diff --git a/10/backup.py b/10/backup.py
index c4bf67c..f34014c 100644
--- a/10/backup.py
+++ b/10/backup.py
@@ -9,11 +9,13 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS") or "STANDARD_IA"
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+AWS_ACCESS_KEY_ID = os.environ.get("AWS_ACCESS_KEY_ID")
+AWS_SECRET_ACCESS_KEY = os.environ.get("AWS_SECRET_ACCESS_KEY")
+S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS", "STANDARD_IA")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -23,17 +25,17 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 MAIL_TO = os.environ.get("MAIL_TO")
 MAIL_FROM = os.environ.get("MAIL_FROM")
 WEBHOOK = os.environ.get("WEBHOOK")
 WEBHOOK_METHOD = os.environ.get("WEBHOOK_METHOD")
 WEBHOOK_DATA = os.environ.get("WEBHOOK_DATA")
-WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS") or ""
+WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS", "")
 KEEP_BACKUP_DAYS = int(os.environ.get("KEEP_BACKUP_DAYS", 7))
 FILENAME = os.environ.get("FILENAME", DB_NAME + "_%Y-%m-%d")
-PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS") or ""
+PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS", "")
 
 file_name = dt.strftime(FILENAME)
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -112,8 +114,12 @@ def main():
     take_backup()
     backup_size=os.path.getsize(backup_file)
 
-    log("Uploading to S3")
-    upload_backup()
+    if AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY:
+        log("Uploading to S3")
+        upload_backup()
+    else:
+        log("Skipping S3 upload, no AWS credentials provided")
+
     log("Pruning local backup copies")
     prune_local_backup_files()
     end_time = datetime.now()
diff --git a/10/restore.py b/10/restore.py
index 4ce1d26..4abc06d 100644
--- a/10/restore.py
+++ b/10/restore.py
@@ -7,10 +7,10 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -20,7 +20,7 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 file_name = sys.argv[1]
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -48,7 +48,7 @@ def restore_backup():
     if not backup_exists():
         sys.stderr.write("Backup file doesn't exists!\n")
         sys.exit(1)
-    
+
     # restore postgres-backup
     env = os.environ.copy()
     if DB_USE_ENV:
@@ -71,10 +71,10 @@ def main():
     else:
         log("Downloading database dump")
         download_backup()
-    
+
     log("Restoring database")
     restore_backup()
-    
+
     log("Restore complete, took %.2f seconds" % (datetime.now() - start_time).total_seconds())
 
 if __name__ == "__main__":
diff --git a/11/backup.py b/11/backup.py
index c4bf67c..f34014c 100644
--- a/11/backup.py
+++ b/11/backup.py
@@ -9,11 +9,13 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS") or "STANDARD_IA"
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+AWS_ACCESS_KEY_ID = os.environ.get("AWS_ACCESS_KEY_ID")
+AWS_SECRET_ACCESS_KEY = os.environ.get("AWS_SECRET_ACCESS_KEY")
+S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS", "STANDARD_IA")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -23,17 +25,17 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 MAIL_TO = os.environ.get("MAIL_TO")
 MAIL_FROM = os.environ.get("MAIL_FROM")
 WEBHOOK = os.environ.get("WEBHOOK")
 WEBHOOK_METHOD = os.environ.get("WEBHOOK_METHOD")
 WEBHOOK_DATA = os.environ.get("WEBHOOK_DATA")
-WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS") or ""
+WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS", "")
 KEEP_BACKUP_DAYS = int(os.environ.get("KEEP_BACKUP_DAYS", 7))
 FILENAME = os.environ.get("FILENAME", DB_NAME + "_%Y-%m-%d")
-PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS") or ""
+PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS", "")
 
 file_name = dt.strftime(FILENAME)
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -112,8 +114,12 @@ def main():
     take_backup()
     backup_size=os.path.getsize(backup_file)
 
-    log("Uploading to S3")
-    upload_backup()
+    if AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY:
+        log("Uploading to S3")
+        upload_backup()
+    else:
+        log("Skipping S3 upload, no AWS credentials provided")
+
     log("Pruning local backup copies")
     prune_local_backup_files()
     end_time = datetime.now()
diff --git a/11/restore.py b/11/restore.py
index 4ce1d26..4abc06d 100644
--- a/11/restore.py
+++ b/11/restore.py
@@ -7,10 +7,10 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -20,7 +20,7 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 file_name = sys.argv[1]
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -48,7 +48,7 @@ def restore_backup():
     if not backup_exists():
         sys.stderr.write("Backup file doesn't exists!\n")
         sys.exit(1)
-    
+
     # restore postgres-backup
     env = os.environ.copy()
     if DB_USE_ENV:
@@ -71,10 +71,10 @@ def main():
     else:
         log("Downloading database dump")
         download_backup()
-    
+
     log("Restoring database")
     restore_backup()
-    
+
     log("Restore complete, took %.2f seconds" % (datetime.now() - start_time).total_seconds())
 
 if __name__ == "__main__":
diff --git a/12/backup.py b/12/backup.py
index c4bf67c..f34014c 100644
--- a/12/backup.py
+++ b/12/backup.py
@@ -9,11 +9,13 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS") or "STANDARD_IA"
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+AWS_ACCESS_KEY_ID = os.environ.get("AWS_ACCESS_KEY_ID")
+AWS_SECRET_ACCESS_KEY = os.environ.get("AWS_SECRET_ACCESS_KEY")
+S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS", "STANDARD_IA")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -23,17 +25,17 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 MAIL_TO = os.environ.get("MAIL_TO")
 MAIL_FROM = os.environ.get("MAIL_FROM")
 WEBHOOK = os.environ.get("WEBHOOK")
 WEBHOOK_METHOD = os.environ.get("WEBHOOK_METHOD")
 WEBHOOK_DATA = os.environ.get("WEBHOOK_DATA")
-WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS") or ""
+WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS", "")
 KEEP_BACKUP_DAYS = int(os.environ.get("KEEP_BACKUP_DAYS", 7))
 FILENAME = os.environ.get("FILENAME", DB_NAME + "_%Y-%m-%d")
-PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS") or ""
+PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS", "")
 
 file_name = dt.strftime(FILENAME)
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -112,8 +114,12 @@ def main():
     take_backup()
     backup_size=os.path.getsize(backup_file)
 
-    log("Uploading to S3")
-    upload_backup()
+    if AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY:
+        log("Uploading to S3")
+        upload_backup()
+    else:
+        log("Skipping S3 upload, no AWS credentials provided")
+
     log("Pruning local backup copies")
     prune_local_backup_files()
     end_time = datetime.now()
diff --git a/12/restore.py b/12/restore.py
index 4ce1d26..4abc06d 100644
--- a/12/restore.py
+++ b/12/restore.py
@@ -7,10 +7,10 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -20,7 +20,7 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 file_name = sys.argv[1]
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -48,7 +48,7 @@ def restore_backup():
     if not backup_exists():
         sys.stderr.write("Backup file doesn't exists!\n")
         sys.exit(1)
-    
+
     # restore postgres-backup
     env = os.environ.copy()
     if DB_USE_ENV:
@@ -71,10 +71,10 @@ def main():
     else:
         log("Downloading database dump")
         download_backup()
-    
+
     log("Restoring database")
     restore_backup()
-    
+
     log("Restore complete, took %.2f seconds" % (datetime.now() - start_time).total_seconds())
 
 if __name__ == "__main__":
diff --git a/13/backup.py b/13/backup.py
index c4bf67c..f34014c 100644
--- a/13/backup.py
+++ b/13/backup.py
@@ -9,11 +9,13 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS") or "STANDARD_IA"
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+AWS_ACCESS_KEY_ID = os.environ.get("AWS_ACCESS_KEY_ID")
+AWS_SECRET_ACCESS_KEY = os.environ.get("AWS_SECRET_ACCESS_KEY")
+S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS", "STANDARD_IA")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -23,17 +25,17 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 MAIL_TO = os.environ.get("MAIL_TO")
 MAIL_FROM = os.environ.get("MAIL_FROM")
 WEBHOOK = os.environ.get("WEBHOOK")
 WEBHOOK_METHOD = os.environ.get("WEBHOOK_METHOD")
 WEBHOOK_DATA = os.environ.get("WEBHOOK_DATA")
-WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS") or ""
+WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS", "")
 KEEP_BACKUP_DAYS = int(os.environ.get("KEEP_BACKUP_DAYS", 7))
 FILENAME = os.environ.get("FILENAME", DB_NAME + "_%Y-%m-%d")
-PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS") or ""
+PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS", "")
 
 file_name = dt.strftime(FILENAME)
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -112,8 +114,12 @@ def main():
     take_backup()
     backup_size=os.path.getsize(backup_file)
 
-    log("Uploading to S3")
-    upload_backup()
+    if AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY:
+        log("Uploading to S3")
+        upload_backup()
+    else:
+        log("Skipping S3 upload, no AWS credentials provided")
+
     log("Pruning local backup copies")
     prune_local_backup_files()
     end_time = datetime.now()
diff --git a/13/restore.py b/13/restore.py
index 4ce1d26..4abc06d 100644
--- a/13/restore.py
+++ b/13/restore.py
@@ -7,10 +7,10 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -20,7 +20,7 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 file_name = sys.argv[1]
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -48,7 +48,7 @@ def restore_backup():
     if not backup_exists():
         sys.stderr.write("Backup file doesn't exists!\n")
         sys.exit(1)
-    
+
     # restore postgres-backup
     env = os.environ.copy()
     if DB_USE_ENV:
@@ -71,10 +71,10 @@ def main():
     else:
         log("Downloading database dump")
         download_backup()
-    
+
     log("Restoring database")
     restore_backup()
-    
+
     log("Restore complete, took %.2f seconds" % (datetime.now() - start_time).total_seconds())
 
 if __name__ == "__main__":
diff --git a/14/backup.py b/14/backup.py
index c4bf67c..f34014c 100644
--- a/14/backup.py
+++ b/14/backup.py
@@ -9,11 +9,13 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS") or "STANDARD_IA"
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+AWS_ACCESS_KEY_ID = os.environ.get("AWS_ACCESS_KEY_ID")
+AWS_SECRET_ACCESS_KEY = os.environ.get("AWS_SECRET_ACCESS_KEY")
+S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS", "STANDARD_IA")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -23,17 +25,17 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 MAIL_TO = os.environ.get("MAIL_TO")
 MAIL_FROM = os.environ.get("MAIL_FROM")
 WEBHOOK = os.environ.get("WEBHOOK")
 WEBHOOK_METHOD = os.environ.get("WEBHOOK_METHOD")
 WEBHOOK_DATA = os.environ.get("WEBHOOK_DATA")
-WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS") or ""
+WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS", "")
 KEEP_BACKUP_DAYS = int(os.environ.get("KEEP_BACKUP_DAYS", 7))
 FILENAME = os.environ.get("FILENAME", DB_NAME + "_%Y-%m-%d")
-PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS") or ""
+PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS", "")
 
 file_name = dt.strftime(FILENAME)
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -112,8 +114,12 @@ def main():
     take_backup()
     backup_size=os.path.getsize(backup_file)
 
-    log("Uploading to S3")
-    upload_backup()
+    if AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY:
+        log("Uploading to S3")
+        upload_backup()
+    else:
+        log("Skipping S3 upload, no AWS credentials provided")
+
     log("Pruning local backup copies")
     prune_local_backup_files()
     end_time = datetime.now()
diff --git a/14/restore.py b/14/restore.py
index 4ce1d26..4abc06d 100644
--- a/14/restore.py
+++ b/14/restore.py
@@ -7,10 +7,10 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -20,7 +20,7 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 file_name = sys.argv[1]
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -48,7 +48,7 @@ def restore_backup():
     if not backup_exists():
         sys.stderr.write("Backup file doesn't exists!\n")
         sys.exit(1)
-    
+
     # restore postgres-backup
     env = os.environ.copy()
     if DB_USE_ENV:
@@ -71,10 +71,10 @@ def main():
     else:
         log("Downloading database dump")
         download_backup()
-    
+
     log("Restoring database")
     restore_backup()
-    
+
     log("Restore complete, took %.2f seconds" % (datetime.now() - start_time).total_seconds())
 
 if __name__ == "__main__":
diff --git a/15/backup.py b/15/backup.py
index c4bf67c..f34014c 100644
--- a/15/backup.py
+++ b/15/backup.py
@@ -9,11 +9,13 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS") or "STANDARD_IA"
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+AWS_ACCESS_KEY_ID = os.environ.get("AWS_ACCESS_KEY_ID")
+AWS_SECRET_ACCESS_KEY = os.environ.get("AWS_SECRET_ACCESS_KEY")
+S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS", "STANDARD_IA")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -23,17 +25,17 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 MAIL_TO = os.environ.get("MAIL_TO")
 MAIL_FROM = os.environ.get("MAIL_FROM")
 WEBHOOK = os.environ.get("WEBHOOK")
 WEBHOOK_METHOD = os.environ.get("WEBHOOK_METHOD")
 WEBHOOK_DATA = os.environ.get("WEBHOOK_DATA")
-WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS") or ""
+WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS", "")
 KEEP_BACKUP_DAYS = int(os.environ.get("KEEP_BACKUP_DAYS", 7))
 FILENAME = os.environ.get("FILENAME", DB_NAME + "_%Y-%m-%d")
-PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS") or ""
+PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS", "")
 
 file_name = dt.strftime(FILENAME)
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -112,8 +114,12 @@ def main():
     take_backup()
     backup_size=os.path.getsize(backup_file)
 
-    log("Uploading to S3")
-    upload_backup()
+    if AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY:
+        log("Uploading to S3")
+        upload_backup()
+    else:
+        log("Skipping S3 upload, no AWS credentials provided")
+
     log("Pruning local backup copies")
     prune_local_backup_files()
     end_time = datetime.now()
diff --git a/15/restore.py b/15/restore.py
index 4ce1d26..4abc06d 100644
--- a/15/restore.py
+++ b/15/restore.py
@@ -7,10 +7,10 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -20,7 +20,7 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 file_name = sys.argv[1]
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -48,7 +48,7 @@ def restore_backup():
     if not backup_exists():
         sys.stderr.write("Backup file doesn't exists!\n")
         sys.exit(1)
-    
+
     # restore postgres-backup
     env = os.environ.copy()
     if DB_USE_ENV:
@@ -71,10 +71,10 @@ def main():
     else:
         log("Downloading database dump")
         download_backup()
-    
+
     log("Restoring database")
     restore_backup()
-    
+
     log("Restore complete, took %.2f seconds" % (datetime.now() - start_time).total_seconds())
 
 if __name__ == "__main__":
diff --git a/16/backup.py b/16/backup.py
index c4bf67c..f34014c 100644
--- a/16/backup.py
+++ b/16/backup.py
@@ -9,11 +9,13 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS") or "STANDARD_IA"
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+AWS_ACCESS_KEY_ID = os.environ.get("AWS_ACCESS_KEY_ID")
+AWS_SECRET_ACCESS_KEY = os.environ.get("AWS_SECRET_ACCESS_KEY")
+S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS", "STANDARD_IA")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -23,17 +25,17 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 MAIL_TO = os.environ.get("MAIL_TO")
 MAIL_FROM = os.environ.get("MAIL_FROM")
 WEBHOOK = os.environ.get("WEBHOOK")
 WEBHOOK_METHOD = os.environ.get("WEBHOOK_METHOD")
 WEBHOOK_DATA = os.environ.get("WEBHOOK_DATA")
-WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS") or ""
+WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS", "")
 KEEP_BACKUP_DAYS = int(os.environ.get("KEEP_BACKUP_DAYS", 7))
 FILENAME = os.environ.get("FILENAME", DB_NAME + "_%Y-%m-%d")
-PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS") or ""
+PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS", "")
 
 file_name = dt.strftime(FILENAME)
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -112,8 +114,12 @@ def main():
     take_backup()
     backup_size=os.path.getsize(backup_file)
 
-    log("Uploading to S3")
-    upload_backup()
+    if AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY:
+        log("Uploading to S3")
+        upload_backup()
+    else:
+        log("Skipping S3 upload, no AWS credentials provided")
+
     log("Pruning local backup copies")
     prune_local_backup_files()
     end_time = datetime.now()
diff --git a/16/restore.py b/16/restore.py
index 4ce1d26..4abc06d 100644
--- a/16/restore.py
+++ b/16/restore.py
@@ -7,10 +7,10 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -20,7 +20,7 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 file_name = sys.argv[1]
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -48,7 +48,7 @@ def restore_backup():
     if not backup_exists():
         sys.stderr.write("Backup file doesn't exists!\n")
         sys.exit(1)
-    
+
     # restore postgres-backup
     env = os.environ.copy()
     if DB_USE_ENV:
@@ -71,10 +71,10 @@ def main():
     else:
         log("Downloading database dump")
         download_backup()
-    
+
     log("Restoring database")
     restore_backup()
-    
+
     log("Restore complete, took %.2f seconds" % (datetime.now() - start_time).total_seconds())
 
 if __name__ == "__main__":
diff --git a/README.md b/README.md
index 059aaa6..e935f06 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 [![Build Status](https://github.com/heyman/postgresql-backup/workflows/Test/badge.svg)](https://github.com/heyman/postgresql-backup/actions?query=workflow%3ATest)
 
-Docker image that periodically dumps a Postgres database, and uploads it to an Amazon S3 bucket.
+Docker image that periodically dumps a Postgres database, and optionally uploads it to an Amazon S3 bucket.
 
 Available on Docker Hub: [heyman/postgresql-backup](https://hub.docker.com/r/heyman/postgresql-backup)
 
@@ -28,13 +28,13 @@ docker run -it --rm --name=pgbackup \
 * `DB_PASS`: Postgres password
 * `DB_USER`: Postgres username
 * `DB_NAME`: Name of database
+
+## Optional environment variables
+
 * `S3_PATH`: Amazon S3 path in the format: s3://bucket-name/some/path
 * `AWS_ACCESS_KEY_ID`
 * `AWS_SECRET_ACCESS_KEY`
 * `AWS_DEFAULT_REGION`
-
-## Optional environment variables
-
 * `S3_STORAGE_CLASS`: Specify [storage class](https://docs.aws.amazon.com/AmazonS3/latest/userguide/storage-class-intro.html) for the uploaded object, defaults to `STANDARD_IA`.
 * `S3_EXTRA_OPTIONS`: Specify additional options for S3, e.g. `--endpoint=` for using custom S3 provider.
 * `DB_USE_ENV`: Inject [postgres environment variables](https://www.postgresql.org/docs/13/libpq-envars.html) from the environment. Ignores `DB_HOST`, `DB_PASS`, `DB_USER` and `DB_NAME`. Can be used to specify advanced connections, e.g. using mTLS connection.
@@ -71,7 +71,7 @@ Text in `WEBHOOK_DATA` is interpolated with variabels `%(my_var)s`
 
 #### Example on how to post a Slack message when a backup is complete
 
-1. Configure a webhook as described in the Slack [documentation](https://api.slack.com/messaging/webhooks). 
+1. Configure a webhook as described in the Slack [documentation](https://api.slack.com/messaging/webhooks).
 2. Set `WEBHOOK` and `WEBHOOK_` accodringly:
    ```
    WEBHOOK=https://hooks.slack.com/services/.../.../...
@@ -82,13 +82,13 @@ Text in `WEBHOOK_DATA` is interpolated with variabels `%(my_var)s`
 
 ## Volumes
 
-* `/data/backups` - The database is dumped in into this directory
+* `/data/backups` - The database is dumped into this directory
 
 ## Restoring a backup
 
-This image can also be run as a one off task to restore one of the backups. 
-To do this, we run the container with the command: `python -u /backup/restore.py [S3-filename]` 
-(`S3-filename` should only be the name of the file, the directory is set through the `S3_PATH` env variable).
+This image can also be run as a one off task to restore one of the backups.
+To do this, we run the container with the command: `python -u /backup/restore.py [backup-filename]`
+(`backup-filename` should only be the name of the file, the directory is set through the `S3_PATH` env variable, if it needs to be downloaded).
 
 The following environment variables are required:
 
@@ -96,6 +96,9 @@ The following environment variables are required:
 * `DB_PASS`: Postgres password
 * `DB_USER`: Postgres username
 * `DB_NAME`: Name of database to import into
+
+The following environment variables are required if the file to restore is not already in the backup volume:
+
 * `S3_PATH`: Amazon S3 directory path in the format: s3://bucket-name/some/path
 * `AWS_ACCESS_KEY_ID`
 * `AWS_SECRET_ACCESS_KEY`
@@ -108,17 +111,16 @@ The following environment variables are required:
 
 ## Taking a one off backup
 
-To run a one off backup job, e.g. to test that it works when setting it up for the first time, simply start 
-the container with the docker run command set to `python -u /backup/backup.py` (as well as all the required environment 
+To run a one off backup job, e.g. to test that it works when setting it up for the first time, simply start
+the container with the docker run command set to `python -u /backup/backup.py` (as well as all the required environment
 variables set).
 
-
 ## Docker tags
 
-This image uses the alpine version(s) of the [official postgres](https://hub.docker.com/_/postgres) image as base 
+This image uses the alpine version(s) of the [official postgres](https://hub.docker.com/_/postgres) image as base
 image.
 
-The following docker tags are available for this image, and they are based on the corresponding official postgres 
+The following docker tags are available for this image, and they are based on the corresponding official postgres
 alpine image:
 
 * `16`, `latest`
@@ -128,4 +130,3 @@ alpine image:
 * `12`
 * `11`
 * `10`
-
diff --git a/template/backup.py b/template/backup.py
index c4bf67c..f34014c 100644
--- a/template/backup.py
+++ b/template/backup.py
@@ -9,11 +9,13 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS") or "STANDARD_IA"
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+AWS_ACCESS_KEY_ID = os.environ.get("AWS_ACCESS_KEY_ID")
+AWS_SECRET_ACCESS_KEY = os.environ.get("AWS_SECRET_ACCESS_KEY")
+S3_STORAGE_CLASS = os.environ.get("S3_STORAGE_CLASS", "STANDARD_IA")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -23,17 +25,17 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 MAIL_TO = os.environ.get("MAIL_TO")
 MAIL_FROM = os.environ.get("MAIL_FROM")
 WEBHOOK = os.environ.get("WEBHOOK")
 WEBHOOK_METHOD = os.environ.get("WEBHOOK_METHOD")
 WEBHOOK_DATA = os.environ.get("WEBHOOK_DATA")
-WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS") or ""
+WEBHOOK_CURL_OPTIONS = os.environ.get("WEBHOOK_CURL_OPTIONS", "")
 KEEP_BACKUP_DAYS = int(os.environ.get("KEEP_BACKUP_DAYS", 7))
 FILENAME = os.environ.get("FILENAME", DB_NAME + "_%Y-%m-%d")
-PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS") or ""
+PG_DUMP_EXTRA_OPTIONS = os.environ.get("PG_DUMP_EXTRA_OPTIONS", "")
 
 file_name = dt.strftime(FILENAME)
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -112,8 +114,12 @@ def main():
     take_backup()
     backup_size=os.path.getsize(backup_file)
 
-    log("Uploading to S3")
-    upload_backup()
+    if AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY:
+        log("Uploading to S3")
+        upload_backup()
+    else:
+        log("Skipping S3 upload, no AWS credentials provided")
+
     log("Pruning local backup copies")
     prune_local_backup_files()
     end_time = datetime.now()
diff --git a/template/restore.py b/template/restore.py
index 4ce1d26..4abc06d 100644
--- a/template/restore.py
+++ b/template/restore.py
@@ -7,10 +7,10 @@
 
 BACKUP_DIR = os.environ["BACKUP_DIR"]
 
-S3_PATH = os.environ["S3_PATH"]
-S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS") or ""
+S3_PATH = os.environ.get("S3_PATH", "")
+S3_EXTRA_OPTIONS = os.environ.get("S3_EXTRA_OPTIONS", "")
 
-DB_USE_ENV = os.environ.get("DB_USE_ENV") or False
+DB_USE_ENV = os.environ.get("DB_USE_ENV", False)
 DB_NAME = os.environ["DB_NAME"] if "DB_NAME" in os.environ else os.environ.get("PGDATABASE")
 
 if not DB_NAME:
@@ -20,7 +20,7 @@
     DB_HOST = os.environ["DB_HOST"]
     DB_PASS = os.environ["DB_PASS"]
     DB_USER = os.environ["DB_USER"]
-    DB_PORT = os.environ.get("DB_PORT") or "5432"
+    DB_PORT = os.environ.get("DB_PORT", "5432")
 
 file_name = sys.argv[1]
 backup_file = os.path.join(BACKUP_DIR, file_name)
@@ -48,7 +48,7 @@ def restore_backup():
     if not backup_exists():
         sys.stderr.write("Backup file doesn't exists!\n")
         sys.exit(1)
-    
+
     # restore postgres-backup
     env = os.environ.copy()
     if DB_USE_ENV:
@@ -71,10 +71,10 @@ def main():
     else:
         log("Downloading database dump")
         download_backup()
-    
+
     log("Restoring database")
     restore_backup()
-    
+
     log("Restore complete, took %.2f seconds" % (datetime.now() - start_time).total_seconds())
 
 if __name__ == "__main__":