curl-another-host.bash

# specify the URL like usual, but point that DNS entry at a different server either by IP or by alt. domain
# https://daniel.haxx.se/blog/2018/04/05/curl-another-host/
#
curl --resolve    example.test:443:127.0.0.1    https://example.test/
curl --connect-to example.test:443:alt.test:443 https://example.test/
curl --connect-to example.test:443:alt.test:443 https://example.test/ --header "Host: alt2.test"

# and for TLS certificate checking:
openssl s_client -servername example.test -connect alt.test:443 2>/dev/null </dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' | openssl x509 -text -noout