After container starts, wait for systemd to start for every detached one (#2965)

core_dumps/docker-awaiter.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+
+DOCKER_IMAGE=$1
+
+zhdun()
+{
+    command=$1
+    expected_result=$2
+    waiting_message=$3
+    retries=$4
+    sleep_delay=$5
+    result=$($command)
+    result="${result%%[[:cntrl:]]}"
+    retries_counter=1
+
+    while true;
+    do
+        if [ "$result" != "$expected_result" ]; then
+            echo $waiting_message " Status: " $result ", attempt: " $retries_counter
+            sleep $sleep_delay
+        else
+            echo Finished waiting for \'"$command"\' to return \'"$expected_result"\'
+            exit
+        fi
+
+        if [ $retries_counter -ge $retries ]; then
+            echo "Tired to wait for retry, $retries_counter attemps were made"
+            exit
+        fi
+        retries_counter=$(($retries_counter + 1))
+    done
+}
+
+check_result="running"
+check_command="docker exec -t $DOCKER_IMAGE systemctl is-system-running"
+waiting_message="Waiting for docker container to start systemd."
+
+zhdun "$check_command" "$check_result" "$waiting_message" 60 2