Add usecase and install example to readme

README.md

@@ -2,9 +2,19 @@
 
 This is an openwrt feed that contains definitions to include CoreDNS software into your OpenWRT build.
 
-## how to add the feed into your build
+## install from a binary
 
-> see for details: https://openwrt.org/docs/guide-developer/feeds
+### by using terminal
+1. download an ipk file from the releases page https://code.tokarch.uk/mainnika/openwrt-feed-coredns/releases
+2. put the file to the device, e.g. path `/tmp/coredns.ipk` use scp -- `scp coredns_1.8.6-1_arm_cortex-a7_neon-vfpv4.ipk root@[openwrt-ip]:/tmp/coredns.ipk`
+2. use opkg to install the downloaded file, e.g. `opkg install /tmp/coredns.ipk`
+
+### by using luci
+1. download an ipk file from the releases page https://code.tokarch.uk/mainnika/openwrt-feed-coredns/releases
+2. open luci admin gui and go `System` → `Software`
+3. use `Upload Package` buttom to upload local release file 
+
+## how to add the feed into your build
 
 1. open your feeds.conf.default and add the following line:
 
@@ -17,3 +27,51 @@ This is an openwrt feed that contains definitions to include CoreDNS software in
 3. install coredns packages into your build:
 
    `./scripts/feeds install -a -p feed_coredns`
+
+> see for details: https://openwrt.org/docs/guide-developer/feeds
+
+## service init
+
+The package setups an init script `/etc/init.d/coredns` and uci config section:
+
+```
+config coredns 'main'
+	option port '53'
+	option config '/etc/coredns/Corefile'
+```
+
+There are two options defined:
+- port, default: 53 -- a port where coredns will listen for connections
+- config, default: /etc/coredns/Corefile -- a Corefile config file
+
+> Use `uci` tool to change these values, e.g.: `uci set coredns.main.port=1053'
+
+## coredns configuration
+
+The package provides an empty config `Corefile` located at `/etc/coredns/Corefile`.
+The empty `Corefile`:
+
+```
+. { }
+```
+
+To configure the coredns instance properly set Corefile with your content.
+
+## use cases
+
+### openwrt hardware as the external dns resolver
+
+> I assume that in this setup openwrt act as a dhcp client (not a server).
+> You can set lan network as a dhcp client by using these uci values (use `uci commit` to apply):
+> ```
+> uci del network.lan.ipaddr
+> uci del network.lan.netmask
+> uci del network.lan.ip6assign
+> uci set network.lan.proto='dhcp'
+> ```
+
+the main goal is to replace `dnsmasq` with `coredns` because they share the same port `53`.
+
+1. go `System` → `Startup`, disable and stop `dnsmasq`
+2. enable and start `coredns`
+3. now coredns acts as a default resolver and listen all interfaces by default.

net/coredns/Makefile

@@ -42,7 +42,7 @@ define Package/coredns/install
 	$(INSTALL_BIN) ./files/coredns.init $(1)/etc/init.d/coredns
 
 	$(INSTALL_DIR) $(1)/etc/config
-	$(INSTALL_CONF) ./files/coredns.config $(1)/etc/config/coredns
+	$(INSTALL_CONF) ./files/coredns.conf $(1)/etc/config/coredns
 
 	$(INSTALL_DIR) $(1)/etc/coredns
 	$(INSTALL_CONF) ./files/Corefile $(1)/etc/coredns/Corefile