etcd: systemd unit support to start existing etcd node

Added etcd service and configuration file support to start etcd service
with existing cluster configuration.

Change-Id: Ia52bbf20fd1951aa76184da54af94231d2324888
Signed-off-by: ojayanth <ojayanth@in.ibm.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-extended/etcd/etcd/etcd-existing.conf

@@ -0,0 +1,37 @@
+# This is the configuration file to start the etcd server with
+# existing cluster configuration in the data directory.
+
+# Initial cluster state ('new' or 'existing').
+ETCD_INITIAL_CLUSTER_STATE='existing'
+
+# Path to the data directory.
+ETCD_DATA_DIR='/var/lib/etcd'
+
+# Time (in milliseconds) of a heartbeat interval.
+ETCD_HEARTBEAT_INTERVAL=100
+
+# Time (in milliseconds) for an election to timeout.
+ETCD_ELECTION_TIMEOUT=1000
+
+# List of comma separated URLs to listen on for peer traffic.
+ETCD_LISTEN_PEER_URLS=http://localhost:2380
+
+# List of comma separated URLs to listen on for client traffic.
+ETCD_LISTEN_CLIENT_URLS=http://localhost:2379
+
+# List of this member's peer URLs to advertise to the rest of the cluster.
+# The URLs needed to be a comma-separated list.
+ETCD_INITIAL_ADVERTISE_PEER_URLS=http://localhost:2380
+
+# List of this member's client URLs to advertise to the public.
+# The URLs needed to be a comma-separated list.
+ETCD_ADVERTISE_CLIENT_URLS=http://localhost:2379
+
+# Enable info-level logging for etcd.
+ETCD_LOG_LEVEL='info'
+
+# Specify 'stdout' or 'stderr' to skip journald logging even when running under systemd.
+ETCD_LOG_OUTPUTS='default'
+
+# etcd is not officially supported on arm64
+ETCD_UNSUPPORTED_ARCH='arm'

meta-oe/recipes-extended/etcd/etcd/etcd.service

@@ -0,0 +1,15 @@
+[Unit]
+Description=etcd key-value store
+Documentation=https://github.com/etcd-io/etcd
+After=network-online.target local-fs.target remote-fs.target time-sync.target
+Wants=network-online.target local-fs.target remote-fs.target time-sync.target
+ConditionPathExists=/var/lib/etcd/member
+
+[Service]
+Type=notify
+EnvironmentFile=/etc/etcd.d/etcd-existing.conf
+ExecStart=/usr/bin/etcd
+Restart=always
+
+[Install]
+WantedBy=multi-user.target

meta-oe/recipes-extended/etcd/etcd_3.5.7.bb

@@ -8,6 +8,8 @@ SRC_URI = " \
     git://github.com/etcd-io/etcd;branch=release-3.5;protocol=https \
     file://0001-xxhash-bump-to-v2.1.2.patch;patchdir=src/${GO_IMPORT} \
     file://0001-test_lib.sh-remove-gobin-requirement-during-build.patch;patchdir=src/${GO_IMPORT} \
+    file://etcd.service \
+    file://etcd-existing.conf \
 "
 
 SRCREV = "215b53cf3b48ee761f4c40908b3874b2e5e95e9f"
@@ -22,7 +24,7 @@ RDEPENDS:${PN}-dev = " \
 
 export GO111MODULE="on"
 
-inherit go
+inherit go systemd pkgconfig
 
 # Go based binaries do not handle being stripped
 INHIBIT_PACKAGE_STRIP = "1"
@@ -49,10 +51,19 @@ go_do_compile:prepend() {
     chmod u+w -R ${WORKDIR}/build/pkg/mod
 }
 
+REQUIRED_DISTRO_FEATURES = "systemd"
+SYSTEMD_PACKAGES = "${PN}"
+SYSTEMD_SERVICE:${PN}:append = " etcd.service"
+
 do_install:append() {
     install -d ${D}${bindir}/
     install -m 0755 ${D}/usr/lib/go/src/go.etcd.io/etcd/v3/bin/etcd ${D}${bindir}
     install -m 0755 ${D}/usr/lib/go/src/go.etcd.io/etcd/v3/bin/etcdctl ${D}${bindir}
     install -m 0755 ${D}/usr/lib/go/src/go.etcd.io/etcd/v3/bin/etcdutl ${D}${bindir}
+    install -m 0644 ${WORKDIR}/etcd-existing.conf -D -t ${D}${sysconfdir}/etcd.d
+    install -d ${D}${systemd_system_unitdir}
+    install -m 0644 ${WORKDIR}/etcd.service ${D}${systemd_system_unitdir}/
 }
 
+FILES:${PN}:append = " ${sysconfdir}/etcd.d/etcd-existing.conf"
+