Document edpm_playbook_environment for proxy configuration

Add documentation for configuring environment variables across all
data plane playbooks using the edpm_playbook_environment variable.

This change adds a new optional step in the data plane node creation
procedure that shows how to:
- Create a secret containing the edpm_playbook_environment variable
  with proxy settings
- Reference the secret using ansibleVarsFrom with secretRef in the
  OpenStackDataPlaneNodeSet CR

The documentation follows the same pattern as the existing
redhat-registry secret example and provides clear instructions
for operators who need to configure proxy settings or other
environment variables for their data plane deployments.

Docs are also added that show using edpm_bootstrap_command to set proxy
related environment variables in /etc/profile.d/proxy.sh.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>
Jira: OSPRH-15529
Depends-On: openstack-k8s-operators/edpm-ansible#1049
Signed-off-by: James Slagle <[email protected]>

Author: slagle

docs/assemblies/common_configurations.adoc

@@ -52,6 +52,27 @@ https://access.redhat.com/documentation/en-us/red_hat_satellite/6.13/html-single
 If not using Satellite version 6.13, then refer to the specific version of the
 documentation for the version of Satellite that is in use.
 
+=== Using `edpm_bootstrap_command` for configuring system proxy settings
+
+`edpm_bootstrap_command` can be used to configure system proxy settings by
+creating a file under `/etc/profile.d` that defines the proxy environment
+variables.
+
+----
+edpm_bootstrap_command: |
+    cat >/etc/profile.d/proxy.sh <<EOF
+    export http_proxy="http://USERNAME:[email protected]:3128/"
+    export https_proxy="http://USERNAME:[email protected]:3128/"
+    export no_proxy="localhost,127.0.0.1,::1" # Add any hosts to bypass the proxy
+    EOF
+----
+
+Note that these variable values won't always apply to tasks executed by
+ansible. To ensure ansible tasks always use a proxy, create the
+`edpm_playbook_environment` secret and reference it on the
+`OpenStackDataPlaneNodeSet` as shown in
+xref:proc_creating-a-set-of-data-plane-nodes.adoc.
+
 === Customizing container image locations
 
 The container images used by the various roles from edpm-ansible can pull from

docs/assemblies/proc_creating-a-set-of-data-plane-nodes.adoc

@@ -170,6 +170,17 @@ $ oc create secret generic redhat-registry \
 * Replace `<registry_username>` with the applicable user name.
 * Replace `<registry_password>` with the applicable password.
 
+. Optional: Configure environment variables for all playbooks, such as proxy settings:
++
+The `edpm_playbook_environment` variable sets environment variables that are applied to all tasks within all playbooks. This is useful for configuring proxy settings or other environment variables needed across the data plane deployment.
++
+----
+$ oc create secret generic edpm-playbook-environment \
+--from-literal edpm_playbook_environment='{"HTTP_PROXY": "http://proxy.example.com:8080", "HTTPS_PROXY": "http://proxy.example.com:8080", "NO_PROXY": "localhost,127.0.0.1", "http_proxy": "http://proxy.example.com:8080", "https_proxy": "http://proxy.example.com:8080", "no_proxy": "localhost,127.0.0.1"}'
+----
++
+* Replace the proxy values with your actual proxy server addresses.
+
 +
 ----
 apiVersion: dataplane.openstack.org/v1beta1
@@ -188,11 +199,14 @@ spec:
           name: subscription-manager
       - secretRef:
           name: redhat-registry
+      - secretRef:
+          name: edpm-playbook-environment
 ----
 
 +
 For a complete list of the Red Hat Customer Portal registration commands, see https://access.redhat.com/solutions/253273. For information about how to log into `registry.redhat.io`, see https://access.redhat.com/RegistryAuthentication#creating-registry-service-accounts-6.
 endif::[]
+
 . If your nodes are bare metal, you must configure the bare metal template, see xref:con_provisioning-bare-metal-data-plane-nodes_{context}[Provisioning bare metal data plane nodes].
 
 . Optional: The sample `OpenStackDataPlaneNodeSet` CR you copied includes default node configurations under the `nodes` section. You can add additional nodes, and edit the configured values as required. For example, to add node-specific Ansible variables that customize the node, add the following configuration to your `openstack-edpm.yaml` file: