updated readme

README.md

@@ -1,29 +1,30 @@
-[![Build Status](https://drone.asperti.com/api/badges/paspo/docker-mariadb-backup-slave/status.svg)](https://drone.asperti.com/paspo/docker-mariadb-backup-slave)
-
-
 # docker-mariadb-backup-slave
 
-Setup a mariadb slave server with automysqlbackup
+[![Build Status](https://drone.asperti.com/api/badges/paspo/docker-mariadb-backup-slave/status.svg)](https://drone.asperti.com/paspo/docker-mariadb-backup-slave)
 
+Setup a mariadb slave server with automysqlbackup
 
 ## Parameters
 
 ### SERVER_ID
+
 This is used to customize slave server ID. The default value is 33. You should use an unique ID for each server.
 
 ### READONLY
+
 When set to **1**,  the slave server is set as readonly. This is the default. If you set this variable to something different, the database will be read/write.
 
 ### REPLICATE_DO_DB
-This is used to specify a single database to backup. It is generally advised to set this variable to the database name you want to backup.
 
+This is used to specify a single database to backup. It is generally advised to set this variable to the database name you want to backup.
 
 ## How to setup a mysql slave for backup
 
 ### Configure the master node
+
 Examine all mariadb config files, they're usually located in **/etc/mysql/**. You must have these instructions:
 
-```
+```ini
 [mysqld]
 server_id = 1
 log_bin
@@ -41,7 +42,7 @@ After these modifications, restart mariadb.
 
 Execute this statement on the master node:
 
-```
+```sql
 grant replication slave on *.* to repluser@backupslave.host identified by 'aRandomPassword'; flush privileges;
 ```
 
@@ -51,7 +52,7 @@ Replace **repluser**, **backupslave.host**, **aRandomPassword** with something m
 
 We use docker-compose here, but you can do the same with plain docker. Here's a sample **docker-compose.yaml** file:
 
-```
+```yaml
 version: "3"
 services:
 
@@ -69,12 +70,14 @@ services:
 ```
 
 Start the container:
-```
+
+```bash
 docker-compose up -d
 ```
 
 Create the database:
-```
+
+```bash
 docker exec my-container sh -c 'echo "create database aWordpressDatabase;" | exec mysql -uroot -p"$MYSQL_ROOT_PASSWORD"'
 ```
 
@@ -82,7 +85,8 @@ docker exec my-container sh -c 'echo "create database aWordpressDatabase;" | exe
 
 To obtain a consistant slave, you first have to freeze the master, and then transfer the data.
 Execute this on the master:
-```
+
+```sql
 FLUSH TABLES WITH READ LOCK; 
 show master status;
 ```
@@ -92,6 +96,7 @@ show master status;
 Take note of file and position, we'll need these informations later.
 
 ### Import initial data
+
 We have two ways to copy the data from the master to the slave: we'll call these "live" and "classic".
 The classic way is the usual mysqldump + file transfer + import.
 The live way is dump + import at the same time, without an intermediate file.
@@ -99,47 +104,62 @@ The live way is preferred when you have small databases (less than 5Gb) and a go
 The classic way is preferred when you have a big database because it locks the database for less time.
 
 ### Import initial data (live version)
+
 Now, we need to import the backup from the master, so as we started the slave as readwrite, we can now do this on the slave:
 
-```
+```bash
 docker exec my-container sh -c 'mysqldump -C --lock-tables=false --quick -u repluser -h master.host --password="aRandomPassword" aWordpressDatabase | mysql -u root -p"$MYSQL_ROOT_PASSWORD" aWordpressDatabase'
 ```
 
 Replace **my-container**, **repluser**, **master.host**, **aRandomPassword**, **aWordpressDatabase** with the correct values.
 
 Now that the slave has got some data, we can release the lock in the master:
-```
+
+```bash
 UNLOCK TABLES;
 ```
 
 ### Import initial data (classic version)
+
 In the master we run mysqldump in a shell:
-```
+
+```bash
 mysqldump -u root -p aWordpressDatabase | gzip > thedump.sql.gz
 ```
+
 When the export is finished, we can let the master resume his work, by issuing this command in the previous mysql session:
-```
+
+```bash
 UNLOCK TABLES;
 ```
+
 We can proceed to transfer the dump file to the slave; use the method you prefer.
 On the slave, copy the dump file in the running container, like this:
-```
+
+```bash
 docker cp thedump.sql.gz my-container:/thedump.sql.gz
 ```
+
 Then we import it:
-```
+
+```bash
 docker exec my-container sh -c 'zcat /thedump.sql.gz | mysql -u root -p"$MYSQL_ROOT_PASSWORD" aWordpressDatabase'
 docker exec my-container sh -c 'rm /thedump.sql.gz'
 ```
+
 Replace **my-container**, **aWordpressDatabase** with the correct values.
 
 ### Start the slave
+
 Open a mysql console in the slave:
-```
+
+```bash
 docker exec -ti my-container sh -c 'mysql -u root -p"$MYSQL_ROOT_PASSWORD" aWordpressDatabase'
 ```
+
 And configure the replication:
-```
+
+```sql
 STOP SLAVE;
 RESET SLAVE;
 CHANGE MASTER TO 
@@ -153,12 +173,16 @@ CHANGE MASTER TO
   MASTER_CONNECT_RETRY=10;
 START SLAVE;
 ```
+
 ### Check replication status
-```
+
+```bash
 docker exec -ti my-container sh -c 'mysql -u root -p"$MYSQL_ROOT_PASSWORD" aWordpressDatabase -e "SHOW SLAVE STATUS\G;"'
 ```
+
 Example output:
-```
+
+```sql
 *************************** 1. row ***************************
                Slave_IO_State: Waiting for master to send event
                   Master_Host: master.host
@@ -209,18 +233,23 @@ Master_SSL_Verify_Server_Cert: No
                 Parallel_Mode: conservative
 1 row in set (0.00 sec)
 ```
+
 In a normal condition, **Slave_IO_Running** and **Slave_SQL_Running** should be **Yes**: this means that the communication between master and slave is ok and no sync error has occourred. **Seconds_Behind_Master** is usually 0, except wen the communication has just been established and the slave has to catch up with the master. This situation usually resolves in some time.
 
 ### Make the slave read-only
+
 For a safety measure, we're enabling read-only mode for the slave: we don't have to run any query on this host, we're just using it for scheduled backups.
 Reopen **docker-compose.yaml**, change **READONLY=0** to **READONLY=1** and restart the container:
-```
+
+```bash
 docker-compose up -d
 ```
 
 ## How to use different mariadb version
-The default is mariadb 10.4.
+
-If you want, you can use mariadb 10.3, 10.2 or 10.1 by changing this line in **docker-compose.yaml**:
+The default is mariadb 10.5.
-```
+If you want, you can use mariadb 10.4, 10.3, or 10.2 by changing this line in **docker-compose.yaml**:
+
+```yaml
   image: docker.asperti.com/paspo/mariadb-backup-slave:maria-10.1
 ```