feat(dev-db): coordinate with the c10n service

this is an experiment to coordinate etcd with c10n.

sdk_container/src/third_party/coreos-overlay/dev-db/etcd/etcd-0.0.1.ebuild

@@ -31,6 +31,9 @@ src_compile() {
 
 src_install() {
 	dobin ${S}/${PN}
+	dobin ${FILESDIR}/coreos-c10n
+	dobin ${FILESDIR}/etcd-bootstrap
+
 	systemd_dounit "${FILESDIR}"/${PN}.service
 	systemd_enable_service multi-user.target ${PN}.service
 }

sdk_container/src/third_party/coreos-overlay/dev-db/etcd/etcd-99999.ebuild

@@ -29,7 +29,10 @@ src_compile() {
 }
 
 src_install() {
-	dosbin ${S}/${PN}
+	dobin ${S}/${PN}
+	dobin ${FILESDIR}/coreos-c10n
+	dobin ${FILESDIR}/etcd-bootstrap
+
 	systemd_dounit "${FILESDIR}"/${PN}.service
 	systemd_enable_service multi-user.target ${PN}.service
 }

sdk_container/src/third_party/coreos-overlay/dev-db/etcd/files/coreos-c10n

@@ -32,4 +32,4 @@ for IP4 in `curl -s $META_URL/meta-data/ | grep ipv4`; do
         fi
 done
 
-curl $C10N_ENDPOINT -d "c10n_url=$URL" -d"ip_list=$IP_LIST"
+curl $C10N_ENDPOINT -d "c10n_url=$URL" -d"ip_list=$IP_LIST" > /var/run/etcd/bootstrap.config

sdk_container/src/third_party/coreos-overlay/dev-db/etcd/files/etcd-bootstrap

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+# Test an IP address for validity:
+# Usage:
+#      valid_ip IP_ADDRESS
+#      if [[ $? -eq 0 ]]; then echo good; else echo bad; fi
+#   OR
+#      if valid_ip IP_ADDRESS; then echo good; else echo bad; fi
+# http://www.linuxjournal.com/content/validating-ip-address-bash-script
+function valid_ip()
+{
+    local  ip=$1
+    local  stat=1
+
+    if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
+        OIFS=$IFS
+        IFS='.'
+        ip=($ip)
+        IFS=$OIFS
+        [[ ${ip[0]} -le 255 && ${ip[1]} -le 255 \
+            && ${ip[2]} -le 255 && ${ip[3]} -le 255 ]]
+        stat=$?
+    fi
+    return $stat
+}
+
+BOOTSTRAP="/var/run/etcd/bootstrap.config"
+for HOSTS in `[ -e $BOOTSTRAP ] && cat $BOOTSTRAP`; do
+        for IP in `echo $HOSTS | sed 's/,/\'$'\n/g' `; do
+                echo $IP
+                LEADER=`curl --connect-timeout 1 -s $IP:7001/leader`
+                if [ $? -eq 0 ]; then
+                        LEADER_IP=`echo $LEADER | cut -d':' -f1`
+                        LEADER_PORT=`echo $LEADER | cut -d':' -f2`
+                        if valid_ip $LEADER_IP; then
+                                echo GOT LEADER $LEADER
+                                exec /usr/bin/etcd -i -C $LEADER
+                        fi
+                fi
+        done
+done
+echo "Not able to connect to a leader, just starting..."
+exec /usr/bin/etcd -i

sdk_container/src/third_party/coreos-overlay/dev-db/etcd/files/etcd.service

@@ -1,4 +1,6 @@
 [Service]
+ExecStartPre=-/bin/mkdir -p /var/run/etcd
+ExecStartPre=/usr/bin/coreos-c10n
 ExecStart=/usr/bin/etcd-bootstrap
 
 [Install]