Akamai Connector for Varnish

The Akamai Connector for Varnish allows for the integration of data and configuration between an origin Varnish Cache server and Akamai's CDN network.

Installation

Installing the Connector involves:

  • Installing the Akamai VMOD into the Varnish Cache installation.
  • Copying the Akamai VCLs into the VCL root directory.
  • Configuration of Akamai CCU API parameters for purge coordination (optional)

There are two ways to install the Connector:

  • Via package for Varnish Plus
  • Via source for Varnish Cache open-source

Both setups require the post installation steps of copying the Akamai VCLs and configuration into their final locations.

Varnish Plus Installation

In order to install the Akamai Connector for Varnish Plus, you first need to setup access to our Varnish Plus repo. If you have not already done so, please contact LA support at akamai-connector@varnish-software.com to get assistance with repo setup.

Ubuntu Installation

To install:

    
    $ apt-get install varnish-plus-akamai-connector
    

Redhat Enterprise Linux Installation

To install:

    
    $ yum install varnish-plus-akamai-connector
    

Varnish Cache Open Source Installation

In order to install the Akamai Connector for Varnish Cache open source, you need access to the source tarball (akamai-connector-VERSION.tar.gz). If you have not done so already, please email akamai-connector@varnish-software.com to request LA access to the Akamai Connector for Varnish Cache open source.

Before starting, make sure you have the following developer packages and libraries installed.

For Red Hat distributions:

    
    $ yum install varnish-plus-devel curl-devel openssl-devel python-docutils
    

For Debian and Ubuntu distributions:

    
    $ apt-get install varnish-plus-dev libcurl4-openssl-dev python-docutils make
    

First, download the Akamai Connector source tarball to your server, extract the source, and cd into the directory:

    
    $ wget [URL]
    $ tar -xvzf akamai-connector-VERSION.tar.gz
    $ cd akamai-connector-VERSION
    

The above [URL] will be provided to you by Varnish Software.

If you have installed Varnish Cache open source from package or have Varnish Cache installed using a standard installation prefix, run:

    
    $ ./configure
    

If you have installed Varnish Cache using an alternate installation prefix, you need to specify the location of the pkgconfig folder (the one containing varnishapi.pc) and export it as PKG_CONFIG_PATH before running configure.

Next, compile the VMOD:

    
    $ make
    

You can now optionally test the VMOD and VCL against your Varnish Cache installation:

    
    $ make check
    

Finally, install the Akamai Connector VMOD and VCL:

    
    $ make install
    

Post Installation Setup

After installation (both Varnish Plus and open source), you need to copy the VCL and Akamai CCU API configuration into their expected locations.

You can do this via the provided installation script:

    
    $ akamai-connector-setup.sh install
    

Running the script without the install argument will give you the locations of the Akamai VCLs and configuration file if you would like to manually install. If you have a previous configuration in place, use the force-* install targets to force install the configuration.

Configuration

The following configuration steps are required to get the Akamai Connector running within your Varnish Cache setup.

Automatic VCL Integration

To auto configure the Akamai Connector into your Varnish Cache VCL configuration, add the following 3 lines to the top of your VCL:

    
    import std;
    import akamai;
    include "akamai_auto.vcl";
    

This will automatically hook Akamai request and response logic into the appropriate vcl_* subroutines. All Connector functionality is enabled and no further configuration is required.

Note that if you already have import std; in your VCL, you do not need to import it again.

Purge Synchronization

If you would like to synchronize purge requests on this host to the Akamai network, the following Akamai CCU API fields need to be configured within the akamai-connector.conf file:

  • purge_host
  • purge_client_token
  • purge_client_secret
  • purge_access_token

Omitting these fields or removing this configuration file will cause the Akamai purge functionality to be skipped entirely.

You can also point Varnish Cache to an alternate configuration path by setting VMOD_AKAMAI_CONFIG_FILE to the alternate path. For example:

    
    export VMOD_AKAMAI_CONFIG_FILE=/opt/akamai/.ac.conf
    

Advanced VCL Integration

To selectively choose which features of the Connector you wish to use, you can use the following vcl subroutines (via akamai.vcl):

  • akamai_init_sureroute
  • akamai_recv_timeout
  • akamai_recv_esi
  • akamai_recv_device_detection
  • akamai_recv_true_client_ip
  • akamai_recv_sureroute
  • akamai_purge
  • akamai_deliver_edge_control
  • akamai_deliver_esi
  • akamai_deliver_vary
  • akamai_deliver_via

Each subroutines need to be called in the appropriate vcl_* subroutine as specified in the 2nd part of the name. For example, akamai_deliver_edge_control needs to be called in vcl_deliver. If multiple subroutines have the same functionality label, as specified by the 3rd part of the name, each one needs to be invoked. For example, both akamai_recv_esi and akamai_deliver_esi need to be called to integrate ESI with Akamai.

Sureroute Example:

    
    import std;
    import akamai;
    include "akamai.vcl";

    sub vcl_init {
        call akamai_init_sureroute;
    }

    sub vcl_recv {
        call akamai_recv_sureroute;
    }
    

If you have unused subroutines, you can disable Varnish Cache from reporting this as an error by adding the following startup parameter to varnishd:

    
    -p vcc_err_unref=false
    

Feature Overview

The Akamai Connector for Varnish offers the following functionality.

Object TTL and Grace

The Varnish Cache internal value of beresp.ttl, beresp.grace, and beresp.uncacheable will be synchronized with the Akamai CDN on each request. These values will supersede the Cache-Control header.

In your Luna Property Configuration for Akamai, set your caching behavior to honor origin cache control and expires.

Purge Synchronization

When a purge request is handled by Varnish Cache, the Connector will synchronize the invalidation request against the Akamai CDN. The Connector will use the value of req.url and req.http.Host for invalidation.

The akamai-connector.conf needs to have all of the purge_* fields filled in, otherwise purge synchronization is skipped on this host.

If purge synchronization is configured, Varnish Cache will relay the Akamai CCU API response as its purge response.

CCU API credentials need to be generated via the Luna Control Center.

True Client IP

The Varnish Cache value of req.http.True-Client-IP will always contain the True Client IP of the requestor.

In Luna, make sure the header used is True-Client-IP.

SureRoute

The Connector will respond to requests for /akamai/testobject.html with a native SureRoute response.

The response size is configured via sureroute_resp_bytes in akamai-connector.conf.

In Luna, make sure the SureRoute test object path is /akamai/testobject.html.

ESI

ESI processing in Varnish Cache is deferred to Akamai when requests originate from the Akamai CDN.

In Luna, make sure the ESI processor is enabled.

Device Characterization

Each characteristic in the X-Akamai-Device-Characteristics field will be put into its own header. The header name is X-ADC-[characteristic] where [characteristic] is the characteristic name. For example, the value of is_mobile will be put into the X-ADC-is_mobile header.

Connection Keep-Alive

Connections between Akamai CDN and Varnish Cache will be held open for 301 seconds.

This is only supported in Varnish Plus.

Getting Help

For LA support, please contact: akamai-connector@varnish-software.com