httpd-overrides

Cinder HTTPD Configuration Overrides

The cinder-operator provides mechanisms to customize the Apache HTTPD server configuration through the use of custom configuration files. This feature leverages the ExtraMounts functionality to mount custom HTTPD configuration files into the Cinder deployment.

How It Works

1. Custom Configuration Files: Create HTTPD configuration files with your custom settings
2. ConfigMap: Create ConfigMaps from files containing the overrides
3. OpenStackControlPlane Patch: Patch the control plane to mount the generated ConfigMap into Cinder containers. The HTTPD configuration automatically includes files mounted to /etc/httpd/conf_custom/*.conf

Step 1: Create Custom HTTPD Configuration

Create your custom HTTPD configuration file(s). The filename must start with httpd_custom to be automatically included by the base HTTPD configuration.

Example (httpd_custom_timeout.conf):

# Custom timeout settings for Cinder
Timeout 300
KeepAliveTimeout 15

Step 2. Create a ConfigMap

Create a Kubernetes ConfigMap containing your custom configuration files:

oc create configmap httpd-overrides --from-file=httpd_custom_timeout.conf

It is possible to add multiple configuration files containing dedicated configuration directives:

oc create configmap httpd-overrides \
  --from-file=httpd_custom_timeout.conf \
  --from-file=httpd_custom_security.conf \
  --from-file=httpd_custom_logging.conf

The following example is based on a single customization file and demonstrates how to set custom Timeout and KeepAliveTimeout parameters.

Step 3: Configure ExtraMounts in the OpenStackControlPlane

Update your OpenStackControlPlane resource to include the custom HTTPD configuration files using extraMounts. The simplest approach is to mount the entire ConfigMap to the target /etc/httpd/conf_custom mount point:

apiVersion: core.openstack.org/v1beta1
kind: OpenStackControlPlane
metadata:
  name: openstack
spec:
  cinder:
    enabled: true
    template:
      cinderAPI:
        extraMounts:
        - extraVol:
          - extraVolType: httpd-overrides
            mounts:
            - mountPath: /etc/httpd/conf_custom
              name: httpd-overrides
              readOnly: true
            volumes:
            - configMap:
                name: httpd-overrides
              name: httpd-overrides

Selective File Mount (Advanced)

If you need to mount only specific files from the ConfigMap or customize their mount paths, you can use the selective mount approach:

apiVersion: core.openstack.org/v1beta1
kind: OpenStackControlPlane
metadata:
  name: openstack
spec:
  cinder:
    enabled: true
    template:
      cinderAPI:
        extraMounts:
        - extraVol:
          - extraVolType: httpd-overrides
            mounts:
            - mountPath: /etc/httpd/conf_custom/httpd_custom_timeout.conf
              name: httpd-overrides
              readOnly: true
              subPath: httpd_custom_timeout.conf
            - mountPath: /etc/httpd/conf_custom/httpd_custom_security.conf
              name: httpd-overrides
              readOnly: true
              subPath: httpd_custom_security.conf
            - mountPath: /etc/httpd/conf_custom/httpd_custom_logging.conf
              name: httpd-overrides
              readOnly: true
              subPath: httpd_custom_logging.conf
            volumes:
            - configMap:
                name: httpd-overrides
              name: httpd-overrides

All the specified files are mounted and loaded by httpd during the Pod bootstrap process.

Common Use Cases

• Timeout Adjustments: Modify request timeout values for specific environments
• Security Headers: Add custom security headers or configurations
• Logging: Customize Apache logging configuration
• Performance Tuning: Adjust worker processes, connection limits, etc.

Verification

After deploying your custom HTTPD configuration, you can verify that the settings have been properly applied:

1. Find the Cinder Pod

First, identify the running Cinder pod:

$ oc get pods -l component=cinder-api

2. Verify Configuration Loading

Connect to the Cinder Pod and check that your custom configuration has been loaded:

# Replace <cinder-pod-name> with the actual pod name from step 1
oc rsh -c cinder-httpd <cinder-pod-name>
# Inside the pod, dump the HTTPD configuration and check for your custom settings
httpd -D DUMP_CONFIG | grep -i timeout

For the httpd_custom_timeout.conf example, you should see output similar to:

Timeout 300

3. Additional Verification Commands

You can also verify other aspects of the configuration:

# Check all loaded configuration files
$ httpd -D DUMP_INCLUDES
Included configuration files:
  (*) /etc/httpd/conf/httpd.conf
    (14) /etc/httpd/conf.modules.d/00-base.conf
    (14) /etc/httpd/conf.modules.d/00-brotli.conf
    (14) /etc/httpd/conf.modules.d/00-dav.conf
    (14) /etc/httpd/conf.modules.d/00-mpm.conf
    (14) /etc/httpd/conf.modules.d/00-optional.conf
    (14) /etc/httpd/conf.modules.d/00-proxy.conf
    (14) /etc/httpd/conf.modules.d/00-ssl.conf
    (14) /etc/httpd/conf.modules.d/00-systemd.conf
    (14) /etc/httpd/conf.modules.d/01-cgi.conf
    (14) /etc/httpd/conf.modules.d/10-wsgi-python3.conf
    (25) /etc/httpd/conf.d/10-cinder_wsgi.conf
      (40) /etc/httpd/conf_custom/httpd_custom_timeout.conf

Deploy the Sample

The cinder-operator repository includes a sample that can be used to deploy cinder with httpd overrides (it set a particular Timeout to 300s). This sample is provided as a working reference example and is not necessarily meant to serve as a deployment recommendation for production environments.

If you're using install_yamls and already have CRC (Code Ready Containers) running, you can deploy the httpd overrides example with the following steps:

# Navigate to the install_yamls directory
$ cd install_yamls
# Set up the CRC storage and deploy OpenStack Catalog
$ make crc_storage openstack
# Init operators
$ make openstack
# Deploy OpenStack operators
$ make openstack_init
# Generate the OpenStack deployment file
$ oc kustomize . > ~/openstack-deployment.yaml
# Set the path to the deployment file
$ export OPENSTACK_CR=`realpath ~/openstack-deployment.yaml`

This will create the necessary ConfigMap and a deployable OpenStackControlPlane yaml with the custom timeout configuration applied.