I’m running HAproxy as a proxy for backend APIs on Docker Swarm. Haproxy config supports CORS, but when I try to access one of the API endpoints, it results in the following error:
"Access to XMLHttpRequest at ‘http://10.110.9.101:8080/api-customer1/v1/list’ from origin ‘http://localhost:4201’ has been blocked by CORS policy: Response to preflight request doesn’t pass access control check: It does not have HTTP ok status."
When I try to access the same API endpoint by Postman or by disabling CORS on the browser, the API is reachable and retrieves expected data.
Dockerfile:
FROM 10.110.9.100/haproxy:2.0-alpine COPY haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg
RUN ln -sf /dev/stdout /var/log/haproxy.log
haproxy.cfg
global
maxconn 2046
log 127.0.0.1 local0 debug
defaults
log global
mode http
option httpclose
option httplog
option dontlognull
retries 3
timeout connect 20s
timeout client 3m
timeout server 20m
frontend http-in
bind *:80
acl api-customer1 path_beg /api-customer1
acl api-customer2 path_beg /api-customer2
acl api-customer3 path_beg /api-customer3
acl api-docs path_beg /api-docs
mode http
option httplog
use_backend customer1-backend if api-customer1
use_backend customer2-backend if api-customer2
use_backend customer3-backend if api-customer3
use_backend docs-backend if api-docs
default_backend default-backend
timeout client 30m
Add CORS headers when Origin header is present
capture request header origin len 128
http-response add-header Access-Control-Allow-Origin '*'
http-response add-header Access-Control-Allow-Methods 'GET, HEAD, OPTIONS, POST, PUT, DELETE'
http-response add-header Access-Control-Allow-Credentials true
http-response add-header Access-Control-Allow-Headers 'Origin, Accept, X-Requested-With, Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers, APP-SESSION'
backend customer2-backend
http-request set-header Orig-Path /api-customer2/
http-request set-header X-Script-Path /api-customer2/
reqirep ^([^\ :]*)\ /api-customer2/(.*) \1\ /\2
server customer2-balancer api-customer2-v2:8080
backend customer1-backend
http-request set-header Orig-Path /api-customer1/
http-request set-header X-Script-Path /api-customer1/
reqirep ^([^\ :]*)\ /api-customer1/(.*) \1\ /\2
server customer1-balancer api-customer1-v2:8080
backend customer3-backend
http-request set-header Orig-Path /api-customer3/
http-request set-header X-Script-Path /api-customer3/
reqirep ^([^\ :]*)\ /api-customer3/(.*) \1\ /\2
server customer3-balancer api-customer3-v2:8080
backend docs-backend
http-request set-header Orig-Path /api-docs/
http-request set-header X-Script-Path /api-docs/
reqirep ^([^\ :]*)\ /api-docs/(.*) \1\ /\2
server docs-balancer api-docs:7070/docs
backend default-backend
http-request deny deny_status 400
Docker swarm services:
user@node:~$ docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
s35d89o1n078 api-customer3-v2 replicated 1/1 10.110.9.100/api-v2:latest
98h25nxy8pe0 api-docs replicated 1/1 10.110.9.100/api-docs:latest
wthb7i2s306k api-customer2-v2 replicated 1/1 10.110.9.100/api-v2:latest
46t89abwcada api-customer1-v2 replicated 1/1 10.110.9.100/api-v2:latest
kvuwekfdbnwe haproxy replicated 1/1 10.110.9.100/maxx-proxy-api:latest *:8080->80/tcp