Issuse support http/2 on haproxy and nginx
<p>I have config http/2 on haproxy(version 1.7.1) and nginx(version 1.10.1),openssl (1.0.2j), result is http/2 working nginx but when config nginx is backend server of haproxy so not working.
    This is my config on haproxy and nginx:</p>

<pre><code>###frontend#####
frontend https-in
bind *:443 ssl crt /build/ssl/ants.vn.pem alpn h2,http/1.1  
acl backend_http2 hdr_beg(host) -i ants.vn
use_backend backend_http2 if { ssl_fc_alpn -i h2 }
###backend#########
# v1.backend_http2
backend backend_http2
        mode tcp
        fullconn 100000
        balance roundrobin
        option redispatch
        option abortonclose

    option httpclose
    option forwardfor
    compression algo gzip
        compression type text/cmd text/css text/csv text/html text/javascript text/plain text/vcard text/xml application/json application/x-www-form-urlencoded application/javascript application/x-javascript
        server ants.vn 192.168.2.140:8087 check send-proxy weight 1 maxconn 8192 check ssl verify none

+backend Nginx
server {
    client_max_body_size 50m; 
    client_header_timeout  3m;
    client_body_timeout    3m;
    send_timeout           3m; 
    listen 8087 ssl http2 proxy_protocol;
    server_name ants.vn;
    ssl on;
    ssl_protocols  TLSv1.2;
    ssl_prefer_server_ciphers on;
    ssl_certificate      /build/ssl/ants.vn.crt;
    ssl_certificate_key  /build/ssl/ants.vn.key;
    access_log /data/www/logs/ants.vn_access.log;
    error_log /data/www/logs/ants.vn_error.log;
    port_in_redirect off;
    set_real_ip_from 192.168.2.0/24;
    real_ip_header   proxy_protocol;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    location /demo   {
        proxy_set_header Host            $host;
        proxy_set_header X-Real-IP       $proxy_protocol_addr;
        proxy_set_header X-Forwarded-For $proxy_protocol_addr;
        proxy_set_header  X-Forwarded-Proto   tcp;
        proxy_set_header  X-NginX-Proxy       true;
        index index.html;
        try_files $uri $uri/ /demo/index.php?$args;
        root /data/www/public_html/v1.mon.adx.vn;
    }
</code></pre>

<p>+ Result when run from backend Nginx (Ok)</p>

<ul>
<li>Result when run via Haproxy, Nginx is backend server (Fail)
GET <a href="https://ants.vn/demo/" rel="nofollow noreferrer">https://ants.vn/demo/</a> net::ERR_SPDY_PROTOCOL_ERROR</li>
</ul>