All Zabbix binaries have a default configuration file, except for zabbix_web_service.
For consistency it would be good to also include it, looks like only a small change in make file is required.
Agent2 config entry for comparison:
grep -RIn AGENT2_CONFIG_FILE configure.ac:2025:AGENT2_CONFIG_FILE="${sysconfdir}/zabbix_agent2.conf" configure.ac:2104:AC_SUBST(AGENT2_CONFIG_FILE) configure.ac:2347:AGENT2_CONFIG_FILE=`eval echo "${AGENT2_CONFIG_FILE}"` configure.ac:2348:AGENT2_CONFIG_FILE=`eval echo "${AGENT2_CONFIG_FILE}"` src/go/Makefile.am:18:AGENT_GOLDFLAGS += -X main.confDefault=${AGENT2_CONFIG_FILE} grep -RIn WEBSERVICE_CONFIG_FILE configure.ac:2028:WEBSERVICE_CONFIG_FILE="${sysconfdir}/zabbix_web_service.conf" configure.ac:2107:AC_SUBST(WEBSERVICE_CONFIG_FILE) configure.ac:2356:WEBSERVICE_CONFIG_FILE=`eval echo "${WEBSERVICE_CONFIG_FILE}"` configure.ac:2357:WEBSERVICE_CONFIG_FILE=`eval echo "${WEBSERVICE_CONFIG_FILE}"`