diff --git a/docker/headscale/prep.sh b/docker/headscale/prep.sh
index ee068f2..6a80b7d 100644
--- a/docker/headscale/prep.sh
+++ b/docker/headscale/prep.sh
@@ -36,4 +36,38 @@ download_and_process_config() {
     fi
 }
 
+insert_placeholders() {
+    local config_file="/etc/headscale/config-example.yaml"
+
+    if [[ ! -f "$config_file" ]]; then
+        echo "Config file $config_file not found."
+        return 1
+    fi
+
+    declare -a replacements=(
+        "server_url: .*" "server_url: \${SERVER_URL}"
+        "listen_addr: .*" "listen_addr: \${LISTEN_ADDR}"
+        "metrics_listen_addr: .*" "metrics_listen_addr: \${METRICS_LISTEN_ADDR}"
+        "grpc_listen_addr: .*" "grpc_listen_addr: \${GRPC_LISTEN_ADDR}"
+        "grpc_allow_insecure: .*" "grpc_allow_insecure: \${GRPC_ALLOW_INSECURE}"
+        "private_key_path: .*" "private_key_path: \${NOISE_PRIVATE_KEY_PATH}"
+        "acme_url: .*" "acme_url: \${ACME_URL}"
+        "acme_email: .*" "acme_email: \${ACME_EMAIL}"
+        "tls_letsencrypt_hostname: .*" "tls_letsencrypt_hostname: \${TLS_LETSENCRYPT_HOSTNAME}"
+        "tls_letsencrypt_cache_dir: .*" "tls_letsencrypt_cache_dir: \${TLS_LETSENCRYPT_CACHE_DIR}"
+        "db_type: .*" "db_type: \${DB_TYPE}"
+        "db_path: .*" "db_path: \${DB_PATH}"
+    )
+
+    for i in "${!replacements[@]}"; do
+        local search="${replacements[i]% *}"
+        local replace="${replacements[i]#* }"
+        sed -i "s|$search|$replace|" "$config_file"
+    done
+
+    echo "Placeholders inserted in $config_file"
+}
+
+insert_placeholders
+
 download_and_process_config
\ No newline at end of file