Firewall property

IMPORTANT

Starter plans only

For Starter plans, the firewall property adds an outbound firewall to the application. This firewall has no effect on incoming requests. It defines which tcp outbound requests can leave an Adobe Commerce site. This is called egress filtering. The outbound firewall is filtering what can egress—exit or escape—your site. And when you limit what can escape, you add a powerful security tool to your server.

Default restriction policies

The firewall provides two default policies to control outbound traffic: allow and deny. The allow policy allows all outbound traffic by default. And the deny policy denies all outbound traffic by default. But when you add a rule, the default policy is overridden, and the firewall blocks all outbound traffic not allowed by the rule.

For Starter plans, we set the default policy to allow. This setting ensures that all your current outbound traffic remains unblocked until you add your egress-filtering rules. We can also set the default policy to deny upon request.

To check your default policy:

magento-cloud p:curl --project PROJECT_ID /settings | grep -i outbound

Unless you requested deny for your policy, the command should show your policy set to allow:

"outbound_restrictions_default_policy": "allow"
NOTE

Key takeaway: When you add an outbound rule, you block all outbound traffic except for the domains, IP addresses, or ports you add to the rule. So it is important to have a full outbound list defined and tested before adding it to your production site.

Firewall options

The following example shows all the firewall options that you can use to add rules for your egress filtering.

firewall:
    outbound:
        - # Common accessed domains
            domains:
                - newrelic.com
                - fastly.com
                - magento.com
                - magentocommerce.com
                - google.com
            ports:
                - 80
                - 443
            protocol: tcp # Can be omitted from rules.

        - # Adobe Stock integration
            domains:
                - account.adobe.com
                - stock.adobe.com
                - console.adobe.io
            ports:
                - 80
                - 443

        - # Payment services
            domains:
                - braintreepayments.com
                - paypal.com
            ports:
                - 80
                - 443

        - # Shipping services
            domains:
                - ups.com
                - usps.com
                - fedex.com
                - dhl.com
            ports:
                - 80
                - 443

        - # Vertex Integrated Address Cleansing
            domains:
                - mgcsconnect.vertexsmb.com
            ports:
                - 80
                - 443

        - # New Relic networks
            ips:
                - 162.247.240.0/22 # US region accounts
                - 185.221.84.0/22 # EU region accounts
            ports:
                - 443

        - # New Relic endpoints
            domains:
                - collector.newrelic.com, # US region accounts
                - collector.eu01.nr-data.net # EU region accounts
            ports:
                - 443

        - # Fastly IP ranges
            ips:
                - 23.235.32.0/20
                - 43.249.72.0/22
                - 103.244.50.0/24
                - 103.245.222.0/23
                - 103.245.224.0/24
                - 104.156.80.0/20
                - 146.75.0.0/16
                - 151.101.0.0/16
                - 157.52.64.0/18
                - 167.82.0.0/17
                - 167.82.128.0/20
                - 167.82.160.0/20
                - 167.82.224.0/20
                - 172.111.64.0/18
                - 185.31.16.0/22
                - 199.27.72.0/21
                - 199.232.0.0/16
            ports:
                - 80
                - 443

Egress filtering rules

Outbound firewall configurations are made up of rules. You can define as many rules as you need. The requirements for rules are as follows.

Each rule:

  • Must start with a hyphen (-). Adding a comment on the same line helps document and visually separate one rule from the next.
  • Must define at least one of the following options: domains, ips, or ports.
  • Must use the tcp protocol. Because this is the default protocol for all rules, you can omit it from the rule.
  • Can define domains or ips, but not both in the same rule.
  • Can include yaml comments (#) and line breaks to organize the domains, IP addresses, and ports allowed.

Each rule uses the following properties:

domains

The domains option allows a list of fully qualified domain names (FQDN).

If a rule defines domains but not ports, the firewall allows domain requests on any port.

ips

The ips option allows a list of IP addresses in the CIDR notation. You can specify single IP addresses or ranges of IP addresses.

To specify a single IP address, add the /32 CIDR prefix to the end of your IP address:

172.217.11.174/32  # google.com

To specify a range of IP addresses, use the IP Range to CIDR calculator.

If a rule defines ips but not ports, the firewall allows IP requests on any port.

ports

The ports option allows a list of ports from 1 to 65535. For most rules in the example, we added ports 80 and 443 to allow both HTTP and HTTPS requests. But for New Relic, we created rules that only allow access to domains and IP addresses on port 443, as recommended in the New Relic documentation on Network Traffic.

If a rule only defines ports, the firewall allows access to all domains and IP addresses for the ports defined.

NOTE

Port 25, the SMTP port to send email, is always blocked, without exception.

protocol

As mentioned, TCP is the default and only protocol allowed for rules. UDP and its ports are not allowed. For this reason, you can omit the protocol option from all rules. If you want to include it anyway, you must set the value to tcp, as shown in the first rule of the example.

Finding domain names to allow

To help you identify the domains to include in your egress-filtering rules, use the following command to parse your server’s dns.log file and show a list of all the DNS requests that your site has logged:

awk '($5 ~/query/)' /var/log/dns.log | awk '{print $6}' | sort | uniq -c | sort -rn

This command also shows DNS requests that were made but blocked by your egress-filtering rules. The output does not show which domains were blocked, only that requests were made. The output does not show requests made using an IP address.

Example output:

97 magento.com
93 magentocommerce.com
88 google.com
70 metadata.google.internal.0
70 metadata.google.internal
65 newrelic.com
56 fastly.com
17 mcprod-0vunku5xn24ip.ap-4.magentosite.cloud
6 advancedreporting.rjmetrics.com

Domains, in contrast to IP addresses, are typically more specific and secure for egress filtering. For example, if you add an IP address for a service that uses a CDN, you are allowing the IP address for the CDN, which can be used by hundreds or thousands of other domains. With one IP address, you could be allowing outbound access to thousands of other servers.

Testing egress-filtering rules

After collecting and configuring access rules for the domains and IP addresses your site needs, it is time to push and test.

To test your egress-filtering rules:

  1. Create a shell script of curl commands to access the domains and IP addresses in your rules. Include commands that test access to domains and IPs that should be blocked.

  2. Configure a post_deploy hook in your .magento.app.yaml file to run the script.

  3. Push your firewall configuration and your test script to your integration branch.

  4. Examine the post_deploy output from your curl commands.

  5. Refine your firewall rules, update your curl script, commit, push, and repeat.

curl script example

# curl-tests-for-egress-filtering.sh

# Use the -v option to display connection details

# Check domain access
curl -v newrelic.com
curl -v fastly.com
curl -v magento.com
curl -v magentocommerce.com
curl -v google.com
curl -v account.adobe.com
curl -v stock.adobe.com
curl -v console.adobe.io
curl -v braintreepayments.com
curl -v paypal.com
curl -v ups.com
curl -v usps.com
curl -v fedex.com
curl -v dhl.com
curl -v devdocs.magento.com

# Check domain denials
curl -v amazon.com
curl -v facebook.com
curl -v twitter.com

# IP address access
...

# IP address denials
...

post_deploy example

hooks:
    build: |
        set -e
        php ./vendor/bin/ece-tools run scenario/build/generate.xml
        php ./vendor/bin/ece-tools run scenario/build/transfer.xml
    deploy: "php ./vendor/bin/ece-tools run scenario/deploy.xml\n"
    post_deploy: |
        set -e
        php ./vendor/bin/ece-tools run scenario/post-deploy.xml
        echo "[$(date)] post-deploy hook end"
        ./curl-tests-for-egress-filtering.sh
        echo "[$(date)] curl finished"

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