diff --git a/ci/ci-debian.Dockerfile b/ci/ci-debian.Dockerfile
index 7d9aeaf40..a904431a4 100644
--- a/ci/ci-debian.Dockerfile
+++ b/ci/ci-debian.Dockerfile
@@ -4,7 +4,8 @@ ARG BASE_TEST_IMAGE=test-code
 FROM debian:${DEBIAN_CODENAME}-slim as base
 ARG DEBIAN_CODENAME
 
-ENV CI_RUNNING=true TERM=xterm
+ENV CI_RUNNING=true TERM=xterm DEBIAN_FRONTEND=noninteractive
+RUN 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selections
 
 # create pi configs to test installation
 RUN touch /boot/config.txt
diff --git a/ci/installation/run_install_faststartup.sh b/ci/installation/run_install_faststartup.sh
index 1cefbc8be..a9354cf49 100644
--- a/ci/installation/run_install_faststartup.sh
+++ b/ci/installation/run_install_faststartup.sh
@@ -5,13 +5,9 @@
 
 # Objective: Test installation with script using a simple configuration
 
-local_install_script_path="${INSTALL_SCRIPT_PATH:-./../../installation/}"
-local_install_script_path="${local_install_script_path%/}"
-
-# Preparations
-# No interactive frontend
-export DEBIAN_FRONTEND=noninteractive
-echo 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selections
+SOURCE="${BASH_SOURCE[0]}"
+SCRIPT_DIR="$(dirname "$SOURCE")"
+INSTALL_SCRIPT_PATH="${SCRIPT_DIR}/../../installation"
 
 # Run installation (in interactive mode)
 # y - start setup
@@ -28,7 +24,7 @@ echo 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selecti
 # - - install node (only with WebApp = y)
 # n - reboot
 
-"$local_install_script_path"/install-jukebox.sh <<< 'y
+"${INSTALL_SCRIPT_PATH}/install-jukebox.sh" <<< 'y
 y
 y
 n
diff --git a/ci/installation/run_install_test.sh b/ci/installation/run_install_test.sh
index 6f2f07fdd..fc6c817a1 100644
--- a/ci/installation/run_install_test.sh
+++ b/ci/installation/run_install_test.sh
@@ -5,13 +5,9 @@
 
 # Objective: Test installation with script using a simple configuration
 
-local_install_script_path="${INSTALL_SCRIPT_PATH:-./../../installation/}"
-local_install_script_path="${local_install_script_path%/}"
-
-# Preparations
-# No interactive frontend
-export DEBIAN_FRONTEND=noninteractive
-echo 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selections
+SOURCE="${BASH_SOURCE[0]}"
+SCRIPT_DIR="$(dirname "$SOURCE")"
+INSTALL_SCRIPT_PATH="${SCRIPT_DIR}/../../installation"
 
 # Run installation (in interactive mode)
 # y - start setup
@@ -29,7 +25,7 @@ echo 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selecti
 # y - install node
 # n - reboot
 
-"$local_install_script_path"/install-jukebox.sh <<< 'y
+"${INSTALL_SCRIPT_PATH}/install-jukebox.sh" <<< 'y
 n
 n
 y
diff --git a/ci/installation/run_install_user_not_pi.sh b/ci/installation/run_install_user_not_pi.sh
index 02cf2734c..8dda5887e 100644
--- a/ci/installation/run_install_user_not_pi.sh
+++ b/ci/installation/run_install_user_not_pi.sh
@@ -5,18 +5,14 @@
 
 # Objective: Test installation with script using a simple configuration
 
-local_install_script_path="${INSTALL_SCRIPT_PATH:-./../../installation/}"
-local_install_script_path="${local_install_script_path%/}"
-
-# Preparations
-# No interactive frontend
-export DEBIAN_FRONTEND=noninteractive
-echo 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selections
+SOURCE="${BASH_SOURCE[0]}"
+SCRIPT_DIR="$(dirname "$SOURCE")"
+INSTALL_SCRIPT_PATH="${SCRIPT_DIR}/../../installation"
 
 # Run installation (in interactive mode)
 # - - Installation must abort early
 
-"$local_install_script_path"/install-jukebox.sh
+"${INSTALL_SCRIPT_PATH}/install-jukebox.sh"
 INSTALLATION_EXITCODE=$?
 
 # only count abortion due to "not user pi" as success
diff --git a/ci/installation/run_install_webapp.sh b/ci/installation/run_install_webapp.sh
index cc36fdeaf..15dae20b1 100644
--- a/ci/installation/run_install_webapp.sh
+++ b/ci/installation/run_install_webapp.sh
@@ -5,13 +5,9 @@
 
 # Objective: Test installation with script using a simple configuration
 
-local_install_script_path="${INSTALL_SCRIPT_PATH:-./../../installation/}"
-local_install_script_path="${local_install_script_path%/}"
-
-# Preparations
-# No interactive frontend
-export DEBIAN_FRONTEND=noninteractive
-echo 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selections
+SOURCE="${BASH_SOURCE[0]}"
+SCRIPT_DIR="$(dirname "$SOURCE")"
+INSTALL_SCRIPT_PATH="${SCRIPT_DIR}/../../installation"
 
 # Run installation (in interactive mode)
 # y - start setup
@@ -28,7 +24,7 @@ echo 'debconf debconf/frontend select Noninteractive' | sudo debconf-set-selecti
 # y - install node
 # n - reboot
 
-"$local_install_script_path"/install-jukebox.sh <<< 'y
+"${INSTALL_SCRIPT_PATH}/install-jukebox.sh" <<< 'y
 n
 n
 n