WordPress with Docker

We are going to create a MariaDB container and two WordPress containers (for the domains wp3.user1.fs.al and wp4.user1.fs.al). And because the WP containers need to communicate with the DB container, we will also create a docker (virtual) network, where all the three containers will be connected.

We are going to use the existing nginx as a reverse proxy for these two sites. Ideally, we should also containerize the reverse proxy, but let's keep it simple for the time being.

1. Create a network

docker network ls
docker network create wpnet
docker network ls
docker network inspect wpnet | less

2. Create a MariaDB container

We can download and use the official mariadb image:
```
docker search mariadb | less
docker pull mariadb
docker image ls
docker image history mariadb | less
```
It is official because it is maintained by the MariaDB foundation.

Let's create a directory for this container:

mkdir -p /var/docker/db1
cd /var/docker/db1

Create a container:

cat <<'_EOF_' > create.sh
#!/bin/bash -x

mkdir -p data
docker create \
    --name db1 \
    --hostname mariadb \
    --network wpnet \
    --network-alias mariadb1 \
    --mount type=bind,source=$(pwd)/data,destination=/var/lib/mysql \
    --restart unless-stopped \
    --env MARIADB_ALLOW_EMPTY_ROOT_PASSWORD=1 \
    mariadb:latest
_EOF_

nano create.sh
chmod +x create.sh
./create.sh
docker ps -a

Start and test the container:

docker start db1
docker ps
docker logs db1 -f
ls data/

docker exec -it db1 mariadb
show databases;
exit

3. Install WP3

Let's create a directory for it:

mkdir -p /var/docker/wp3
cd /var/docker/wp3/

Create also a MariaDB database and user:

docker exec -it db1 mariadb

CREATE DATABASE wp3db;
show databases;

CREATE USER 'wp3user'@'%' IDENTIFIED BY 'wp3pass';
select user, host from mysql.user;

GRANT ALL ON wp3db.* TO 'wp3user'@'%';
show grants for 'wp3user'@'%';

FLUSH PRIVILEGES;
exit;

We can download and use the official wordpress image:

docker search wordpress | less
docker pull wordpress
docker image ls
docker image history wordpress | less

This image includes Apache2, PHP and the WP application files.

Create a container:

cat <<'_EOF_' > create.sh
#!/bin/bash -x

mkdir -p www
docker create \
    --name wp3 \
    --hostname wp3 \
    --network wpnet \
    --publish 127.0.0.1:8083:80 \
    --mount type=bind,source=$(pwd)/www,destination=/var/www/html \
    --env WORDPRESS_DB_HOST=mariadb1 \
    --env WORDPRESS_DB_NAME=wp3db \
    --env WORDPRESS_DB_USER=wp3user \
    --env WORDPRESS_DB_PASSWORD=wp3pass \
    --restart unless-stopped \
    wordpress:latest
_EOF_

nano create.sh
chmod +x create.sh
./create.sh
docker ps -a

Start it:

docker start wp3
docker logs wp3 -f
ls
ls www/
nano www/wp-config.php

Test it with w3m:

apt list w3m
apt install w3m
w3m http://127.0.0.1:8083    # use 'q' to exit

Create a new site on the reverse proxy:

cd /etc/nginx/sites-available/
cp wp2 wp3
sed -i wp3 -e 's/wp2/wp3/g'
nano wp3

Edit wp3 and make sure that the proxy_pass line looks like this:

proxy_pass http://127.0.0.1:8083;

Enable this site:

cd ../sites-enabled/
ln -s ../sites-available/wp3 .

nginx -t

Get an SSL cert for the new site:

certbot certonly \
    --webroot -w /var/www \
    -d wp3.user1.fs.al,www.wp3.user1.fs.al \
    --dry-run
certbot certonly \
    --webroot -w /var/www \
    -d wp3.user1.fs.al,www.wp3.user1.fs.al \
    -m dashohoxha@gmail.com \
    --agree-tos
certbot certificates

Reload nginx:

nginx -t
systemctl reload nginx

Open in browser https://wp3.user1.fs.al and complete the installation wizard.

4. Install WP4

Create a directory for it:

mkdir -p /var/docker/wp4
cd /var/docker/wp4/

Create a MariaDB database and user:

cat <<'_EOF_' > db-init.sh
#!/bin/bash -x

DBNAME="wp4db"
DBUSER="wp4user"
DBPASS="wp4pass"

DBCONTAINER="db1"
mariadb="docker exec -i $DBCONTAINER mariadb"

cat <<EOF | tee /dev/tty | $mariadb
    create database $DBNAME;
    create user '$DBUSER'@'%' identified by '$DBPASS';
    grant all on $DBNAME.* to '$DBUSER'@'%';
    flush privileges;
EOF

_EOF_

nano db-init.sh
chmod +x db-init.sh
./db-init.sh
echo 'show databases;' \
    | docker exec -i db1 mariadb

Create a WP container:

cat <<'_EOF_' > create.sh
#!/bin/bash -x

DBHOST='mariadb1'
DBNAME='wp4db'
DBUSER='wp4user'
DBPASS='wp4pass'

mkdir -p www
docker create \
    --name wp4 \
    --hostname wp4 \
    --network wpnet \
    --publish 127.0.0.1:8084:80 \
    --mount type=bind,source=$(pwd)/www,destination=/var/www/html \
    --env WORDPRESS_DB_HOST=$DBHOST \
    --env WORDPRESS_DB_NAME=$DBNAME \
    --env WORDPRESS_DB_USER=$DBUSER \
    --env WORDPRESS_DB_PASSWORD="$DBPASS" \
    --restart unless-stopped \
    wordpress:latest
_EOF_

nano create.sh
chmod +x create.sh
./create.sh
docker ps -a

Start it:

docker start wp4
docker logs wp4 -f
ls www/
ls -al www/

w3m http://127.0.0.1:8084

Create a new nginx site:

cd /etc/nginx/sites-available/
cp wp3 wp4
sed -i wp4 -e 's/wp3/wp4/g' -e 's/8083/8084/'
nano wp4

cd ../sites-enabled/
ln -s ../sites-available/wp4 .

nginx -t

Get an SSL cert and reload nginx:

domain=wp4.user1.fs.al
email=dashohoxha@gmail.com

certbot certonly --webroot -w /var/www \
    -d $domain,www.$domain --dry-run

certbot certonly --webroot -w /var/www \
    -d $domain,www.$domain -m $email --agree-tos

certbot certificates

nginx -t
systemctl reload nginx

Open in browser https://wp4.user1.fs.al and complete the installation wizard.

5. Maintenance

Logs:

docker logs db1 -f
docker logs wp4 -f

5.1 `wp-cli`

The tool wp-cli is crucial for the mantenance of a WP site. Let's make a script that runs it:

cat <<'_EOF_' > /var/docker/wp4/wp-cli.sh
#!/bin/bash

DBHOST='mariadb1'
DBNAME='wp4db'
DBUSER='wp4user'
DBPASS='wp4pass'

docker run -it --rm \
    --user 33:33 \
    --volumes-from wp4 \
    --network container:wp4 \
    --env WORDPRESS_DB_HOST=$DBHOST \
    --env WORDPRESS_DB_NAME=$DBNAME \
    --env WORDPRESS_DB_USER=$DBUSER \
    --env WORDPRESS_DB_PASSWORD="$DBPASS" \
    --env HOME=/tmp \
    wordpress:cli "$@"
_EOF_

cd /var/docker/wp4/
chmod +x wp-cli.sh
./wp-cli.sh --help
./wp-cli.sh user list

5.2 Backup

Let's create a backup script:

cat <<'_EOF_' > ~/wp4-backup.sh
#!/bin/bash -x

systemctl stop nginx

cd /var/docker/wp4/
./wp-cli.sh db export db.sql
cd ..
tar cfz wp4-$(date +%Y%m%d).tgz wp4/
mv *.tgz ~/

systemctl start nginx
_EOF_

Test it:

nano ~/wp4-backup.sh
chmod +x ~/wp4-backup.sh
~/wp4-backup.sh
ls -lh ~/
tar tvfz ~/wp4-20250210.tgz | less

5.3 Restore

Uninstall WP4:

cat <<'_EOF_' > ~/wp4-remove.sh
#!/bin/bash -x

docker stop wp4
docker rm wp4
rm -rf /var/docker/wp4/

DBNAME="wp4db"
DBUSER="wp4user"
DBPASS="wp4pass"

DBCONTAINER="db1"
mariadb="docker exec -i $DBCONTAINER mariadb"
cat <<EOF | tee /dev/tty | $mariadb
    revoke all privileges, grant option from '$DBUSER'@'%';
    drop user '$DBUSER'@'%';
    drop database $DBNAME;
EOF
_EOF_

nano ~/wp4-remove.sh
chmod +x ~/wp4-remove.sh
~/wp4-remove.sh

Restore from the backup:

cd /var/docker/
tar xfz ~/wp4-*.tgz
ls
cd wp4/

ls
./db-init.sh
./create.sh
docker ps -a
docker start wp4
# open https://wp4.user1.fs.al in browser and finish the installation

# import the DB backup
ls www/
ls -lh www/db.sql
./wp-cli.sh db import db.sql

5.4 Update

Update WP files:

systemctl stop nginx

# Update WordPress core
./wp-cli.sh core version
./wp-cli.sh core update
./wp-cli.sh core update-db

# Update all plugins
./wp-cli.sh plugin update --all

# Update all themes
./wp-cli.sh theme update --all

# Clear cache
./wp-cli.sh cache flush

systemctl start nginx

Update docker image:
```
docker pull wordpress:latest
docker image ls

docker stop wp4
docker rm wp4

cd /var/docker/wp4/
./create.sh
docker start wp4
```
This is the equivalent of apt update && apt upgrade for docker containers.

We destroy and recreate the container, however the DB and the WP files will be the same as before, because they are outside the container.

1. Create a network​

2. Create a MariaDB container​

3. Install WP3​

4. Install WP4​

5. Maintenance​

5.1 wp-cli​

5.2 Backup​

5.3 Restore​

5.4 Update​