Merge branch 'update-readme' into 'master'

Updates README.md

See merge request !3

README.md

-About
-=====
+# mariadb-backup
 
-The mysql-backup Docker image will provide you a container to backup and restore a [MySQL](https://hub.docker.com/_/mysql/) or [MariaDB](https://hub.docker.com/_/mariadb/) database container.
+[![Pipeline Status](https://gitlab.com/ix.ai/mariadb-backup/badges/master/pipeline.svg)](https://gitlab.com/ix.ai/mariadb-backup/)
+[![Docker Stars](https://img.shields.io/docker/stars/ixdotai/mariadb-backup.svg)](https://hub.docker.com/r/ixdotai/mariadb-backup/)
+[![Docker Pulls](https://img.shields.io/docker/pulls/ixdotai/mariadb-backup.svg)](https://hub.docker.com/r/ixdotai/mariadb-backup/)
+[![Gitlab Project](https://img.shields.io/badge/GitLab-Project-554488.svg)](https://gitlab.com/ix.ai/mariadb-backup/)
+
+The mariadb-backup Docker image will provide you a container to backup and restore a [MySQL](https://hub.docker.com/_/mysql/) or [MariaDB](https://hub.docker.com/_/mariadb/) database container.
 
 The backup is made with [mydumper](http://centminmod.com/mydumper.html), a fast MySQL backup utility.
 
-Usage
-=====
+## Usage
 
 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.
 
-Environment variables
-=====================
-
-* `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
+## Environment variables
+| **Variable**  | **Default** | **Mandatory** | **Description**                                      |
+|:--------------|:-----------:|:-------------:|:-----------------------------------------------------|
+| `DB_HOST`     | -           | *yes*         | The host to connect to                               |
+| `DB_PASS`     | -           | *yes*         | The password for the SQL server                      |
+| `DB_NAME`     | -           | *no*          | If specified, only this database will be backed up   |
+| `DB_PORT`     | `3306`      | *no*          | The port of the SQL server                           |
+| `DB_USER`     | `root`      | *no*          | The user to connect to the SQL server                |
+| `MODE`        | `BACKUP`    | *no*          | One of `BACKUP` or `RESTORE`                         |
+| `BASE_DIR`    | `/backup`   | *no*          | Path of the base directory (aka working directory)   |
+| `RESTORE_DIR` | -           | *no*          | Name of a backup directory to restore                |
+| `BACKUP_UID`  | `666`       | *no*          | UID of the backup                                    |
+| `BACKUP_GID`  | `666`       | *no*          | GID of the backup                                    |
+| `UMASK`       | `0022`      | *no*          | Umask which should be used to write the backup files |
+| `OPTIONS`     | `-c` / `-o` | *no*          | Options passed to `mydumper` / `myloader`            |
 
 Please note the backup will be written to `/backup` by default, so you might want to mount that directory from your host.
 
-Example Docker CLI client
--------------------------
+## Example Docker CLI client
 
 To __create a backup__ from a MySQL container via `docker` CLI client:
 
 ```bash
-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
+docker run --name my-backup -e DB_HOST=mariadb -e DB_PASS=amazing_pass -v /var/mysql_backups:/backup ixdotai/mariadb-backup:latest
 ```
 
 The container will stop automatically as soon as the backup has finished.
@@ -40,30 +49,47 @@ docker start my-backup
 To __restore a backup__ into a MySQL container via `docker` CLI client:
 
 ```bash
-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
+docker run --name my-restore -e DB_HOST=mariadb -e DB_PASS=amazing_pass -v /var/mysql_backups:/backup ixdotai/mariadb-backup:latest
 ```
 
-Configuration
-=============
+## Script example
+The following example uses the image []() for MariaDB.
+To back up multiple databases, all running in docker, all labeled with `mariadb-backup`:
+```bash
+#!/usr/bin/env bash
+/bin/mkdir -p /mariadb-backup
+
+/usr/bin/docker pull ixdotai/mariadb-backup:latest
+
+for CONTAINER in $(/usr/bin/docker ps -f label=mariadb-backup --format='{{.Names}}'); do
+  DB_PASS=$(/usr/bin/docker inspect ${CONTAINER}|/usr/bin/jq -r '.[0]|.Config.Env[]|select(test("^MARIADB_ROOT_PASSWORD.*"))'|/bin/sed -n 's/^MARIADB_ROOT_PASSWORD=\(.*\)/\1/p')
+  DB_NAME=$(/usr/bin/docker inspect ${CONTAINER}|/usr/bin/jq -r '.[0]|.Config.Env[]|select(test("^MARIADB_DATABASE.*"))'|/bin/sed -n 's/^MARIADB_DATABASE=\(.*\)/\1/p')
+  DB_NET=$(/usr/bin/docker inspect ${CONTAINER}|/usr/bin/jq -r '.[0]|.NetworkSettings.Networks|to_entries[]|.key')
+  if [[ -n "${DB_PASS}" ]]; then
+    /usr/bin/docker run --rm --name ${CONTAINER}-backup -e DB_PASS=${DB_PASS} -e DB_HOST=${CONTAINER} -e DB_NAME=${DB_NAME} --network ${DB_NET} -v /mariadb-backup:/backup ixdotai/mariadb-backup:latest
+  fi
+done
+
+```
+
+## Configuration
+
 
-Mode
-----
+### Mode
 
 By default the container backups the database.
 However, you can change the mode of the container by setting the following environment variable:
 
 * `MODE`: Sets the mode of the backup container while [`BACKUP`|`RESTORE`]
 
-Base directory
---------------
+### Base directory
 
 By default the base directory `/backup` is used.
 However, you can overwrite that by setting the following environment variable:
 
 * `BASE_DIR`: Path of the base directory (aka working directory)
 
-Restory directory
------------------
+### Restore directory
 
 By default the container will automatically restore the latest backup found in `BASE_DIR`.
 However, you can manually set the name of a backup directory underneath `BASE_DIR`:
@@ -72,8 +98,7 @@ However, you can manually set the name of a backup directory underneath `BASE_DI
 
 _This option is only required when the container runs in in `RESTORE` mode._
 
-UID and GID
------------
+### UID and GID
 
 By default the backup will be written with UID and GID `666`.
 However, you can overwrite that by setting the following environment variables:
@@ -81,23 +106,20 @@ However, you can overwrite that by setting the following environment variables:
 * `BACKUP_UID`: UID of the backup
 * `BACKUP_GID`: GID of the backup
 
-umask
------
+### umask
 
 By default a `umask` of `0022` will be used.
 However, you can overwrite that by setting the following environment variable:
 
 * `UMASK`: Umask which should be used to write the backup files
 
-mydumper / myloader CLI options
--------------------------------
+### mydumper / myloader CLI options
 
 By default `mydumper` is invoked with the `-c` (compress backup) and `myloader` with the `-o` (overwrite tables) CLI option.
 However, you can modify the CLI options by setting the following environment variable:
 
 * `OPTIONS`: Options passed to `mydumper` (when `MODE` is `BACKUP`) or `myloader` (when `MODE` is `RESTORE`)
 
-Credits
-=======
+## Credits
 
 Special thanks to [confirm/docker-mysql-backup](https://github.com/confirm/docker-mysql-backup), which this project uses heavily.