Added the detection of docker or podman to start the node

start.sh

 #!/bin/bash
 
 trap 'exit 1' ERR
+flag_exit=0
+res='fail'
+cmd=''
 
-if ! which docker > /dev/null 2>&1
-then
-    echo 'Can not find Docker. Make sure it is installed.' >&2
+detect_cmd()
+{
+    if which $1 > /dev/null 2>&1; then
+        cmd=$1
+        res='success'
+    fi
+}
+
+detect_cmd 'podman'
+detect_cmd 'docker'
+
+if [[ $res = 'fail' ]]; then
+    echo 'Can not find any command to create containers (podman or docker).' >&2
     exit 1
 fi
 
@@ -24,14 +37,14 @@ else
 fi
 
 # Run this just a single time.
-# Docker itself makes sure it autostarts if it crashes or the server reboots.
-docker run                      \
-    --detach                    \
-    --restart=unless-stopped    \
-    --memory 4g                 \
-    $mounts                     \
-    -p 8545:8545                \
-    -p 8546:8546                \
-    -p 30303:30303              \
-    --name ${name}              \
-    bfaar/nodo:${tag}
+# Command itself makes sure it autostarts if it crashes or the server reboots.
+$cmd run                      \
+     --detach                    \
+     --restart=unless-stopped    \
+     --memory 4g                 \
+     $mounts                     \
+     -p 8545:8545                \
+     -p 8546:8546                \
+     -p 30303:30303              \
+     --name ${name}              \
+     bfaar/nodo:${tag}