Running Haproxy in docker container

Question

I am trying to create a Docker container from haproxy image but I run in to some problems. I followed the tutorial from Dockerhub where it says to create a Dockerfile containing

FROM haproxy:1.7  
COPY haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg

I then run docker build -t my-haproxy . And everything look good, but when i run docker run -it --rm --name haproxy-syntax-check my-haproxy haproxy -c -f /usr/local/etc/haproxy/haproxy.cfg to test the config file i get the following error`s

[ALERT] 114/152637 (1) : parsing [/usr/local/etc/haproxy/haproxy.cfg:7] : cannot find user id for 'haproxy' (0:Success)
[ALERT] 114/152637 (1) : parsing [/usr/local/etc/haproxy/haproxy.cfg:8] : cannot find group id for 'haproxy' (0:Success)
[ALERT] 114/152637 (1) : parsing [/usr/local/etc/haproxy/haproxy.cfg:32] : error opening file </etc/haproxy/errors/400.http> for custom error message <400>.
[ALERT] 114/152637 (1) : parsing [/usr/local/etc/haproxy/haproxy.cfg:33] : error opening file </etc/haproxy/errors/403.http> for custom error message <403>.
[ALERT] 114/152637 (1) : parsing [/usr/local/etc/haproxy/haproxy.cfg:34] : error opening file </etc/haproxy/errors/408.http> for custom error message <408>.
[ALERT] 114/152637 (1) : parsing [/usr/local/etc/haproxy/haproxy.cfg:35] : error opening file </etc/haproxy/errors/500.http> for custom error message <500>.
[ALERT] 114/152637 (1) : parsing [/usr/local/etc/haproxy/haproxy.cfg:36] : error opening file </etc/haproxy/errors/502.http> for custom error message <502>.
[ALERT] 114/152637 (1) : parsing [/usr/local/etc/haproxy/haproxy.cfg:37] : error opening file </etc/haproxy/errors/503.http> for custom error message <503>.
[ALERT] 114/152637 (1) : parsing [/usr/local/etc/haproxy/haproxy.cfg:38] : error opening file </etc/haproxy/errors/504.http> for custom error message <504>.
[ALERT] 114/152637 (1) : Error(s) found in configuration file : /usr/local/etc/haproxy/haproxy.cfg
[ALERT] 114/152637 (1) : Fatal errors found in configuration.

I have a group and user called haproxy. I can still create the container but it does not work. Here is my haproxy.cfg file

global
        log /dev/log    local0
        log /dev/log    local1 notice
        chroot /var/lib/haproxy
        stats socket /run/haproxy/admin.sock mode 660 level admin expose-fd listeners
        stats timeout 30s
        user haproxy
        group haproxy
        daemon

        # Default SSL material locations
        ca-base /etc/ssl/certs
        crt-base /etc/ssl/private

        # Default ciphers to use on SSL-enabled listening sockets.
        # For more information, see ciphers(1SSL). This list is from:
        #  https://hynek.me/articles/hardening-your-web-servers-ssl-ciphers/
        # An alternative list with additional directives can be obtained from
        #  https://mozilla.github.io/server-side-tls/ssl-config-generator/?server=haproxy
        ssl-default-bind-ciphers ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:RSA+AESGCM:RSA+AES:!aNULL:!MD5:!DSS
        ssl-default-bind-options no-sslv3



defaults
        log     global
        mode    http
        option  httplog
        option  dontlognull
        timeout connect 5000
        timeout client  50000
        timeout server  50000
        errorfile 400 /etc/haproxy/errors/400.http
        errorfile 403 /etc/haproxy/errors/403.http
        errorfile 408 /etc/haproxy/errors/408.http
        errorfile 500 /etc/haproxy/errors/500.http
        errorfile 502 /etc/haproxy/errors/502.http
        errorfile 503 /etc/haproxy/errors/503.http
        errorfile 504 /etc/haproxy/errors/504.http


frontend myfrontend
  bind *:80
  mode http
  default_backend mybackend

backend mybackend
  mode http
  balance roundrobin
  option httpchk HEAD / # checks against the index page
  server web1 172.17.0.2:80 check weight 10
  server web2 172.17.0.3:80 check weight 20

Answer 1

Whenever I pull the official Haproxy container, I do not see the haproxy user/group. Actually, the whole reason I have a custom image for haproxy is just to add them

RUN addgroup -g 1000 haproxy && \
    adduser -u 1000 -G haproxy -h /app -D haproxy 

Answer 2

Change the user and group to root from haproxy. It will work.

global
    log /dev/log    local0
    log /dev/log    local1 notice
    chroot /var/lib/haproxy
    stats socket /run/haproxy/admin.sock mode 660 level admin expose-fd listeners
    stats timeout 30s
    user root
    group root
    daemon