Make one env optional and warn about optional missing envs (#110)

* Make one env optional and warn about optional missing envs

* Restrict visibility of var

* Fix warning

* Dont print empty warning list

bin/restic_backup.sh

@@ -33,17 +33,38 @@ assert_envvars() {
 		fi
 	done
 }
+
+warn_on_missing_envvars() {
+	local unset_envs=()
+	local varnames=("$@")
+	for varname in "${varnames[@]}"; do
+		if [ -z "${!varname}" ]; then
+			unset_envs=("${unset_envs[@]}" "$varname")
+		fi
+	done
+	
+	if [ ${#unset_envs[@]} -gt 0 ]; then
+		printf "The following env variables are recommended, but have not been set. This script may not work as expected: %s\n" "${unset_envs[*]}" >&2
+	fi
+}
+
 assert_envvars \
-	B2_ACCOUNT_ID B2_ACCOUNT_KEY B2_CONNECTIONS \
 	RESTIC_BACKUP_PATHS RESTIC_BACKUP_TAG \
-	RESTIC_BACKUP_EXCLUDE_FILE RESTIC_BACKUP_EXTRA_ARGS RESTIC_PASSWORD_FILE RESTIC_REPOSITORY RESTIC_VERBOSITY_LEVEL \
+	RESTIC_BACKUP_EXCLUDE_FILE RESTIC_BACKUP_EXTRA_ARGS RESTIC_REPOSITORY RESTIC_VERBOSITY_LEVEL \
 	RESTIC_RETENTION_DAYS RESTIC_RETENTION_MONTHS RESTIC_RETENTION_WEEKS RESTIC_RETENTION_YEARS
 
+warn_on_missing_envvars \
+	B2_ACCOUNT_ID B2_ACCOUNT_KEY B2_CONNECTIONS \
+	RESTIC_PASSWORD_FILE
+
 
 # Convert to arrays, as arrays should be used to build command lines. See https://github.com/koalaman/shellcheck/wiki/SC2086
 IFS=':' read -ra backup_paths <<< "$RESTIC_BACKUP_PATHS"
 IFS=' ' read -ra extra_args <<< "$RESTIC_BACKUP_EXTRA_ARGS"
 
+B2_ARG=
+[ -z "${B2_CONNECTIONS+x}" ] || B2_ARG=(--option b2.connections="$B2_CONNECTIONS")
+
 # If you need to run some commands before performing the backup; create this file, put them there and make the file executable.
 PRE_SCRIPT="${INSTALL_PREFIX}/etc/restic/pre_backup.sh"
 test -x "$PRE_SCRIPT" && "$PRE_SCRIPT"
@@ -81,7 +102,7 @@ restic backup \
 	--verbose="$RESTIC_VERBOSITY_LEVEL" \
 	$FS_ARG \
 	--tag "$RESTIC_BACKUP_TAG" \
-	--option b2.connections="$B2_CONNECTIONS" \
+	"${B2_ARG[@]}" \
 	"${exclusion_args[@]}" \
 	"${extra_args[@]}" \
 	"${backup_paths[@]}" &
@@ -93,7 +114,7 @@ wait $!
 restic forget \
 	--verbose="$RESTIC_VERBOSITY_LEVEL" \
 	--tag "$RESTIC_BACKUP_TAG" \
-	--option b2.connections="$B2_CONNECTIONS" \
+	"${B2_ARG[@]}" \
 	--prune \
 	--group-by "paths,tags" \
 	--keep-hourly "$RESTIC_RETENTION_HOURS" \

bin/restic_check.sh

@@ -25,10 +25,29 @@ assert_envvars() {
 		fi
 	done
 }
-assert_envvars \
+
-	B2_ACCOUNT_ID B2_ACCOUNT_KEY B2_CONNECTIONS \
+warn_on_missing_envvars() {
+	local unset_envs=()
+	local varnames=("$@")
+	for varname in "${varnames[@]}"; do
+		if [ -z "${!varname}" ]; then
+			unset_envs=("${unset_envs[@]}" "$varname")
+		fi
+	done
+	
+	if [ ${#unset_envs[@]} -gt 0 ]; then
+		printf "The following env variables are recommended, but have not been set. This script may not work as expected: %s\n" "${unset_envs[*]}" >&2
+	fi
+}
+
+assert_envvars\
 	RESTIC_PASSWORD_FILE RESTIC_REPOSITORY RESTIC_VERBOSITY_LEVEL
 
+warn_on_missing_envvars \
+	B2_ACCOUNT_ID B2_ACCOUNT_KEY B2_CONNECTIONS
+
+B2_ARG=
+[ -z "${B2_CONNECTIONS+x}" ] || B2_ARG=(--option b2.connections="$B2_CONNECTIONS")
 
 # Remove locks from other stale processes to keep the automated backup running.
 # NOTE nope, don't unlock like restic_backup.sh. restic_backup.sh should take precedence over this script.
@@ -36,7 +55,7 @@ assert_envvars \
 #wait $!
 
 # Check repository for errors.
-restic check \
+echo restic check \
-	--option b2.connections="$B2_CONNECTIONS" \
+	"${B2_ARG[@]}" \
 	--verbose="$RESTIC_VERBOSITY_LEVEL" &
 wait $!