Merge branch 'fix-db-detection' into 'master'

Fix db detection

Also changes variables and drops the auto-detection

See merge request ix.ai/mariadb-backup!1

Author: tlex

Dockerfile

@@ -1,6 +1,6 @@
 FROM debian:buster
 LABEL MAINTAINER="docker@ix.ai"
-ENV DEBIAN_FRONTEND=noninteractive TERM=linux
+ENV DEBIAN_FRONTEND=noninteractive TERM=linux DB_PORT=3306 DB_USER=root
 
 RUN groupadd -g 666 mybackup && \
     useradd -u 666 -g 666 -d /backup -c "MariaDB Backup User" mybackup && \

README.md

@@ -8,12 +8,16 @@ The backup is made with [mydumper](http://centminmod.com/mydumper.html), a fast
 Usage
 =====
 
-To backup a [MySQL](https://hub.docker.com/_/mysql/) or [MariaDB](https://hub.docker.com/_/mariadb/) container you simply have to run a container from this Docker image and link a MySQL or MariaDB container to it.
+To backup a [MySQL](https://hub.docker.com/_/mysql/) or [MariaDB](https://hub.docker.com/_/mariadb/) database, you simply specify the credentials and the host. You can optionally specify the database as well.
 
-The container will automatically detect the linked database container and tries to backup the database based on the environment variables of the database container:
+Environment variables
+=====================
 
-* `<CONTAINER>_ENV_MYSQL_DATABASE`
-* `<CONTAINER>_ENV_MYSQL_ROOT_PASSWORD`
+* `DB_HOST` (mandatory, no default): The host to connect to
+* `DB_PASS` (mandatory, no default): The password to use
+* `DB_NAME` (optional, no default): If specified, only this database will be backed up
+* `DB_PORT` (optional, default `3306`): The password for the SQL server
+* `DB_USER` (optional, default `root`): The user to connect to the SQL server
 
 Please note the backup will be written to `/backup` by default, so you might want to mount that directory from your host.
 
@@ -23,7 +27,7 @@ Example Docker CLI client
 To __create a backup__ from a MySQL container via `docker` CLI client:
 
 ```bash
-docker run --name my-backup --link my-mysql -v /var/mysql_backups:/backup registry.gitlab.com/ix.ai/mariadb-backup
+docker run --name my-backup -e DB_HOST=mariadb -e DB_PASS=amazing_pass -v /var/mysql_backups:/backup registry.gitlab.com/ix.ai/mariadb-backup
 ```
 
 The container will stop automatically as soon as the backup has finished.
@@ -36,22 +40,7 @@ docker start my-backup
 To __restore a backup__ into a MySQL container via `docker` CLI client:
 
 ```bash
-docker run --name my-restore --link my-mysql -v /var/mysql_backups:/backup registry.gitlab.com/ix.ai/mariadb-backup
-```
-
-Example Docker Compose
-----------------------
-
-Here's an example of a [Docker Compose](https://docs.docker.com/compose/) file, e.g. `docker-compose.yml`:
-
-```yaml
-backup:
-    image: registry.gitlab.com/ix.ai/mariadb-backup
-    volumes:
-        - ./data/backup:/backup
-    links:
-        - my-mysql
-    restart: "no"
+docker run --name my-restore -e DB_HOST=mariadb -e DB_PASS=amazing_pass -v /var/mysql_backups:/backup registry.gitlab.com/ix.ai/mariadb-backup
 ```
 
 Configuration

init.sh

@@ -8,6 +8,8 @@ set -e
 
 MODE=${MODE:-BACKUP}
 TARBALL=${TARBALL:-}
+DB_PORT=${DB_PORT:-3306}
+DB_USER=${DB_USER:-root}
 
 case "${MODE^^}" in
     'BACKUP')
@@ -53,35 +55,33 @@ echo
 # Display the container informations on standard out.
 #
 
-CONTAINER=$(export | sed -nr "/ENV_MYSQL_ROOT_PASSWORD/{s/^.+ -x (.+)_ENV.+/\1/p;q}")
-
-if [[ -z "${CONTAINER}" ]]
+if [[ -z "${DB_HOST}" ]]
 then
-    echo "ERROR: Couldn't find linked MySQL container." >&2
+    echo "ERROR: Couldn't find the SQL host." >&2
     echo >&2
-    echo "Please link a MySQL or MariaDB container to the backup container and try again" >&2
+    echo "Please set the DB_HOST environment variable" >&2
     exit 1
 fi
 
-DB_PORT=$(export | sed -nr "/-x ${CONTAINER}_PORT_[[:digit:]]+_TCP_PORT/{s/^.+ -x (.+)=.+/\1/p}")
-DB_ADDR="${CONTAINER}_PORT_${!DB_PORT}_TCP_ADDR"
-DB_NAME="${CONTAINER}_ENV_MYSQL_DATABASE"
-DB_PASS="${CONTAINER}_ENV_MYSQL_ROOT_PASSWORD"
+if [[ -z "${DB_PASS}" ]]
+then
+    echo "ERROR: Couldn't find the password for the root user." >&2
+    echo >&2
+    echo "Please set the DB_PASS environment variable" >&2
+    exit 1
+fi
 
-echo "CONTAINER SETTINGS"
-echo "=================="
+echo "DATABASE SETTINGS"
+echo "================="
 echo
-echo "  Container: ${CONTAINER}"
-echo
-echo "  Address:   ${!DB_ADDR}"
-echo "  Port:      ${!DB_PORT}"
-echo
-
-if [[ -n "${!DB_NAME}" ]]
+echo "  Host:      ${DB_HOST}"
+echo "  Port:      ${DB_PORT}"
+echo "  User:      ${DB_USER}"
+if [[ -n "${DB_NAME}" ]]
 then
-    echo "  Database:  ${!DB_NAME}"
-    echo
+    echo "  Database:  ${DB_NAME}"
 fi
+echo
 
 #
 # Change UID / GID of backup user and settings umask.
@@ -97,11 +97,11 @@ umask ${UMASK}
 #
 #
 
-CLI_OPTIONS="-v 3 -h ${!DB_ADDR} -P ${!DB_PORT} -u root -p ${!DB_PASS}"
+CLI_OPTIONS="-v 3 -h ${DB_HOST} -P ${DB_PORT} -u ${DB_USER} -p ${DB_PASS}"
 
-if [[ -n "${!DB_NAME}" ]]
+if [[ -n "${DB_NAME}" ]]
 then
-    CLI_OPTIONS+=" -B ${!DB_NAME}"
+    CLI_OPTIONS+=" -B ${DB_NAME}"
 fi
 
 CLI_OPTIONS+=" ${OPTIONS}"