Added tests.sh script, Makefile and updated documentation

tests.sh

@@ -0,0 +1,89 @@
+#!/bin/bash
+# Unit tests for backup.sh
+# This tool is NOT intended to be used outside
+# of a testing environment, please use at your own risk.
+# By Marco Cetica 2023 (<email@marcocetica.com>)
+#
+
+set -e
+
+helper() {
+    cat <<EOF
+backup.sh unit testing suite.
+Do **NOT** use this tool outside of a testing environment.
+
+This tool creates a lot of dummy files to emulate a real production
+environment. Any file inside the following directories will be overwritten:
+    - /var/log
+    - /var/www
+    - /etc/nginx
+    - /etc/ssh
+
+Please, use at your own risk.
+To acknowledge that, run again this tool with 'I_HAVE_READ_THE_HELPER' as a parameter.
+EOF
+}
+
+create_files() {
+    mkdir -p /etc/{ssh,nginx}
+    mkdir -p /var/{www,log}
+
+    touch /etc/ssh/{ssh_config,sshd_config,moduli,ssh_host_dsa_key}
+    touch /etc/nginx/{nginx.conf,fastcgi.conf,mime.types}
+    touch /var/www/{index.html,style.css,logic.js}
+    touch /var/log/{access.log,error.log,lastlog,messages}
+
+    for file in ssh_config sshd_config moduli ssh_host_dsa_key ; do
+        head -c 1M </dev/random > /etc/ssh/$file
+    done
+
+    for file in index.html style.css logic.js ; do
+        head -c 1M </dev/random > /var/www/$file
+    done
+
+    for file in nginx.conf fastcgi.conf mime.types ; do
+        head -c 1M </dev/random > /etc/nginx/$file
+    done
+
+    for file in access.log error.log lastlog messages ; do
+        head -c 1M </dev/random > /var/log/$file
+    done
+}
+
+execute_backup() {
+    ./backup.sh -b backup_sources.bk "$PWD" badpw
+}
+
+extract_backup() {
+    ./backup.sh -e "$PWD"/backup-*-*.tar.gz.enc badpw
+}
+
+test_backup() {
+    for dir in "$PWD/backup.sh.tmp/"backup-*-* ; do
+        if [ ! -d "$dir" ]; then
+            echo "Can't find '$dir' backup!"
+            exit 1
+        else
+            echo "Found '$dir'"
+        fi
+    done
+}
+
+
+if [ $# -eq 0 ]; then
+    helper
+    exit 1
+fi
+
+
+if [ "$1" = "I_HAVE_READ_THE_HELPER" ]; then
+    if [ "$(id -u)" -ne 0 ]; then
+        echo "Run this tool as root"
+        exit 1
+    fi
+
+    create_files
+    execute_backup
+    extract_backup
+    test_backup
+fi