add side container which backups tt-rss database once a week

bump alpine image to 3.12

README.md

@@ -15,6 +15,7 @@ General outline of the configuration is as follows:
  - Caddy has its http port exposed to the outside
  - optional SSL support via Caddy w/ automatic letsencrypt certificates
  - feed updates are handled via update daemon started in a separate container (updater)
+ - optional backups container which performs tt-rss database backup once a week
 
 ### Installation
 

app/Dockerfile

@@ -1,7 +1,7 @@
-FROM alpine:3.9
+FROM alpine:3.12
 EXPOSE 9000/tcp
 
-RUN apk add --no-cache php7 php7-fpm \
+RUN apk add --no-cache dcron php7 php7-fpm \
 	php7-pdo php7-gd php7-pgsql php7-pdo_pgsql php7-mbstring \
 	php7-intl php7-xml php7-curl php7-session \
 	php7-dom php7-fileinfo php7-json \
@@ -11,6 +11,8 @@ RUN apk add --no-cache php7 php7-fpm \
 ADD startup.sh /
 ADD updater.sh /
 ADD index.php /
+ADD dcron.sh /
+ADD backup-database.sh /etc/periodic/weekly/backup-database
 
 RUN sed -i.bak 's/^listen = 127.0.0.1:9000/listen = 9000/' /etc/php7/php-fpm.d/www.conf
 RUN sed -i.bak 's/\(memory_limit =\) 128M/\1 256M/' /etc/php7/php.ini

app/backup-database.sh

@@ -0,0 +1,22 @@
+#!/bin/sh -e
+
+DST_DIR=/backups
+KEEP_DAYS=28
+
+if pg_isready -h $DB_HOST -U $DB_USER; then
+	DST_FILE=ttrss-backup-$(date +%Y%m%d).sql.gz
+
+	echo backing up tt-rss database to $DST_DIR/$DST_FILE...
+
+	export PGPASSWORD=$DB_PASS 
+
+	pg_dump --clean -h $DB_HOST -U $DB_USER $DB_NAME | gzip > $DST_DIR/$DST_FILE
+
+	echo cleaning up...
+
+	find $DST_DIR -type f -name '*.sql.gz' -mtime +$KEEP_DAYS -delete
+
+	echo done.
+else
+	echo backup failed: database is not ready.
+fi

app/dcron.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+# https://github.com/dubiousjim/dcron/issues/13
+set -e
+
+/usr/sbin/crond "$@"

docker-compose.yml

@@ -32,6 +32,25 @@ services:
     depends_on:
       - db
 
+  backups:
+    build:
+      context:
+        ./app
+    restart: unless-stopped
+    environment:
+      - DB_TYPE=pgsql
+      - DB_HOST=db
+      - DB_NAME=${POSTGRES_USER}
+      - DB_USER=${POSTGRES_USER}
+      - DB_PASS=${POSTGRES_PASSWORD}
+      - OWNER_UID=${OWNER_UID}
+      - OWNER_GID=${OWNER_GID}
+    volumes:
+      - backups:/backups
+    depends_on:
+      - db
+    command: /dcron.sh -f
+
   updater:
     build:
       context:
@@ -91,3 +110,4 @@ volumes:
   db:
   app:  
   certs:
+  backups: