CDN images on EXM email generation

Question

I have enabled CDN images on my CD servers to reduce my media load. https://doc.sitecore.com/en/developers/93/sitecore-experience-manager/enabling-cdn.html

But since EXM messages are generated on the CM server and you are not supposed to use CDN on the CM server. How can I make my EXM generate the emails with CDN media. I can't find a media path or patch just for EXM.

Answer 1

I could not find anything about EXM and CDN urls. I guess it is expected in the scaled environment, the EXM dispatcher would be on its own server witn CDN turned on.

For my CM environment, I added a new processor to the modifyImageLink pipeline that changes the server url to the CDN url via configs.

namespace Client.Project.EmailCampaign.Pipelines.GenerateLink
{
    using Sitecore.Diagnostics;
    using Sitecore.Modules.EmailCampaign.Core.Pipelines.GenerateLink;

    public class GenerateImageCdnLink : GenerateLinkProcessor
    {
        public override void Process(GenerateLinkPipelineArgs args)
        {
            Assert.IsNotNull((object)args, "Arguments can't be null");
            Assert.IsNotNull((object)args.Url, "Url can't be null");

            bool.TryParse(Sitecore.Configuration.Settings.GetSetting("ExmImageCdnEnabled"), out var exmEnabled);
            var cdnUrl = Sitecore.Configuration.Settings.GetSetting("ExmImageCdnUrl");

            if (!exmEnabled)
                return;

            if (string.IsNullOrEmpty(cdnUrl))
                return;

            args.Url = args.Url.Replace(args.ServerUrl, cdnUrl);

            args.GeneratedUrl = args.Url;
        }
    }
}

And the config

<?xml version="1.0"?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/" xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
    <sitecore>
        <pipelines>
            <modifyImageLink>
                <processor type="Client.Project.EmailCampaign.Pipelines.GenerateLink.GenerateImageCdnLink, Client.Project.EmailCampaign"
                    patch:after="processor[@type='Sitecore.Modules.EmailCampaign.Core.Pipelines.GenerateLink.ImageLink.GenerateImageLink, Sitecore.EmailCampaign']"
                    resolve="true"/>
            </modifyImageLink>
        </pipelines>        
        <settings>
            <setting name="ExmImageCdnEnabled" value="true"/>
            <setting name="ExmImageCdnUrl" value="https://mysite-test-cdn.azureedge.net"/>
        </settings>
    </sitecore>
</configuration>