Added cron via env variables

README.md

@@ -329,6 +329,18 @@ To access the PostgreSQL logs you can use `docker exec`. For example:
 docker exec -it postgresql tail -f /var/log/postgresql/postgresql-9.4-main.log
 ```
 
+## Cron
+
+To schedule cron jobs in the container add variables named `POSTGRES_CRON_X` :
+
+```bash
+docker run --name postgresql -itd --restart always \
+  --publish 5432:5432 \
+  --volume /srv/docker/postgresql:/var/lib/postgresql \
+  --env "POSTGRES_CRON_1=* * * * * postgres date >> /tmp/crond.log 2>&1"
+  sameersbn/postgresql:9.5-2
+```
+
 # UID/GID mapping
 
 The files and processes created by the container are owned by the `postgres` user that is internal to the container. In the absense of user namespace in docker the UID and GID of the containers `postgres` user may have different meaning on the host.

entrypoint.sh

@@ -26,6 +26,8 @@ if [[ -z ${1} ]]; then
 
   configure_postgresql
 
+  create_crond
+
   echo "Starting PostgreSQL ${PG_VERSION}..."
   exec start-stop-daemon --start --chuid ${PG_USER}:${PG_USER} \
     --exec ${PG_BINDIR}/postgres -- -D ${PG_DATADIR} ${EXTRA_ARGS}

runtime/functions

@@ -12,6 +12,28 @@ exec_as_postgres() {
   sudo -HEu ${PG_USER} "$@"
 }
 
+create_crond() {
+# Provide POSTGRES_CRON_* via environment variable
+rm -rf /etc/cron.d/${PG_USER}
+for item in `env`; do
+   case "$item" in
+       POSTGRES_CRON*)
+            ENVVAR=`echo $item | cut -d \= -f 1`
+            printenv $ENVVAR >> /etc/cron.d/${PG_USER}
+            ;;
+   esac
+done
+
+if [ -f /etc/cron.d/${PG_USER} ]; then
+    sed -i "s/^session    required     pam_loginuid.so/#session    required     pam_loginuid.so/g" /etc/pam.d/cron
+    echo "Running cron(s)                                    "
+    echo "***************************************************"
+    cat /etc/cron.d/${PG_USER}
+    echo "***************************************************"
+    cron
+fi
+}
+
 map_uidgid() {
   USERMAP_ORIG_UID=$(id -u ${PG_USER})
   USERMAP_ORIG_GID=$(id -g ${PG_USER})