Allow overriding cron schedule, fix vars

.env.sample

@@ -4,10 +4,16 @@ SECRET_RESTIC_PASSWORD_VERSION=v1
 
 COMPOSE_FILE=compose.yml
 
+SERVER_NAME=example.com
+RESTIC_HOST=minio.example.com
+
+CRON_SCHEDULE='*/5 * * * *'
+
 # SSH storage
 #SECRET_SSH_KEY_VERSION=v1
 #COMPOSE_FILE="$COMPOSE_FILE:compose.ssh.yml"
 
 # S3 storage
 #SECRET_AWS_SECRET_ACCESS_KEY_VERSION=v1
+#AWS_ACCESS_KEY_ID=something-secret
 #COMPOSE_FILE="$COMPOSE_FILE:compose.s3.yml"

Dockerfile

@@ -7,9 +7,7 @@ RUN apk add --upgrade --no-cache \
   restic
 
 COPY backup.sh /usr/bin/backup.sh
-RUN chmod +x /usr/bin/backup.sh
+COPY setup-cron.sh /usr/bin/setup-cron.sh
+RUN chmod +x /usr/bin/backup.sh /usr/bin/setup-cron.sh
 
-RUN echo "*       *       *       *       *       /usr/bin/backup.sh" | crontab -
-RUN crontab -l
-
-ENTRYPOINT ["crond", "-f", "-L", "/dev/stdout"]
+ENTRYPOINT [ "/usr/bin/setup-cron.sh" ]

compose.yml

@@ -8,6 +8,7 @@ services:
       - "/var/run/docker.sock:/var/run/docker.sock"
       - "backups:/backups"
     environment:
+      - CRON_SCHEDULE
       - RESTIC_REPO
       - RESTIC_PASSWORD_FILE=/run/secrets/restic_password
       - BACKUP_DEST=/backups

setup-cron.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+set -e
+set -o pipefail
+
+cron_schedule="${CRON_SCHEDULE:?CRON_SCHEDULE not set}"
+
+echo "$cron_schedule /usr/bin/backup.sh" | crontab -
+crontab -l
+
+crond -f -L /dev/stdout