When using the "gmake" command, the following error occurred

objs/addon/src/ngx_http_lua_kong_module.o
objs/ngx_modules.o
-L/opt/work/openresty/build/luajit-root/usr/local/openresty/luajit/lib -L/opt/work/openresty/build/luajit-root/usr/local/openresty/luajit/lib -Wl,-rpath,/usr/local/openresty/luajit/lib -Wl,-rpath,/usr/local/openresty/luajit/lib -L/tmp/build/usr/local/kong/lib -Wl,-rpath,/usr/local/kong/lib -Wl,-E -Wl,-E -ldl -lpthread -lcrypt -L/opt/work/openresty/build/luajit-root/usr/local/openresty/luajit/lib -lluajit-5.1 -lm -ldl -L/opt/work/openresty/build/luajit-root/usr/local/openresty/luajit/lib -lluajit-5.1 -lm -ldl /opt/work/pcre-8.41/.libs/libpcre.a -lssl -lcrypto -ldl -lz
-Wl,-E
objs/addon/src/ngx_http_lua_kong_module.o: In function ngx_http_lua_kong_x509_copy': /opt/work/lua-kong-nginx-module/src/ngx_http_lua_kong_module.c:397: undefined reference toX509_up_ref’
objs/addon/src/ngx_http_lua_kong_module.o: In function ngx_http_lua_kong_ffi_set_upstream_client_cert_and_key': /opt/work/lua-kong-nginx-module/src/ngx_http_lua_kong_module.c:451: undefined reference toEVP_PKEY_up_ref’
collect2: error: ld returned 1 exit status
gmake[2]: *** [objs/nginx] Error 1
gmake[2]: Leaving directory /opt/work/openresty/build/nginx-1.13.6' gmake[1]: *** [build] Error 2 gmake[1]: Leaving directory/opt/work/openresty/build/nginx-1.13.6’
gmake: *** [all] Error 2
[root@localhost openresty]#

It looks like you’re trying to build OpenResty. Which version of Kong/OpenResty are you attempting to build? Newer versions of Kong, once the OpenResty patches have been applied, require OpenSSL 1.1.x in order to build properly, so that could be what’s going wrong here.