Allow set but empty envvars

CHANGELOG.md

@@ -6,11 +6,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [3.0.1] - 2022-02-01
+### Fixed
+- Environment variable assertion should allow empty values e.g. `RESTIC_BACKUP_EXTRA_ARGS`
+
 ## [3.0.0] - 2022-02-01
 ### Added
 - Allow extra arguments to restic-backup with `$RESTIC_BACKUP_EXTRA_ARGS`.
 - Add `$RESTIC_VERBOSITY_LEVEL` for debugging.
-- Assertion on all needed envionment variables in the backup and check scripts.
+- Assertion on all needed environment variables in the backup and check scripts.
 - Added linter (`shellcheck(1)`) that is run on push and PRs.
 
 ### Changed

usr/local/sbin/restic_backup.sh

@@ -16,9 +16,8 @@ set -euo pipefail
 assert_envvars() {
 	local varnames=("$@")
 	for varname in "${varnames[@]}"; do
-		# Check if variable is set, then if it is not empty (need to do both as of `set -u`).
-		if [ -z ${!varname+x} ] || [ -z "${!varname}" ] ; then
-			printf "%s must be set with a value for this script to work.\n\nDid you forget to source a /etc/restic/*.env profile in the current shell before executing this script?\n" "$varname" >&2
+		if [ -z ${!varname+x} ]; then
+			printf "%s must be set for this script to work.\n\nDid you forget to source a /etc/restic/*.env profile in the current shell before executing this script?\n" "$varname" >&2
 			exit 1
 		fi
 	done

usr/local/sbin/restic_check.sh

@@ -9,9 +9,8 @@ set -euo pipefail
 assert_envvars() {
 	local varnames=("$@")
 	for varname in "${varnames[@]}"; do
-		# Check if variable is set, then if it is not empty (need to do both as of `set -u`).
-		if [ -z ${!varname+x} ] || [ -z "${!varname}" ] ; then
-			printf "%s must be set with a value for this script to work.\n\nDid you forget to source a /etc/restic/*.env profile in the current shell before executing this script?\n" "$varname" >&2
+		if [ -z ${!varname+x} ]; then
+			printf "%s must be set for this script to work.\n\nDid you forget to source a /etc/restic/*.env profile in the current shell before executing this script?\n" "$varname" >&2
 			exit 1
 		fi
 	done