Chapter 13. Configuring the overcloud with Ansible
Ansible is the main method to apply the overcloud configuration. This chapter provides information about how to interact with the overcloud Ansible configuration.
Although director generates the Ansible playbooks automatically, it is a good idea to familiarize yourself with Ansible syntax. For more information about using Ansible, see https://docs.ansible.com/.
Ansible also uses the concept of roles, which are different to OpenStack Platform director roles. Ansible roles form reusable components of playbooks, whereas director roles contain mappings of OpenStack services to node types.
13.1. Ansible-based overcloud configuration (config-download) Copy linkLink copied to clipboard!
The config-download feature is the method that director uses to configure the overcloud. Director uses config-download in conjunction with OpenStack Orchestration (heat) and OpenStack Workflow Service (mistral) to generate the software configuration and apply the configuration to each overcloud node. Although heat creates all deployment data from SoftwareDeployment resources to perform the overcloud installation and configuration, heat does not apply any of the configuration. Heat only provides the configuration data through the heat API. When director creates the stack, a mistral workflow queries the heat API to obtain the configuration data, generate a set of Ansible playbooks, and applies the Ansible playbooks to the overcloud.
As a result, when you run the openstack overcloud deploy command, the following process occurs:
-
Director creates a new deployment plan based on
openstack-tripleo-heat-templatesand includes any environment files and parameters to customize the plan. - Director uses heat to interpret the deployment plan and create the overcloud stack and all descendant resources. This includes provisioning nodes with the OpenStack Bare Metal service (ironic).
- Heat also creates the software configuration from the deployment plan. Director compiles the Ansible playbooks from this software configuration.
-
Director generates a temporary user (
tripleo-admin) on the overcloud nodes specifically for Ansible SSH access. - Director downloads the heat software configuration and generates a set of Ansible playbooks using heat outputs.
-
Director applies the Ansible playbooks to the overcloud nodes using
ansible-playbook.
13.2. config-download working directory Copy linkLink copied to clipboard!
Director generates a set of Ansible playbooks for the config-download process. These playbooks are stored in a working directory in the /var/lib/mistral/. This directory is named after the name of the overcloud, which is overcloud by default.
The working directory contains a set of sub-directories named after each overcloud role. These sub-directories contain all tasks relevant to the configuration of the nodes in the overcloud role. These sub-directories also contain additional sub-directories named after each specific node. These sub-directories contain node-specific variables to apply to the overcloud role tasks. As a result, the overcloud roles within the working directory use the following structure:
─ /var/lib/mistral/overcloud
|
├── Controller
│ ├── overcloud-controller-0
| ├── overcloud-controller-1
│ └── overcloud-controller-2
├── Compute
│ ├── overcloud-compute-0
| ├── overcloud-compute-1
│ └── overcloud-compute-2
...
Each working directory is a local Git repository that records changes after each deployment operation. Use the local Git repositories to track configuration changes between each deployment.
13.3. Enabling access to config-download working directories Copy linkLink copied to clipboard!
The mistral user in the OpenStack Workflow service (mistral) containers own all files in the /var/lib/mistral/ working directories. You can grant the stack user on the undercloud access to all files in this directory. This helps with performing certain operations within the directory.
Procedure
Use the
setfaclcommand to grant thestackuser on the undercloud access to the files in the/var/lib/mistraldirectory:$ sudo setfacl -R -m u:stack:rwx /var/lib/mistralThis command retains
mistraluser access to the directory.
13.4. Checking config-download log Copy linkLink copied to clipboard!
During the config-download process, Ansible creates a log file on the undercloud in the config-download working directory.
Procedure
View the log with the
lesscommand within theconfig-downloadworking directory. The following example uses theovercloudworking directory:$ less /var/lib/mistral/overcloud/ansible.log
13.5. Separating the provisioning and configuration processes Copy linkLink copied to clipboard!
The openstack overcloud deploy command runs the heat-based provisioning process and then the config-download configuration process. You can also run the command to execute each process individually.
Procedure
Source the
stackrcfile:$ source ~/stackrcRun the deployment command with the
--stack-onlyoption. Include any environment files required for your overcloud:$ openstack overcloud deploy \ --templates \ -e environment-file1.yaml \ -e environment-file2.yaml \ ... --stack-only- Wait until the provisioning process completes.
Enable SSH access from the undercloud to the overcloud for the
tripleo-adminuser. Theconfig-downloadprocess uses thetripleo-adminuser to perform the Ansible-based configuration:$ openstack overcloud admin authorizeRun the deployment command with the
--config-download-onlyoption. Include any environment files required for your overcloud:$ openstack overcloud deploy \ --templates \ -e environment-file1.yaml \ -e environment-file2.yaml \ ... --config-download-only- Wait until the configuration process completes.
13.6. Running config-download manually Copy linkLink copied to clipboard!
The working directory in /var/lib/mistral/overcloud contains the playbooks and scripts necessary to interact with ansible-playbook directly. This procedure shows how to interact with these files.
Procedure
Change to the directory of the Ansible playbook::
$ cd /var/lib/mistral/overcloud/Run the
ansible-playbook-command.shcommand to reproduce the deployment:$ ./ansible-playbook-command.shYou can pass additional Ansible arguments to this script, which are then passed unchanged to the
ansible-playbookcommand. This means that you can use other Ansible features, such as check mode (--check), limiting hosts (--limit), or overriding variables (-e). For example:$ ./ansible-playbook-command.sh --limit ControllerThe working directory contains a playbook called
deploy_steps_playbook.yaml, which runs the overcloud configuration. To view this playbook, run the following command:$ less deploy_steps_playbook.yamlThe playbook uses various task files contained in the working directory. Some task files are common to all OpenStack Platform roles and some are specific to certain OpenStack Platform roles and servers.
The working directory also contains sub-directories that correspond to each role that you define in your overcloud
roles_datafile. For example:$ ls Controller/Each OpenStack Platform role directory also contains sub-directories for individual servers of that role type. The directories use the composable role hostname format:
$ ls Controller/overcloud-controller-0The Ansible tasks are tagged. To see the full list of tags, use the CLI argument
--list-tagsforansible-playbook:$ ansible-playbook -i tripleo-ansible-inventory.yaml --list-tags deploy_steps_playbook.yamlThen apply tagged configuration using the
--tags,--skip-tags, or--start-at-taskwith theansible-playbook-command.shscript:$ ./ansible-playbook-command.sh --tags overcloudWhen
config-downloadconfigures Ceph, Ansible executesceph-ansiblefrom within theconfig-download external_deploy_steps_tasksplaybook. When you runconfig-downloadmanually, the second Ansible execution does not inherit thessh_argsargument. To pass Ansible environment variables to this execution, use a heat environment file. For example:parameter_defaults: CephAnsibleEnvironmentVariables: ANSIBLE_HOST_KEY_CHECKING: 'False' ANSIBLE_PRIVATE_KEY_FILE: '/home/stack/.ssh/id_rsa'
When you use ansible-playbook CLI arguments such as --tags, --skip-tags, or --start-at-task, do not run or apply deployment configuration out of order. These CLI arguments are a convenient way to rerun previously failed tasks or to iterate over an initial deployment. However, to guarantee a consistent deployment, you must run all tasks from deploy_steps_playbook.yaml in order.
13.7. Performing Git operations on the working directory Copy linkLink copied to clipboard!
The config-download working directory is a local Git repository. Every time a deployment operation runs, director adds a Git commit to the working directory with the relevant changes. You can perform Git operations to view configuration for the deployment at different stages and compare the configuration with different deployments.
Be aware of the limitations of the working directory. For example, if you use Git to revert to a previous version of the config-download working directory, this action affects only the configuration in the working directory. It does not affect the following configurations:
- The overcloud data schema: Applying a previous version of the working directory software configuration does not undo data migration and schema changes.
- The hardware layout of the overcloud: Reverting to previous software configuration does not undo changes related to overcloud hardware, such as scaling up or down.
-
The heat stack: Reverting to earlier revisions of the working directory has no effect on the configuration stored in the heat stack. The heat stack creates a new version of the software configuration that applies to the overcloud. To make permanent changes to the overcloud, modify the environment files applied to the overcloud stack before you rerun the
openstack overcloud deploycommand.
Complete the following steps to compare different commits of the config-download working directory.
Procedure
Change to the
config-downloadworking directory for your overcloud. In this example, the working directory is for the overcloud namedovercloud:$ cd /var/lib/mistral/overcloudRun the
git logcommand to list the commits in your working directory. You can also format the log output to show the date:$ git log --format=format:"%h%x09%cd%x09" a7e9063 Mon Oct 8 21:17:52 2018 +1000 dfb9d12 Fri Oct 5 20:23:44 2018 +1000 d0a910b Wed Oct 3 19:30:16 2018 +1000 ...By default, the most recent commit appears first.
Run the
git diffcommand against two commit hashes to see all changes between the deployments:$ git diff a7e9063 dfb9d12
13.8. Creating config-download files manually Copy linkLink copied to clipboard!
You can generate your own config-download files outside of the standard workflow. For example, you can generate the overcloud heat stack using the --stack-only option with the openstack overcloud deploy command so that you can apply the configuration separately. Complete the following steps to create your own config-download files manually.
Procedure
Generate the
config-downloadfiles:$ openstack overcloud config download \ --name overcloud \ --config-dir ~/config-download-
--nameis the name of the overcloud that you want to use for the Ansible file export. -
--config-diris the location where you want to save theconfig-downloadfiles.
-
Change to the directory that contains your
config-downloadfiles:$ cd ~/config-downloadGenerate a static inventory file:
$ tripleo-ansible-inventory \ --ansible_ssh_user heat-admin \ --static-yaml-inventory inventory.yaml
Use the config-download files and the static inventory file to perform a configuration. To execute the deployment playbook, run the ansible-playbook command:
$ ansible-playbook \
-i inventory.yaml \
--private-key ~/.ssh/id_rsa \
--become \
~/config-download/deploy_steps_playbook.yaml
To generate an overcloudrc file manually from this configuration, run the following command:
$ openstack action execution run \
--save-result \
--run-sync \
tripleo.deployment.overcloudrc \
'{"container":"overcloud"}' \
| jq -r '.["result"]["overcloudrc.v3"]' > overcloudrc.v3
13.9. config-download top level files Copy linkLink copied to clipboard!
The following file are important top level files within a config-download working directory.
Ansible configuration and execution
The following files are specific to configuring and executing Ansible within the config-download working directory.
- ansible.cfg
-
Configuration file used when running
ansible-playbook. - ansible.log
-
Log file from the last run of
ansible-playbook. - ansible-errors.json
- JSON structured file that contains any deployment errors.
- ansible-playbook-command.sh
-
Executable script to rerun the
ansible-playbookcommand from the last deployment operation. - ssh_private_key
- Private SSH key that Ansible uses to access the overcloud nodes.
- tripleo-ansible-inventory.yaml
- Ansible inventory file that contains hosts and variables for all the overcloud nodes.
- overcloud-config.tar.gz
- Archive of the working directory.
Playbooks
The following files are playbooks within the config-download working directory.
- deploy_steps_playbook.yaml
- Main deployment steps. This playbook performs the main configuration operations for your overcloud.
- pre_upgrade_rolling_steps_playbook.yaml
- Pre upgrade steps for major upgrade
- upgrade_steps_playbook.yaml
- Major upgrade steps.
- post_upgrade_steps_playbook.yaml
- Post upgrade steps for major upgrade.
- update_steps_playbook.yaml
- Minor update steps.
- fast_forward_upgrade_playbook.yaml
- Fast forward upgrade tasks. Use this playbook only when you want to upgrade from one long-life version of Red Hat OpenStack Platform to the next.
13.10. config-download tags Copy linkLink copied to clipboard!
The playbooks use tagged tasks to control the tasks that they apply to the overcloud. Use tags with the ansible-playbook CLI arguments --tags or --skip-tags to control which tasks to execute. The following list contains information about the tags that are enabled by default:
- facts
- Fact gathering operations.
- common_roles
- Ansible roles common to all nodes.
- overcloud
- All plays for overcloud deployment.
- pre_deploy_steps
-
Deployments that happen before the
deploy_stepsoperations. - host_prep_steps
- Host preparation steps.
- deploy_steps
- Deployment steps.
- post_deploy_steps
-
Steps that happen after the
deploy_stepsoperations. - external
- All external deployment tasks.
- external_deploy_steps
- External deployment tasks that run on the undercloud only.
13.11. config-download deployment steps Copy linkLink copied to clipboard!
The deploy_steps_playbook.yaml playbook configures the overcloud. This playbook applies all software configuration that is necessary to deploy a full overcloud based on the overcloud deployment plan.
This section contains a summary of the different Ansible plays used within this playbook. The play names in this section are the same names that are used within the playbook and that are displayed in the ansible-playbook output. This section also contains information about the Ansible tags that are set on each play.
- Gather facts from undercloud
Fact gathering for the undercloud node.
Tags:
facts- Gather facts from overcloud
Fact gathering for the overcloud nodes.
Tags:
facts- Load global variables
Loads all variables from
global_vars.yaml.Tags:
always- Common roles for TripleO servers
Applies common Ansible roles to all overcloud nodes, including tripleo-bootstrap for installing bootstrap packages, and tripleo-ssh-known-hosts for configuring ssh known hosts.
Tags:
common_roles- Overcloud deploy step tasks for step 0
Applies tasks from the deploy_steps_tasks template interface.
Tags:
overcloud,deploy_steps- Server deployments
Applies server-specific heat deployments for configuration such as networking and hieradata. Includes NetworkDeployment, <Role>Deployment, <Role>AllNodesDeployment, etc.
Tags:
overcloud,pre_deploy_steps- Host prep steps
Applies tasks from the host_prep_steps template interface.
Tags:
overcloud,host_prep_steps- External deployment step [1,2,3,4,5]
Applies tasks from the external_deploy_steps_tasks template interface. Ansible runs these tasks only against the undercloud node.
Tags:
external,external_deploy_steps- Overcloud deploy step tasks for [1,2,3,4,5]
Applies tasks from the deploy_steps_tasks template interface.
Tags:
overcloud,deploy_steps- Overcloud common deploy step tasks [1,2,3,4,5]
Applies the common tasks performed at each step, including puppet host configuration,
container-puppet.py, and paunch (container configuration).Tags:
overcloud,deploy_steps- Server Post Deployments
Applies server specific heat deployments for configuration performed after the 5-step deployment process.
Tags:
overcloud,post_deploy_steps- External deployment Post Deploy tasks
Applies tasks from the external_post_deploy_steps_tasks template interface. Ansible runs these tasks only against the undercloud node.
Tags:
external,external_deploy_steps
13.12. Next Steps Copy linkLink copied to clipboard!
You can now continue your regular overcloud operations.