=============================== os-client-config =============================== `os-client-config` is a library for collecting client configuration for using an OpenStack cloud in a consistent and comprehensive manner. It will find cloud config for as few as 1 cloud and as many as you want to put in a config file. It will read environment variables and config files, and it also contains some vendor specific default values so that you don't have to know extra info to use OpenStack * If you have a config file, you will get the clouds listed in it * If you have environment variables, you will get a cloud named `envvars` * If you have neither, you will get a cloud named `defaults` with base defaults Environment Variables --------------------- `os-client-config` honors all of the normal `OS_*` variables. It does not provide backwards compatibility to service-specific variables such as `NOVA_USERNAME`. If you have OpenStack environment variables set, `os-client-config` will produce a cloud config object named `envvars` containing your values from the environment. If you don't like the name `envvars`, that's ok, you can override it by setting `OS_CLOUD_NAME`. Service specific settings, like the nova service type, are set with the default service type as a prefix. For instance, to set a special service_type for trove set:: export OS_DATABASE_SERVICE_TYPE=rax:database Config Files ------------ `os-client-config` will look for a file called `clouds.yaml` in the following locations: * Current Directory * ~/.config/openstack * /etc/openstack The first file found wins. You can also set the environment variable `OS_CLIENT_CONFIG_FILE` to an absolute path of a file to look for and that location will be inserted at the front of the file search list. The keys are all of the keys you'd expect from `OS_*` - except lower case and without the OS prefix. So, region name is set with `region_name`. Service specific settings, like the nova service type, are set with the default service type as a prefix. For instance, to set a special service_type for trove (because you're using Rackspace) set: :: database_service_type: 'rax:database' Site Specific File Locations ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In addition to `~/.config/openstack` and `/etc/openstack` - some platforms have other locations they like to put things. `os-client-config` will also look in an OS specific config dir * `USER_CONFIG_DIR` * `SITE_CONFIG_DIR` `USER_CONFIG_DIR` is different on Linux, OSX and Windows. * Linux: `~/.config/openstack` * OSX: `~/Library/Application Support/openstack` * Windows: `C:\\Users\\USERNAME\\AppData\\Local\\OpenStack\\openstack` `SITE_CONFIG_DIR` is different on Linux, OSX and Windows. * Linux: `/etc/openstack` * OSX: `/Library/Application Support/openstack` * Windows: `C:\\ProgramData\\OpenStack\\openstack` An example config file is probably helpful: :: clouds: mordred: profile: hp auth: username: mordred@inaugust.com password: XXXXXXXXX project_name: mordred@inaugust.com region_name: region-b.geo-1 dns_service_type: hpext:dns compute_api_version: 1.1 monty: auth: auth_url: https://region-b.geo-1.identity.hpcloudsvc.com:35357/v2.0 username: monty.taylor@hp.com password: XXXXXXXX project_name: monty.taylor@hp.com-default-tenant region_name: region-b.geo-1 dns_service_type: hpext:dns infra: profile: rackspace auth: username: openstackci password: XXXXXXXX project_id: 610275 regions: - DFW - ORD - IAD You may note a few things. First, since `auth_url` settings are silly and embarrasingly ugly, known cloud vendor profile information is included and may be referenced by name. One of the benefits of that is that `auth_url` isn't the only thing the vendor defaults contain. For instance, since Rackspace lists `rax:database` as the service type for trove, `os-client-config` knows that so that you don't have to. In case the cloud vendor profile is not available, you can provide one called `clouds-public.yaml`, following the same location rules previously mentioned for the config files. `regions` can be a list of regions. When you call `get_all_clouds`, you'll get a cloud config object for each cloud/region combo. As seen with `dns_service_type`, any setting that makes sense to be per-service, like `service_type` or `endpoint` or `api_version` can be set by prefixing the setting with the default service type. That might strike you funny when setting `service_type` and it does me too - but that's just the world we live in. Auth Settings ------------- Keystone has auth plugins - which means it's not possible to know ahead of time which auth settings are needed. `os-client-config` sets the default plugin type to `password`, which is what things all were before plugins came about. In order to facilitate validation of values, all of the parameters that exist as a result of a chosen plugin need to go into the auth dict. For password auth, this includes `auth_url`, `username` and `password` as well as anything related to domains, projects and trusts. SSL Settings ------------ When the access to a cloud is done via a secure connection, `os-client-config` will always verify the SSL cert by default. This can be disabled by setting `verify` to `False`. In case the cert is signed by an unknown CA, a specific cacert can be provided via `cacert`. **WARNING:** `verify` will always have precedence over `cacert`, so when setting a CA cert but disabling `verify`, the cloud cert will never be validated. Client certs are also configurable. `cert` will be the client cert file location. In case the cert key is not included within the client cert file, its file location needs to be set via `key`. Cache Settings -------------- Accessing a cloud is often expensive, so it's quite common to want to do some client-side caching of those operations. To facilitate that, `os-client-config` understands passing through cache settings to dogpile.cache, with the following behaviors: * Listing no config settings means you get a null cache. * `cache.max_age` and nothing else gets you memory cache. * Otherwise, `cache.class` and `cache.arguments` are passed in `os-client-config` does not actually cache anything itself, but it collects and presents the cache information so that your various applications that are connecting to OpenStack can share a cache should you desire. :: cache: class: dogpile.cache.pylibmc max_age: 3600 arguments: url: - 127.0.0.1 clouds: mordred: profile: hp auth: username: mordred@inaugust.com password: XXXXXXXXX project_name: mordred@inaugust.com region_name: region-b.geo-1 dns_service_type: hpext:dns IPv6 ---- IPv6 may be a thing you would prefer to use not only if the cloud supports it, but also if your local machine support it. A simple boolean flag is settable either in an environment variable, `OS_PREFER_IPV6`, or in the client section of the clouds.yaml. :: client: prefer_ipv6: true clouds: mordred: profile: hp auth: username: mordred@inaugust.com password: XXXXXXXXX project_name: mordred@inaugust.com region_name: region-b.geo-1 monty: profile: rax auth: username: mordred@inaugust.com password: XXXXXXXXX project_name: mordred@inaugust.com region_name: DFW The above snippet will tell client programs to prefer returning an IPv6 address. This will result in calls to, for instance, `shade`'s `get_public_ip` to return an IPv4 address on HP, and an IPv6 address on Rackspace. Usage ----- The simplest and least useful thing you can do is: :: python -m os_client_config.config Which will print out whatever if finds for your config. If you want to use it from python, which is much more likely what you want to do, things like: Get a named cloud. :: import os_client_config cloud_config = os_client_config.OpenStackConfig().get_one_cloud( 'hp', 'region-b.geo-1') print(cloud_config.name, cloud_config.region, cloud_config.config) Or, get all of the clouds. :: import os_client_config cloud_config = os_client_config.OpenStackConfig().get_all_clouds() for cloud in cloud_config: print(cloud.name, cloud.region, cloud.config)