diff --git a/tests/run b/tests/run
index f28e2f8..de0123f 100755
--- a/tests/run
+++ b/tests/run
@@ -1,58 +1,78 @@
 #!/bin/bash
 # See: https://github.com/kward/shunit2
+# Usage: tests/run [OPTION]... IMAGE_NAME
+# Options: --verbose --no-cleanup
+# Example: tests/run atmoz/sftp:alpine
+
+# Booleans
+OPTION_TRUE=0
+OPTION_FALSE=1
+
+# Options
+OPTION_VERBOSE="${OPTION_VERBOSE:-"$OPTION_FALSE"}"
+OPTION_CLEANUP="${OPTION_CLEANUP:-"$OPTION_TRUE"}"
+
+# ARGUMENTS:
+while [ "$#" -ge 1 ]; do
+    case "$1" in
+        --verbose) OPTION_VERBOSE="$OPTION_TRUE"; shift ;;
+        --no-cleanup) OPTION_VERBOSE="$OPTION_FALSE"; shift ;;
+        --) break ;; # rest of arguments goes to shunit2
+        --*) echo "Unknown argument: $1"; exit 2 ;;
+        *) imageName="$1"; shift ;;
+    esac
+done
 
-argImage=$1
-argOutput=${2:-"quiet"}
-argCleanup=${3:-"cleanup"}
 testDir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
-imageName="$argImage"
 tmpDir="$(mktemp -d /tmp/atmoz_sftp_XXXX)"
 sshKeyPri="$tmpDir/rsa"
 sshKeyPub="$tmpDir/rsa.pub"
 sshHostEd25519Key="$tmpDir/ssh_host_ed25519_key"
 sshHostKeyMountArg="--volume=$sshHostEd25519Key:/etc/ssh/ssh_host_ed25519_key"
 sshKnownHosts="$tmpDir/known_hosts"
+runArgs=("-P" "--network=private" "$sshHostKeyMountArg")
 
-if [ $UID != 0 ] && ! groups | grep -qw docker; then
-    echo "Run with sudo/root or add user $USER to group 'docker'"
-    exit 1
+# podman or docker
+if [ -z "$CONTAINER_ENGINE" ]; then
+    if type podman &>/dev/null; then
+        CONTAINER_ENGINE="podman"
+    else
+        CONTAINER_ENGINE="docker"
+    fi
 fi
 
 if [ ! -f "$testDir/shunit2/shunit2" ]; then
-    echo "Could not find shunit2 in $testDir/shunit2."
+    echo "Could not find shunit2 in $testDir/shunit2"
     echo "Run 'git submodule update --init'"
     exit 2
 fi
 
-if [ -z "$argImage" ]; then
-    echo "Missing image name"
+if [ -z "$imageName" ]; then
+    echo "Missing name of image you want to run tests against"
     exit 3
 fi
 
-if [ "$argOutput" == "quiet" ]; then
-    redirect="/dev/null"
-else
+if [ "$OPTION_VERBOSE" == "$OPTION_TRUE" ]; then
     redirect="/dev/stdout"
+else
+    redirect="/dev/null"
 fi
 
-# clear argument list (or shunit2 will try to use them)
-set --
-
 ##############################################################################
-## Helper functions
+## Setup: shunit2 functions
 ##############################################################################
 
 function oneTimeSetUp() {
     # Generate temporary ssh keys for testing
     if [ ! -f "$sshKeyPri" ]; then
-        ssh-keygen -t rsa -f "$sshKeyPri" -N '' > "$redirect" 2>&1
+        ssh-keygen -t rsa -f "$sshKeyPri" -N '' < /dev/null > "$redirect" 2>&1
     fi
 
     # Private key can not be read by others (sshd will complain)
     chmod go-rw "$sshKeyPri"
 
     # Generate host key
-    ssh-keygen -t ed25519 -f "$sshHostEd25519Key" < /dev/null
+    ssh-keygen -t ed25519 -f "$sshHostEd25519Key" -N '' < /dev/null
 }
 
 function setUp() {
@@ -67,34 +87,41 @@ function setUp() {
 function tearDown() {
     retireContainer "$containerName"
 
-    if [ "$argCleanup" == "cleanup" ] && [ -d "$containerTmpDir" ]; then
+    if [ "$OPTION_CLEANUP" == "$OPTION_TRUE" ] && [ -d "$containerTmpDir" ]; then
         rm -rf "$containerTmpDir" || true # Can fail on GitHub Actions
     fi
 }
 
+##############################################################################
+## Helper functions
+##############################################################################
+
+function container() {
+    "$CONTAINER_ENGINE" "$@"
+}
 function retireContainer() {
-    if [ "$(docker ps -qaf name="$1")" ]; then
-        if [ "$argOutput" != "quiet" ]; then
-            echo "Docker log for $1:"
-            docker logs "$1"
+    if [ "$(container ps -qaf name="$1")" ]; then
+        if [ "$OPTION_VERBOSE" == "$OPTION_TRUE" ]; then
+            echo "container log for $1:"
+            container logs "$1"
         fi
 
-        if [ "$argCleanup" == "cleanup" ]; then
-            docker rm -fv "$1" > "$redirect" 2>&1
+        if [ "$OPTION_CLEANUP" == "$OPTION_TRUE" ]; then
+            container rm -fv "$1" > "$redirect" 2>&1
         fi
     fi
 }
 
-function getSftpIp() {
-    docker inspect -f "{{.NetworkSettings.IPAddress}}" "$1"
+function getSftpPort() {
+    container container port "$1" | cut -d: -f2 | head -1
 }
 
 function runSftpCommands() {
-    ip="$(getSftpIp "$1")"
+    port="$(getSftpPort "$1")"
     user="$2"
     shift 2
 
-    echo "$ip $(cat "$sshHostEd25519Key.pub")" >> "$sshKnownHosts"
+    echo "127.0.0.1 $(cat "$sshHostEd25519Key.pub")" >> "$sshKnownHosts"
 
     commands=""
     for cmd in "$@"; do
@@ -104,7 +131,7 @@ function runSftpCommands() {
     echo "$commands" | sftp \
         -i "$sshKeyPri" \
         -oUserKnownHostsFile="$sshKnownHosts" \
-        -b - "$user@$ip" \
+        -b - -P "$port" "$user@127.0.0.1" \
         > "$redirect" 2>&1
 
     status=$?
@@ -113,17 +140,19 @@ function runSftpCommands() {
 }
 
 function waitForServer() {
-    containerName="$1"
-    echo -n "Waiting for $containerName to open port 22 ..."
+    local containerName="$1"
+    local port
+
+    echo -n "Waiting for $containerName to open a port ..."
 
     for _ in {1..30}; do
-        sleep 1
-        ip="$(getSftpIp "$containerName")"
         echo -n "."
-        if [ -n "$ip" ] && nc -z "$ip" 22; then
-            echo " OPEN"
+        port="$(getSftpPort "$containerName")"
+        if [ -n "$port" ] && ssh-keyscan -4 -T 1 -p "$port" "127.0.0.1" &>/dev/null; then
+            echo " PORT $port OPEN"
             return 0;
         fi
+        sleep 0.5
     done
 
     echo " TIMEOUT"
@@ -135,7 +164,7 @@ function waitForServer() {
 ##############################################################################
 
 function testSmallestUserConfig() {
-    docker run --name "$containerName" "$sshHostKeyMountArg" \
+    container run --name "$containerName" "${runArgs[@]}" \
         --entrypoint="/bin/sh" \
         "$imageName" \
         -c "create-sftp-user u: && id u" \
@@ -144,7 +173,7 @@ function testSmallestUserConfig() {
 }
 
 function testCreateUserWithDot() {
-    docker run --name "$containerName" "$sshHostKeyMountArg" \
+    container run --name "$containerName" "${runArgs[@]}" \
         --entrypoint="/bin/sh" \
         "$imageName" \
         -c "create-sftp-user user.with.dot: && id user.with.dot" \
@@ -153,7 +182,7 @@ function testCreateUserWithDot() {
 }
 
 function testUserCustomUidAndGid() {
-    id="$(docker run --name "$containerName" "$sshHostKeyMountArg" \
+    id="$(container run --name "$containerName" "${runArgs[@]}" \
         --entrypoint="/bin/sh" \
         "$imageName" \
         -c "create-sftp-user u::1234:4321: > /dev/null && id u" )"
@@ -169,14 +198,14 @@ function testUserCustomUidAndGid() {
 }
 
 function testCommandPassthrough() {
-    docker run --name "$containerName" "$sshHostKeyMountArg" \
+    container run --name "$containerName" "${runArgs[@]}" \
         "$imageName" test 1 -eq 1 \
         > "$redirect" 2>&1
     assertTrue "command passthrough" $?
 }
 
 function testUsersConf() {
-    docker run --name "$containerName" "$sshHostKeyMountArg" -d \
+    container run --name "$containerName" "${runArgs[@]}" -d \
         -v "$testDir/files/users.conf:/etc/sftp/users.conf:ro" \
         "$imageName" \
         > "$redirect" 2>&1
@@ -184,21 +213,21 @@ function testUsersConf() {
     waitForServer "$containerName"
     assertTrue "waitForServer" $?
 
-    docker exec "$containerName" id user-from-conf > /dev/null
+    container exec "$containerName" id user-from-conf > /dev/null
     assertTrue "user-from-conf" $?
 
-    docker exec "$containerName" id test > /dev/null
+    container exec "$containerName" id test > /dev/null
     assertTrue "test" $?
 
-    docker exec "$containerName" id user.with.dot > /dev/null
+    container exec "$containerName" id user.with.dot > /dev/null
     assertTrue "user.with.dot" $?
 
-    docker exec "$containerName" test -d /home/test/dir1 -a -d /home/test/dir2
+    container exec "$containerName" test -d /home/test/dir1 -a -d /home/test/dir2
     assertTrue "dirs exists" $?
 }
 
 function testLegacyUsersConf() {
-    docker run --name "$containerName" "$sshHostKeyMountArg" -d \
+    container run --name "$containerName" "${runArgs[@]}" -d \
         -v "$testDir/files/users.conf:/etc/sftp-users.conf:ro" \
         "$imageName" \
         > "$redirect" 2>&1
@@ -206,12 +235,12 @@ function testLegacyUsersConf() {
     waitForServer "$containerName"
     assertTrue "waitForServer" $?
 
-    docker exec "$containerName" id user-from-conf > /dev/null
+    container exec "$containerName" id user-from-conf > /dev/null
     assertTrue "user-from-conf" $?
 }
 
 function testCreateUsersUsingEnv() {
-    docker run --name "$containerName" "$sshHostKeyMountArg" -d \
+    container run --name "$containerName" "${runArgs[@]}" -d \
         -e "SFTP_USERS=user-from-env: user-from-env-2:" \
         "$imageName" \
         > "$redirect" 2>&1
@@ -219,15 +248,15 @@ function testCreateUsersUsingEnv() {
     waitForServer "$containerName"
     assertTrue "waitForServer" $?
 
-    docker exec "$containerName" id user-from-env > /dev/null
+    container exec "$containerName" id user-from-env > /dev/null
     assertTrue "user-from-env" $?
 
-    docker exec "$containerName" id user-from-env-2 > /dev/null
+    container exec "$containerName" id user-from-env-2 > /dev/null
     assertTrue "user-from-env-2" $?
 }
 
 function testCreateUsersUsingCombo() {
-    docker run --name "$containerName" "$sshHostKeyMountArg" -d \
+    container run --name "$containerName" "${runArgs[@]}" -d \
         -v "$testDir/files/users.conf:/etc/sftp-users.conf:ro" \
         -e "SFTP_USERS=user-from-env:" \
         "$imageName" \
@@ -237,18 +266,18 @@ function testCreateUsersUsingCombo() {
     waitForServer "$containerName"
     assertTrue "waitForServer" $?
 
-    docker exec "$containerName" id user-from-conf > /dev/null
+    container exec "$containerName" id user-from-conf > /dev/null
     assertTrue "user-from-conf" $?
 
-    docker exec "$containerName" id user-from-env > /dev/null
+    container exec "$containerName" id user-from-env > /dev/null
     assertTrue "user-from-env" $?
 
-    docker exec "$containerName" id user-from-cmd > /dev/null
+    container exec "$containerName" id user-from-cmd > /dev/null
     assertTrue "user-from-cmd" $?
 }
 
 function testWriteAccessToAutocreatedDirs() {
-    docker run --name "$containerName" "$sshHostKeyMountArg" -d \
+    container run --name "$containerName" "${runArgs[@]}" -d \
         -v "$sshKeyPub":/home/test/.ssh/keys/id_rsa.pub:ro \
         "$imageName" "test::::testdir,dir with spaces" \
         > "$redirect" 2>&1
@@ -264,18 +293,19 @@ function testWriteAccessToAutocreatedDirs() {
         "exit"
     assertTrue "runSftpCommands" $?
 
-    docker exec "$containerName" test -d /home/test/testdir/test
+    container exec "$containerName" test -d /home/test/testdir/test
     assertTrue "testdir write access" $?
 
-    docker exec "$containerName" test -d "/home/test/dir with spaces/test"
+    container exec "$containerName" test -d "/home/test/dir with spaces/test"
     assertTrue "dir with spaces write access" $?
 }
 
 function testWriteAccessToLimitedChroot() {
     # Modified sshd_config with chrooted home subdir
     tmpConfig="$(mktemp)"
-    sed 's/^ChrootDirectory.*/ChrootDirectory %h\/sftp/' \
-        < "$testDir/../files/sshd_config" > "$tmpConfig"
+    container run --rm --entrypoint=bash "$imageName" -c "cat /etc/ssh/sshd_config" |
+        sed 's/^ChrootDirectory.*/ChrootDirectory %h\/sftp/' \
+        > "$tmpConfig"
 
     # Set correct permissions on chroot
     tmpScript="$(mktemp)"
@@ -286,7 +316,7 @@ chmod 755 /home/*/sftp
 EOF
     chmod +x "$tmpScript"
 
-    docker run --name "$containerName" "$sshHostKeyMountArg" -d \
+    container run --name "$containerName" "${runArgs[@]}" -d \
         -v "$sshKeyPub":/home/test/.ssh/keys/id_rsa.pub:ro \
         -v "$tmpConfig:/etc/ssh/sshd_config" \
         -v "$tmpScript:/etc/sftp.d/limited_home_dir" \
@@ -302,7 +332,7 @@ EOF
         "exit"
     assertTrue "runSftpCommands" $?
 
-    docker exec "$containerName" test -d /home/test/sftp/upload/test
+    container exec "$containerName" test -d /home/test/sftp/upload/test
     assertTrue "limited chroot write access" $?
 }
 
@@ -314,7 +344,7 @@ function testBindmountDirScript() {
         > "$containerTmpDir/mount.sh"
     chmod +x "$containerTmpDir/mount.sh"
 
-    docker run --name "$containerName" "$sshHostKeyMountArg" -d \
+    container run --name "$containerName" "${runArgs[@]}" -d \
         --privileged=true \
         -v "$sshKeyPub":/home/custom/.ssh/keys/id_rsa.pub:ro \
         -v "$containerTmpDir/custom/bindmount":/custom \
@@ -331,12 +361,12 @@ function testBindmountDirScript() {
         "exit"
     assertTrue "runSftpCommands" $?
 
-    docker exec "$containerName" test -d /home/custom/bindmount/test
+    container exec "$containerName" test -d /home/custom/bindmount/test
     assertTrue "directory exist" $?
 }
 
 function testDuplicateSshKeys() {
-    docker run --name "$containerName" "$sshHostKeyMountArg" -d \
+    container run --name "$containerName" "${runArgs[@]}" -d \
         -v "$sshKeyPub":/home/user/.ssh/keys/key1.pub:ro \
         -v "$sshKeyPub":/home/user/.ssh/keys/key2.pub:ro \
         "$imageName" "user:" \
@@ -345,7 +375,7 @@ function testDuplicateSshKeys() {
     waitForServer "$containerName"
     assertTrue "waitForServer" $?
 
-    lines="$(docker exec "$containerName" sh -c \
+    lines="$(container exec "$containerName" sh -c \
         "wc -l < /home/user/.ssh/authorized_keys")"
     assertEquals "1" "$lines"
 }