From 91c3804959e75c8425b865b09f7d5f216d99200f Mon Sep 17 00:00:00 2001
From: Dan Mihai <dmihai@microsoft.com>
Date: Thu, 18 Sep 2025 22:20:14 +0000
Subject: [PATCH] tests: k8s: add container_exec_with_retries()

Add container_exec_with_retries(), useful for retrying if needed
commands similar to:

kubectl exec <pod_name> -c <container_name> -- <command>

Signed-off-by: Dan Mihai <dmihai@microsoft.com>
---
 tests/integration/kubernetes/tests_common.sh | 42 ++++++++++++++++++--
 1 file changed, 38 insertions(+), 4 deletions(-)

diff --git a/tests/integration/kubernetes/tests_common.sh b/tests/integration/kubernetes/tests_common.sh
index 5b79908690..7d254d7d75 100644
--- a/tests/integration/kubernetes/tests_common.sh
+++ b/tests/integration/kubernetes/tests_common.sh
@@ -454,17 +454,51 @@ grep_pod_exec_output() {
 pod_exec_with_retries() {
 	local -r pod_name="$1"
 	shift
+	local -r container_name=""
+
+	container_exec_with_retries "${pod_name}" "${container_name}" "$@"
+}
+
+# Execute a command in a pod's container and echo kubectl's output to stdout.
+#
+# If the caller specifies an empty container name as parameter, the command is executed in pod's default container,
+# or in pod's first container if there is no default.
+#
+# This function retries "kubectl exec" several times, if:
+# - kubectl returns a failure exit code, or
+# - kubectl exits successfully but produces empty console output.
+# These retries are an attempt to work around issues similar to https://github.com/kubernetes/kubernetes/issues/124571.
+#
+# Parameters:
+#	$1	- pod name
+#	$2	- container name
+#	$3+	- the command to execute using "kubectl exec"
+#
+# Exit code:
+#	0
+container_exec_with_retries() {
+	local -r pod_name="$1"
+	shift
+	local -r container_name="$1"
+	shift
 	local cmd_out=""
 
 	for _ in {1..10}; do
-		bats_unbuffered_info "Executing in pod ${pod_name}: $*"
-		cmd_out=$(kubectl exec "${pod_name}" -- "$@") || (bats_unbuffered_info "kubectl exec failed" ; cmd_out="")
+		if [[ -n "${container_name}" ]]; then
+			bats_unbuffered_info "Executing in pod ${pod_name}, container ${container_name}: $*"
+			cmd_out=$(kubectl exec "${pod_name}" -c "${container_name}" -- "$@") || (bats_unbuffered_info "kubectl exec failed" ; cmd_out="")
+		else
+			bats_unbuffered_info "Executing in pod ${pod_name}: $*"
+			cmd_out=$(kubectl exec "${pod_name}" -- "$@") || (bats_unbuffered_info "kubectl exec failed" ; cmd_out="")
+		fi
+
 		if [[ -n "${cmd_out}" ]]; then
 			bats_unbuffered_info "command output: ${cmd_out}"
 			break
+		else
+			bats_unbuffered_info "Warning: empty output from kubectl exec"
+			sleep 1
 		fi
-		bats_unbuffered_info "Warning: empty output from kubectl exec"
-		sleep 1
 	done
 
 	echo "${cmd_out}"