From a0f1ebdcb84815655ea612ef71232c97f2023c2f Mon Sep 17 00:00:00 2001
From: =?utf8?q?Konrad=20Ba=C5=84ka?= <k.banka@samsung.com>
Date: Mon, 25 Jan 2021 07:44:49 +0100
Subject: [PATCH] [COMMON][ETCD] Skip startup self-discovery for etcd nodes
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Current startup script of etcd checks whether all assumed other nodes
are already running, before proceeding. This check, however, also
includes checking localhost, but due to using headless service
statefulset pod DNS discovery, it doesnt succeed immediately.
In some deployments k8s DNS server may be laggy, thus failing startup
script to finish before liveness check. This patch fixes such failures
of 1 pod etcd clusters, and improves startup time for any size ones.

Signed-off-by: Konrad Bańka <k.banka@samsung.com>
Issue-ID: OOM-2668
Change-Id: I2f9263a0f4964b0a495631775d0cbbceef25e85b
---
 kubernetes/common/etcd/templates/statefulset.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kubernetes/common/etcd/templates/statefulset.yaml b/kubernetes/common/etcd/templates/statefulset.yaml
index c45648f757..3c7e3b002e 100644
--- a/kubernetes/common/etcd/templates/statefulset.yaml
+++ b/kubernetes/common/etcd/templates/statefulset.yaml
@@ -133,6 +133,10 @@ spec:
             # we should wait for other pods to be up before trying to join
             # otherwise we got "no such host" errors when trying to resolve other members
             for i in $(seq 0 $((${INITIAL_CLUSTER_SIZE} - 1))); do
+                if [ "${SET_NAME}-${i}" == "${HOSTNAME}" ]; then
+                    echo "Skipping self-checking"
+                    continue
+                fi
                 while true; do
                     echo "Waiting for ${SET_NAME}-${i}.${SERVICE_NAME} to come up"
                     ping -W 1 -c 1 ${SET_NAME}-${i}.${SERVICE_NAME} > /dev/null && break
-- 
2.16.6