mjhjmtu

I have the following config, it's under the frontend section for tls connection and haproxy terminates https connections:

acl domain-acl-host hdr(host) -i domain.tld
rspadd X-Foo: bar if domain-acl-host
rspadd X-Baz: baz
http-response set-header X-Bar bar if domain-acl-host
use_backend backend_name if domain-acl-host

The use_backend directive works conditionally as expected (there are multiple different domain names served, and they are chosen correctly)

But headers are not added/set to the response conditionally.

I expect 3 extra headers to be added there: X-Foo, X-Baz, and X-Bar, but only X-Baz is added:

< HTTP/1.1 302 Found
< Server: nginx
< Content-Type: text/html; charset=UTF-8
< Transfer-Encoding: chunked
< Cache-Control: max-age=0, must-revalidate, private
< Date: Sun, 14 Oct 2018 20:25:59 GMT
< Location: https://domain.tld/somewhere/else
< X-Baz: baz

I'm sure I'm missing something trivial, but reading documentation or google did not help.

PS: it's haproxy 1.8.8

there is no host header in the response headers, your acl never matches.
use something like this:

 http-request set-var(txn.foo) req.hdr(host)
 http-response set-header bar 1 if var(txn.foo) foo.bar