My back-end website is a very small IOT application. Sometimes when a request is send to the back-end server it returns a 404 because the header is to big. This is caused by the cookies send to the server.
Is it possible to send only the needed cookie to the back-end server by rewriting the header on the Haproxy ?
I’m looking for something that rewrites the header for cookies from
sesion=xyz; othercookie=123
to
sesion=xyz
You can use http-request replace-header or http-request replace-value to manipulate the Cookie header for the values you need. This is available in haproxy since version 1.5.
Example from the haproxy documentation:
http-request replace-header Cookie foo=([^;]);(.) foo=\1;ip=%bi;\2
applied to:
Cookie: foo=foobar; expires=Tue, 14-Jun-2016 01:40:45 GMT;
outputs:
Cookie: foo=foobar;ip=192.168.1.20; expires=Tue, 14-Jun-2016 01:40:45 GMT;
assuming the backend IP is 192.168.1.20
haproxy http-request documentation
Related
Problem with custom header in incoming request.
The header must be called Authorization Bearer
Anyone have idea how to called Header?
Haproxy.cfg:
http-request set-var(req.token) str(""),lua.create_access_token
http-request add-header "Authorization Bearer" %[var(req.token)]
version 2.4
I have a backend that I don't control that works using magic links. If I use the magic link, I don't have to log on. I want to share the magic link externally without exposing the actual key as the key changes from time to time and I was hoping to use haproxy as a reverse proxy. I don't want the link to be open to the entire internet and would like to use basic auth as well. The problem I am facing is that the backend overwrites the Authorization header (it's required for the magic link to work) and I get stuck in a loop and need to log on every time
My workaround:
On first request I request the basic auth (works)
Then I write it to a cookie (this part works)
On each subsequent request, if the cookie exists, I read the cookie and set the Authorization header to the cookie value (this part does not work)
Then I run http_auth which in my mind should now work since I have overwritten the header
But it does not work. Any suggestions?
userlist auth-list
user myuser insecure-password mypass
frontend myfrontend
bind *:80
mode http
acl is-path path -i -m beg /publiclink
acl has_cookie req.hdr(X-MyAuth) -m found
http-request set-header Authorization %[req.hdr(X-MyAuth)] if has_cookie
http-request auth unless { http_auth(auth-list) }
http-request set-var(txn.myhostheader) req.hdr(Authorization) if { http_auth(auth-list) !has_cookie }
default_backend node
backend node
mode http
server dcnode1 192.168.0.1:8000 check
http-response set-header set-cookie "X-MyAuth=%[var(txn.myhostheader)]; Path=/" if { var(txn.myhostheader) -m found }
http-request replace-path /publiclink1(.*) /magiclink\1
http-request set-header Authorization "Key magiclink"
My answer is related to this point :
On each subsequent request, if the cookie exists, I read the cookie and set the Authorization header to the cookie value (this part does not work)
In your backend, you set the Set-Cookie: X-MyAuth=... header :
backend node
http-response set-header set-cookie "X-MyAuth=%[var(txn.myhostheader)]; Path=/" if { var(txn.myhostheader) -m found }
So the next request contains a Cookie header like this one : Cookie: .* X-MyAuth=.*.
But in your frontend, you use the X-MyAuth header (which probably does not exist) :
frontend myfrontend
acl has_cookie req.hdr(X-MyAuth) -m found
http-request set-header Authorization %[req.hdr(X-MyAuth)] if has_cookie
You may use the X-MyAuth cookie value like this :
frontend myfrontend
acl has_cookie cook(X-MyAuth) -m found
http-request set-header Authorization %[cook(X-MyAuth)] if has_cookie
A response from our web server might set a few cookies:
Set-Cookie: JSESSIONID=123;Secure
Set-Cookie: JSESSIONIDSSO=234;Secure
In HAProxy, we want to remove one of these. With 1.7, we could do:
rspidel ^Set-Cookie:\ JSESSIONIDSSO=
But we are upgrading to HAProxy 2.2, where rspidel has been removed. The replacement (http-response del-header) does not handle regex. How can I remove just the one Set-Cookie header?
Response edited because I misunderstood the question
I believe you are looking for http-response replace-header
http-response replace-header <name> <regex-match> <replace-fmt>
[ { if | unless } <condition> ]
This works like "http-request replace-header" except that it works on the
server's response instead of the client's request.
Example:
http-response replace-header Set-Cookie (C=[^;]*);(.*) \1;ip=%bi;\2
# applied to:
Set-Cookie: C=1; expires=Tue, 14-Jun-2016 01:40:45 GMT
# outputs:
Set-Cookie: C=1;ip=192.168.1.20; expires=Tue, 14-Jun-2016 01:40:45 GMT
# assuming the backend IP is 192.168.1.20.
Documentation here
You can possibly do something like this:
http-response replace-header Set-Cookie (JSESSIONIDSSO=.*) \2
Although, that would leave you with an empty Set-Cookie header.
Another option, would be to replace the value JSESSIONIDSSO with something else. i.e.
http-response replace-header Set-Cookie (JSESSIONIDSSO=[^;]*);(.*) None=None;\2
I'm upgrading from HAProxy 1.8 to 2.2 and the command reqirep has been deprecated and removed. I used this previously to automatically add Secure to cookies that weren't previously secure. I want to use the new http-response syntax.
My old code looks like this:
rspirep ^(set-cookie:\ (?:(?!(\ Secure|ASPXAUTH=)).)*)$ \1;\ Secure
This adds ; Secure to any cookie header that doesn't contain Secure or ASPXAUTH=.
I'd like to do the same thing with one of the modern http-response commands.
Here's my initial translation:
http-request replace-header Set-Cookie (.*) %[src];\ Secure if { hdr_reg(Set-Cookie) -i (?!(\ Secure|ASPXAUTH=)) }
# Replace the "Set-Cookie" header
# That contains any value
# With the initial value with "; Secure" appended to the end
# If the cookie doesn't contain " Secure" or "ASPXAUTH=", ignoring case
Is this the right approach? Have you done this successfully?
We ended up with this as a solution. It's not perfect because it will only look for Secure modifier on the end of the Set-Cookie line but it works for what we need.
http-response replace-header Set-Cookie ^((?:.(?!\ [Ss]ecure))*)$ \1;\ Secure
I'm looking for a solution with redirects to another domain if the response from HTTP server was 404.
acl not_found status 404
acl found_ceph status 200
use_backend minio_s3 rsprep ^HTTP/1.1\ 404\ (.*)$ HTTP/1.1\ 302\ Found\nLocation:\ / if not_found
use_backend ceph if found_ceph
But still not working, this rule goes to minio_s3 backend.
Thank you for you advice.
When the response from this backend has status 404, first add a Location header that will send the browser to example.com with the original URI intact, then set the status code to 302 so the browser executes a redirect.
backend my-backend
mode http
server my-server 203.0.113.113:80 check inter 60000 rise 1 fall 2
http-response set-header Location http://example.com%[capture.req.uri] if { status eq 404 }
http-response set-status 302 if { status eq 404 }
Test:
$ curl -v http://example.org/pics/funny/cat.jpg
* Hostname was NOT found in DNS cache
* Trying 127.0.0.1...
* Connected to example.org (127.0.0.1) port 80 (#0)
> GET /pics/funny/cat.jpg HTTP/1.1
> User-Agent: curl/7.35.0
> Host: example.org
> Accept: */*
The actual back-end returns 404, but we don't see it. Instead...
< HTTP/1.1 302 Moved Temporarily
< Last-Modified: Thu, 04 Aug 2016 16:59:51 GMT
< Content-Type: text/html
< Content-Length: 332
< Date: Sat, 07 Oct 2017 00:03:22 GMT
< Location: http://example.com/pics/funny/cat.jpg
The response body from the back-end's 404 error page will still be sent to the browser, but -- as it turns out -- the browser will not display it, so no harm done. This requires HAProxy 1.6 or later.
#Michael's answer is rather good, but isno't working for me for two reasons:
Mainly because the %[capture.req.uri] tag resolves to empty (HA Proxy 1.7.9 Docker image)
Also due to the fact that the original assumptions are incomplete, due to the fact that the frontend section is missing...
So I struggled for a while, as you find all kinds of answers on the Internet, between those guys who swear the 404 logic should be put in the frontend, vs those who choose the backend, and any possible kind of tags...
This is my answer, which works for me.
My use case is that if an image is not found on the backend behind HA Proxy, then an S3 bucket is checked.
The entry point is: https://myhostname:8080/path/to/image.jpeg
defaults
mode http
global
log 127.0.0.1:514 local0 debug
frontend come_on_over_here
bind :8080
# The following two lines are here to save values while we have access to them. They won't be available in the backend section.
http-request set-var(txn.path) path
http-request set-var(txn.query) query
http-request replace-value Host localhost:8080 dev.local:80
default_backend onprems_or_s3_be
backend onprems_or_s3_be
log global
acl path_photos var(txn.path) -m beg /path/prefix/i/want/to/strip/off
acl p_ext_jpeg var(txn.path) -m end .jpeg
acl is404 status eq 404
http-response set-header Location https://mybucket.s3.eu-west-3.amazonaws.com"%[var(txn.path),regsub(^/path_prefix_i_want_to_strip_off/,/)]?%[var(txn.query)]" if path_photos p_ext_jpeg is404
http-response set-status 301 if is404
server onprems_server dev.local:80 check