T6242: load-balancing reverse-proxy: Ability for ssl backends to not verify server certificates

[Embezzle]

Change Summary

Add the ability for the VyOS reverse-proxy to connect via SSL to backends without verifying the certificate of the backend server. Can be used for connecting to backend members which have self-signed certificates .

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

https://vyos.dev/T6242

Related PR(s)

Component(s) name

load-balancing -> reverse-proxy

Proposed changes

How to test

1. Create a reverse-proxy configuration using the new option:

set load-balancing reverse-proxy backend bk-01 mode 'http'
set load-balancing reverse-proxy backend bk-01 server srv-01 address '192.0.2.12'
set load-balancing reverse-proxy backend bk-01 server srv-01 port '443'
set load-balancing reverse-proxy backend bk-01 ssl no-verify
set load-balancing reverse-proxy service fe-01 backend 'bk-01'
set load-balancing reverse-proxy service fe-01 listen-address '192.0.2.11'
set load-balancing reverse-proxy service fe-01 mode 'http'
set load-balancing reverse-proxy service fe-01 port '80'

2. Check the HAProxy backend server configuration is showing the correct options:

vyos@vyos:~$ cat /var/run/haproxy/haproxy.cfg | grep "verify none"
    server srv-01 192.0.2.12:443 ssl verify none

Smoketest result

vyos@vyos:~$ /usr/libexec/vyos/tests/smoke/cli/test_load-balancing_reverse-proxy.py
test_01_lb_reverse_proxy_domain (__main__.TestLoadBalancingReverseProxy.test_01_lb_reverse_proxy_domain) ... ok
test_02_lb_reverse_proxy_cert_not_exists (__main__.TestLoadBalancingReverseProxy.test_02_lb_reverse_proxy_cert_not_exists) ...
PKI does not contain any certificates!


Certificate "cert" not found in configuration!

ok
test_03_lb_reverse_proxy_ca_not_exists (__main__.TestLoadBalancingReverseProxy.test_03_lb_reverse_proxy_ca_not_exists) ... ok
test_04_lb_reverse_proxy_backend_ssl_no_verify (__main__.TestLoadBalancingReverseProxy.test_04_lb_reverse_proxy_backend_ssl_no_verify) ... ok

----------------------------------------------------------------------
Ran 4 tests in 17.725s

OK

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[dmbaturin]

@Mergifyio backport sagitta

[mergify]

backport sagitta

✅ Backports have been created

• #3318 T6242: load-balancing reverse-proxy: Ability for ssl backends to not verify server certificates (backport #3315) has been created for branch sagitta