docker-ce: add uci support for dockerd

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

utils/docker-ce/Makefile

@@ -49,6 +49,10 @@ define Package/docker-ce
   MENU:=1
 endef
 
+define Package/docker-ce/conffiles
+/etc/config/dockerd
+endef
+
 define Package/docker-ce/description
   Docker Engine is used by millions enables containerized applications
   to run anywhere consistently on any infrastructure.
@@ -123,6 +127,9 @@ define Package/docker-ce/install
 	$(INSTALL_DIR) $(1)/etc/docker
 	$(INSTALL_CONF) ./files/daemon.json $(1)/etc/docker/
 
+	$(INSTALL_DIR) $(1)/etc/config
+	$(INSTALL_CONF) ./files/etc/config/dockerd $(1)/etc/config/dockerd
+
 	# Must be after systcl 11-br-netfilter.conf from kmod-br-netfilter
 	$(INSTALL_DIR) $(1)/etc/sysctl.d
 	$(INSTALL_DATA) ./files/etc/sysctl.d/sysctl-br-netfilter-ip.conf \

utils/docker-ce/files/dockerd.init

@@ -3,12 +3,58 @@
 USE_PROCD=1
 START=25
 
+DOCKERD_CONF="/tmp/dockerd/daemon.json"
+
+json_add_array_string() {
+	json_add_string "" "$1"
+}
+
+process_config() {
+	local alt_config_file data_root log_level
+
+	rm -f "$DOCKERD_CONF"
+
+	[ -f /etc/config/dockerd ] || {
+		# Use the daemon default configuration
+		DOCKERD_CONF=""
+		return 0
+	}
+
+	config_load 'dockerd'
+
+	config_get alt_config_file globals alt_config_file
+	[ -n "$alt_config_file" ] && [ -f "$alt_config_file" ] && {
+		ln -s "$alt_config_file" "$DOCKERD_CONF"
+		return 0
+	}
+
+	config_get data_root globals data_root "/opt/docker/"
+	config_get log_level globals log_level "warn"
+
+	. /usr/share/libubox/jshn.sh
+	json_init
+	json_add_string "data-root" "$data_root"
+	json_add_string "log-level" "$log_level"
+	json_add_array "registry-mirrors"
+	config_list_foreach globals registry_mirror json_add_array_string
+	json_close_array
+
+	mkdir -p /tmp/dockerd
+	json_dump > "$DOCKERD_CONF"
+}
+
 start_service() {
 	local nofile=$(cat /proc/sys/fs/nr_open)
 
+	process_config
+
 	procd_open_instance
 	procd_set_param stderr 1
-	procd_set_param command /usr/bin/dockerd
+	if [ -z "$DOCKERD_CONF" ]; then
+		procd_set_param command /usr/bin/dockerd
+	else
+		procd_set_param command /usr/bin/dockerd --config-file="$DOCKERD_CONF"
+	fi
 	procd_set_param limits nofile="${nofile} ${nofile}"
 	procd_close_instance
 }

utils/docker-ce/files/etc/config/dockerd

@@ -0,0 +1,7 @@
+
+config globals 'globals'
+#	option alt_config_file "/etc/docker/daemon.json"
+	option data_root "/opt/docker/"
+	option log_level "warn"
+#	list registry_mirror "https://<my-docker-mirror-host>"
+#	list registry_mirror "https://hub.docker.com"