fix migration script (#143)

- remove new line char from etcd get
- remove key name from etcd get
- -i flag required on kubectl exec
- correct version numbers in comments

Co-authored-by: Arnaud Meyer <arnaud.meyer@idealo.de>

scripts/migrate_etcd_0.1_0.2.sh

@@ -2,9 +2,17 @@
 
 set -exo pipefail
 
+TMP=$(mktemp)
+
+function cleanup() {
+  rm -f "$TMP"
+}
+
+trap cleanup EXIT
+
 if [[ "$1" == "-h" || -z "$ETCD_NS" || -z "$ETCD_POD" || -z "$M3DB_NS" || -z "$M3DB_CLUSTER" ]]; then
-  echo "Script for migrating etcd data from m3db-operator 0.2 -> 0.3"
-  echo "Usage: ETCD_NS=<namespace> ETCD_POD=<pod> M3DB_NS=<namespace> M3DB_CLUSTER=<cluster_name> ./migrate_etcd_0.2_0.3.sh"
+  echo "Script for migrating etcd data from m3db-operator 0.1 -> 0.2"
+  echo "Usage: ETCD_NS=<namespace> ETCD_POD=<pod> M3DB_NS=<namespace> M3DB_CLUSTER=<cluster_name> ./migrate_etcd_0.1_0.2.sh"
   exit 0
 fi
 
@@ -19,5 +27,17 @@ fi
 ENV="$NS/$CLUSTER"
 echo "Copying namespace and placement data from env=default_env to env=$ENV"
 
-kubectl exec -n "$ETCD_NS" "$ETCD_POD" -- env ETCDCTL_API=3 etcdctl get _sd.placement/default_env/m3db | kubectl exec -n "$ETCD_NS" "$ETCD_POD" -- env ETCDCTL_API=3 etcdctl put "_sd.placement/$ENV/m3db"
-kubectl exec -n "$ETCD_NS" "$ETCD_POD" -- env ETCDCTL_API=3 etcdctl get _kv/default_env/m3db.node.namespaces | kubectl exec -n "$ETCD_NS" "$ETCD_POD" -- env ETCDCTL_API=3 etcdctl put "_kv/$ENV/m3db.node.namespaces"
+
+# Put placement bytes (includes trailing newline) into TMP
+kubectl exec -n "$ETCD_NS" "$ETCD_POD" -- env ETCDCTL_API=3 etcdctl get --print-value-only _sd.placement/default_env/m3db > "$TMP"
+
+# Trim newline in a cross-platform (OSX + Linux) manner and put in new key
+N=$(<"$TMP" wc -c)
+N=$((N-1))
+head -c "$N" "$TMP" | kubectl exec -i -n "$ETCD_NS" "$ETCD_POD" -- env ETCDCTL_API=3 etcdctl put "_sd.placement/$ENV/m3db"
+
+# Repeat for namespaces
+kubectl exec -n "$ETCD_NS" "$ETCD_POD" -- env ETCDCTL_API=3 etcdctl get --print-value-only _kv/default_env/m3db.node.namespaces > "$TMP"
+N=$(<"$TMP" wc -c)
+N=$((N-1))
+head -c "$N" "$TMP" | kubectl exec -i -n "$ETCD_NS" "$ETCD_POD" -- env ETCDCTL_API=3 etcdctl put "_kv/$ENV/m3db.node.namespaces"