From 5dd91c4bf2bc32680ebf6c2df7b053c266497016 Mon Sep 17 00:00:00 2001
From: Aakcht <aakcht@gmail.com>
Date: Wed, 4 Dec 2024 18:07:00 +0500
Subject: [PATCH] Use NSS_WRAPPER_PASSWD instead of /etc/passwd as in
 spark-operator image entrypoint.sh (#2312)

Signed-off-by: Aakcht <aakcht@gmail.com>
---
 entrypoint.sh | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/entrypoint.sh b/entrypoint.sh
index 0ca8730123..38ee7e9264 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -4,21 +4,23 @@
 set -ex
 
 # Check whether there is a passwd entry for the container UID
-uid=$(id -u)
-gid=$(id -g)
-
-# turn off -e for getent because it will return error code in anonymous uid case
-set +e
-uidentry=$(getent passwd $uid)
-set -e
-
-# If there is no passwd entry for the container UID, attempt to create one
-if [[ -z "$uidentry" ]] ; then
-    if [[ -w /etc/passwd ]] ; then
-        echo "$uid:x:$uid:$gid:anonymous uid:$SPARK_HOME:/bin/false" >> /etc/passwd
-    else
-        echo "Container ENTRYPOINT failed to add passwd entry for anonymous UID"
-    fi
+myuid="$(id -u)"
+# If there is no passwd entry for the container UID, attempt to fake one
+# You can also refer to the https://github.com/docker-library/official-images/pull/13089#issuecomment-1534706523
+# It's to resolve OpenShift random UID case.
+# See also: https://github.com/docker-library/postgres/pull/448
+if ! getent passwd "$myuid" &> /dev/null; then
+    for wrapper in {/usr,}/lib{/*,}/libnss_wrapper.so; do
+      if [ -s "$wrapper" ]; then
+        NSS_WRAPPER_PASSWD="$(mktemp)"
+        NSS_WRAPPER_GROUP="$(mktemp)"
+        export LD_PRELOAD="$wrapper" NSS_WRAPPER_PASSWD NSS_WRAPPER_GROUP
+        mygid="$(id -g)"
+        printf 'spark:x:%s:%s:${SPARK_USER_NAME:-anonymous uid}:%s:/bin/false\n' "$myuid" "$mygid" "$SPARK_HOME" > "$NSS_WRAPPER_PASSWD"
+        printf 'spark:x:%s:\n' "$mygid" > "$NSS_WRAPPER_GROUP"
+        break
+      fi
+    done
 fi
 
 exec /usr/bin/tini -s -- /usr/bin/spark-operator "$@"