id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,uname,nginx_version 1653,http2_push_preload does not recognize Link header,bjoe2k4@…,," {{{ server { listen [::]:443 http2 ssl; listen *:443 http2 ssl; ... ssl cert, server_name and root defined here ... http2_push_preload on; location = /test.html { # Works: add_header Link ""; as=style; rel=preload""; # Does not work: more_set_headers ""Link ; as=style; rel=preload""; } } }}} When a Link header is present (from PHP, Proxy or via add_header config option) and http2_push_preload is ""on"", assets get pushed correctly. However, when Link header is added by a 3rd party module (like headers-more-nginx-module or lua-nginx-module), then assets are not pushed, although the header is there when http2 header filter runs. Debug logs add_header: (more_set_headers commented out) {{{ 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 header filter 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 push resources 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 parse link: ""; as=style; rel=preload"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 push resource 2018/10/14 17:41:05 [debug] 32069#0: *31712 posix_memalign: 0000564F7A54B5F0:4096 @16 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 table size update: 0 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 push header: "":method: GET"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 push header: "":path: /css/cn.min.357a675c.css"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 push header: "":scheme: https"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 push header: "":authority: www.test.com"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 push header: ""accept-encoding: gzip, deflate, br"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 push header: ""accept-language: en-US,en;q=0.9,de;q=0.8"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 push header: ""user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2:1 create PUSH_PROMISE frame 0000564F7A60A780: sid:2 len:170 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 output header: "":status: 200"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 output header: ""date: Sun, 14 Oct 2018 15:41:05 GMT"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 output header: ""content-type: text/html; charset=utf-8"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 output header: ""vary: Accept-Encoding"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 output header: ""link: ; as=style; rel=preload"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2 output header: ""content-encoding: br"" 2018/10/14 17:41:05 [debug] 32069#0: *31712 http2:1 create HEADERS frame 0000564F7A54B888: len:117 fin:0 }}} more_set_headers: (add_header commented out) Link header is shown on line 8 {{{ 2018/10/14 17:46:55 [debug] 32487#0: *31751 http2 header filter 2018/10/14 17:46:55 [debug] 32487#0: *31751 http2 push resources 2018/10/14 17:46:55 [debug] 32487#0: *31751 http2 table size update: 0 2018/10/14 17:46:55 [debug] 32487#0: *31751 http2 output header: "":status: 200"" 2018/10/14 17:46:55 [debug] 32487#0: *31751 http2 output header: ""date: Sun, 14 Oct 2018 15:46:55 GMT"" 2018/10/14 17:46:55 [debug] 32487#0: *31751 http2 output header: ""content-type: text/html; charset=utf-8"" 2018/10/14 17:46:55 [debug] 32487#0: *31751 http2 output header: ""vary: Accept-Encoding"" 2018/10/14 17:46:55 [debug] 32487#0: *31751 http2 output header: ""link: ; as=style; rel=preload"" 2018/10/14 17:46:55 [debug] 32487#0: *31751 http2 output header: ""content-encoding: br"" 2018/10/14 17:46:55 [debug] 32487#0: *31751 posix_memalign: 0000564F7A4B14F0:4096 @16 2018/10/14 17:46:55 [debug] 32487#0: *31751 http2:1 create HEADERS frame 0000564F7A57A090: len:118 fin:0 }}} ",defect,closed,minor,,nginx-core,1.15.x,invalid,,,Linux dev-box 4.18.10-arch1-1-ARCH #1 SMP PREEMPT Wed Sep 26 09:48:22 UTC 2018 x86_64 GNU/Linux,"nginx version: nginx/1.15.3 built by gcc 8.2.1 20180831 (GCC) built with OpenSSL 1.1.1 11 Sep 2018 TLS SNI support enabled configure arguments: --prefix=/usr/local --conf-path=/etc/nginx/nginx.conf --error-log-path=/app/log/nginx.err --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-log-path=/app/log/nginx.acc --http-proxy-temp-path=/var/lib/nginx/proxy --lock-path=/run/nginx/nginx.lock --pid-path=/run/nginx/nginx.pid --with-debug --with-file-aio --with-http_gzip_static_module --with-http_stub_status_module --with-http_ssl_module --with-http_realip_module --with-http_geoip_module --with-pcre --with-pcre-jit --without-http_scgi_module --without-http_split_clients_module --without-http_ssi_module --without-http_userid_module --without-http_uwsgi_module --without-http_upstream_ip_hash_module --without-http_browser_module --without-http_memcached_module --without-http_geo_module --add-module=modules/ngx_devel_kit --add-module=modules/lua-nginx-module --add-module=modules/headers-more-nginx-module --add-module=modules/echo-nginx-module --add-module=modules/ngx_brotli --with-http_v2_module"