis and only after encountering failures that are known to only be caused by the proxy server(s).