Allow to not validate on start

Closes #165

README.md

@@ -82,6 +82,7 @@ Most variables are the same as in the [official postgres image](https://hub.dock
 | BACKUP_KEEP_MONTHS | Number of monthly backups to keep before removal. Defaults to `6`. |
 | BACKUP_KEEP_MINS | Number of minutes for `last` folder backups to keep before removal. Defaults to `1440`. |
 | BACKUP_LATEST_TYPE | Type of `latest` pointer (`symlink`,`hardlink`,`none`). Defaults to `symlink`. |
+| VALIDATE_ON_START | If set to `FALSE` does not validate the configuration on start. Disabling this is not recommended. Defaults to `TRUE`. |
 | HEALTHCHECK_PORT | Port listening for cron-schedule health check. Defaults to `8080`. |
 | POSTGRES_DB | Comma or space separated list of postgres databases to backup. If POSTGRES_CLUSTER is set this refers to the database to connect to for dumping global objects and discovering what other databases should be dumped (typically is either `postgres` or `template1`). Required. |
 | POSTGRES_DB_FILE | Alternative to POSTGRES_DB, but with one database per line, for usage with docker secrets. |

alpine.Dockerfile

@@ -21,6 +21,7 @@ ENV POSTGRES_DB="**None**" \
     POSTGRES_EXTRA_OPTS="-Z1" \
     POSTGRES_CLUSTER="FALSE" \
     SCHEDULE="@daily" \
+    VALIDATE_ON_START="TRUE" \
     BACKUP_ON_START="FALSE" \
     BACKUP_DIR="/backups" \
     BACKUP_SUFFIX=".sql.gz" \

debian.Dockerfile

@@ -35,6 +35,7 @@ ENV POSTGRES_DB="**None**" \
     POSTGRES_EXTRA_OPTS="-Z1" \
     POSTGRES_CLUSTER="FALSE" \
     SCHEDULE="@daily" \
+    VALIDATE_ON_START="TRUE" \
     BACKUP_ON_START="FALSE" \
     BACKUP_DIR="/backups" \
     BACKUP_SUFFIX=".sql.gz" \

init.sh

@@ -2,7 +2,9 @@
 set -Eeo pipefail
 
 # Prevalidate configuration (don't source)
-/env.sh
+if [ "${VALIDATE_ON_START}" = "TRUE" ]; then
+  /env.sh
+fi
 
 EXTRA_ARGS=""
 # Initial background backup