Custom domain implementation for Intercom's Educate Help Center using a reverse proxy. Select appropriate configuration for your setup. Normal instructions on setting up custom domain will SSL detailed here https://developers.intercom.com/docs/set-up-your-custom-domain

apache.conf

# Step 1: set up normal server with HTTPS https://letsencrypt.org/
# Step 2: set up proxy settings as shown below
# Step 3: set custom domain in Intercom Help Center settings

<IfModule mod_ssl.c>
<VirtualHost *:443>
        ServerName your-help-site.custom-domain.com # specify your custom domain here

        SSLEngine on
        SSLProxyVerify none
        SSLProxyEngine on

        SSLProxyCheckPeerCN off
        SSLProxyCheckPeerName off
        SSLProxyCheckPeerExpire off

        SSLCertificateFile /path/to/your/fullchain.pem
        SSLCertificateKeyFile /path/to/your/privkey.pem

        ProxyPreserveHost On
        ProxyPass / https://custom.intercom.help/
        ProxyPassReverse / https://custom.intercom.help/
</VirtualHost>
</IfModule>

nginx.conf

# Step 1: set up normal server with HTTPS https://letsencrypt.org/
# Step 2: set up proxy settings as shown below
# Step 3: set custom domain in Intercom Help Center settings

location / {
    # using "set" is important as IP addresses of Intercom servers 
    # changes dynamically. "set" enables nginx to follow dynamic IPs
    set $intercom "https://custom.intercom.help:443"; 
    proxy_set_header Host $host;
    proxy_pass $intercom;
}


# SSL setup - sample based on letsencrypt
listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/your-help-site.custom-domain.com-0001/fullchain.pem;   # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/your-help-site.custom-domain.com-0001/privkey.pem; # managed by Certbot
include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot

# force https 
if ($scheme != "https") {
        return 301 https://$host$request_uri;
} # managed by Certbot

nginx details was shared by Martin from Koalect.com 😄

If you need to handle URL redirections from an old help site, check out this related gist https://gist.github.com/thewheat/a45941cbeab21931e00b7d5c16d4b63b

Cloudfront/Route 53 configuration example

You first need to create a new distribution in Cloudfront as "Web" and add the following details:

Origin Settings
Origin Domain Name: custom.intercom.help
Origin Protocol Policy: HTTP Only

Default Cache Behavior Settings
Viewer Protocol Policy: Redirect HTTP to HTTPS
Allowed HTTP Methods: GET, HEAD, OPTIONS
Forward Headers: All
Query String Forwarding and Caching: Forward all, cache based on all
​
Distribution Settings
Alternate Domain Names (CNAMEs): [Custom domain used in your Educate settings]
SSL Certificate: Your custom SSL Certificate
Custom SSL Client Support: Only Clients that Support Server Name Indication (SNI)
​```
​
After this distribution is created, you can simply add it to Route53. These are the settings you can use:

​```
Name: [Custom domain used in your Help Center settings]
Alias: Yes
Alias Target: [CloudFront Distribution you just created]
​```