Guide: Using MySQL with Databox
In this article, we will explore MySQL connection setup from the server point of view, and then we’ll connect it to Databox and make sure the connection is working. Lastly, we will create a databoard visualizing the data we’ve uploaded. All this without a single line of code – except for the MySQL query, of course.
1. Prepare Your MySQL Database and Host
To get started, you’ll need to allow remote connections from Databox’s public IP 126.96.36.199 to your database. The necessary steps to do that will depend on your database, server infrastructure and firewall. VPC IP must be able to connect to the database port directly.
We will create a user named ‘user’ with permissions to remotely access the database, aptly named ‘mydb’ in our example:
GRANT SELECT ON mydb.* TO 'user'@'188.8.131.52' IDENTIFIED BY 'securePassword';
Note: for simplicity’s sake, we have given this user a SELECT permission on all tables in our database. Permission could be given to select from one table only, or better yet: create a custom view and give permissions to select from this view only. But this is a bit beyond the scope of this document. A basic example on how to achieve this can be read here.
Now you must configure your MySQL server to listen to all IPs, since, by default, it listens to the local interface only. Open
/etc/my.cnf (this may be
/etc/mysql/my.cnf, depending on linux distro) and check that it contains:
#skip-networking # commented out! bind-address = 0.0.0.0 # Will listen on all IPs
If you’ve made any changes, restart the mysql server and it should be ready to accept remote connections.
Port 3306/TCP, which is MySQL default port, should be accessible from our VPC IP mentioned above. This must be done on your firewall. Here is the Linux iptables example:
iptables -A FORWARD -s 184.108.40.206/32 -p tcp --dport 3306 -j ACCEPT
Note: you might have to substitute FORWARD with INPUT if your Linux box has a public IP and the database runs on the host itself.
Your server should now be successfully set up to accept requests from our IP to your chosen database/table, using chosen user and password.
1.1. SSL Connection (server side setup)
It’s a good practice to secure the connection with a SSL certificate. To accomplish this, certificate must be generated and installed on a server. Here’s a quick guide on how to do this on any recent MySQL version.
We’ll use the OpenSSL command line tools in order not to tie-in with any Linux distribution too closely. Our certificate will also be self-signed, but feel free to use certificates from any certificate authority that is widely known and acknowledged.
First, let’s generate a new CA private key:
openssl genrsa 2048 > ca-key.pem
Now, we’ll generate a certificate. You will be asked some questions. Once done, you’ll have a CA key and a CA certificate:
openssl req -sha1 -new -x509 -nodes -days 3650 -key ca-key.pem > ca-cert.pem
Let’s create a new signing request now, along with a private key:
openssl req -sha1 -newkey rsa:2048 -days 730 -nodes -keyout server-key.pem > server-req.pem
Now, export the private key into a RSA private key:
openssl rsa -in server-key.pem -out server-key.pem
Finally, the server certificate can be created and signed using our CA:
openssl x509 -sha1 -req -in server-req.pem -days 730 -CA ca-cert.pem -CAkey ca-key.pem -set_serial 01 > server-cert.pem
Let’s copy the created files to our MySQL directory:
cp ca-cert.pem server-cert.pem server-key.pem /etc/mysql/
/etc/mysql/my.cnf file and add lines to the [mysqld] compartment:
ssl-ca=/etc/mysql/ca-cert.pem ssl-cert=/etc/mysql/server-cert.pem ssl-key=/etc/mysql/server-key.pem
Restart the server for new settings to come into effect.
Let’s create a user that will be allowed to connect only via SSL connection and disallowed otherwise:
GRANT ALL PRIVILEGES ON *.* TO ‘ssluser’@’%’ IDENTIFIED BY ‘SecurePassword’ REQUIRE SSL;
Feel free to restrict the user access further, the above permissions are very lax and just for example. You will probably want to restrict user to our IP only and give it only the
Now it’s a good time to test the SSL connection from a mysql client. Again, paste the three lines above to
/etc/mysql/my.cnf, but this time in [client] section. Try connecting to the server. If connection succeeded, let’s confirm we’re indeed connected via SSL, by running:
Output will show many lines, but we’re interested in this one:
SSL: Cipher in use is DHE-RSA-AES256-SHA
If “Cipher in use” is present, the SSL connection is working.
If we get a line like:
SSL: Not in use
SSL isn’t active, please go back and re-check all steps or contact support.
2. Connect Your Database to Databox
With our database ready, the next logical step is to connect it and test that it’s returning the data we want.
- Log in to the Databox web application and click on the ‘Data Manager’ tab,
- Go to the “Available Data Sources” option and find the MySQL tile.
- Hover over it with your mouse and click the ‘Connect’ button that slides up into view
- Enter your connection data in the popup and click the ‘Activate’ button. Default port 3306 is fine in most cases.
- If all went well, the popup will close shortly and you’ll get a “connected!” message.
Great! We have just successfully connected our database to Databox. In the next step, we’ll write a custom query that will regularly fetch data from your database and make it available for use in any databoard.
Troubleshooting: If you get a “wrong credentials” message, double-check your user data. If you’re stuck on ‘Activate’ for a minute or so, it’s probably having issues connecting to your database host due to firewall / server / networking issues.
2.1. SSL Setup
Once the mysql client successfully connects to the database and we’re sure SSL is working locally, it’s time to connect via Databox app.
Enter database data, then check the SSL checkbox and paste in the certificates. If using self-signed certificate, be sure to uncheck the “Verify SSL certificate” checkbox or the connection will fail.
Now paste your certificate files content in corresponding fields, SSL CA is not mandatory.
Click Activate and the connection should work. If not, check the error message and contact our support if you can’t resolve it yourself. Be sure the IP or hostname written is publicly available at least to our public IP 220.127.116.11 and is not a private IP.
3. Visualize Your Data with Databox Designer
- Choose an existing databoard or create a new one (how?)
- Choose the “Available Datablocks” icon on the left
- Drag & drop the Table block onto your databoard
- For our example, where we will have a dynamic table (the pushed metric key has dimensions/lines), we will switch to gather data from ‘Single metric’ in the properties panel on the right
Now that the database is connected, we will use the Designer to query, shape and display the data in a format that’s the most appropriate and useful for our needs:
- Select your newly created MySQL data sourcefrom the Datasource dropdown on the right
- Click on the “Metric” dropdown in the properties panel (right hand side of the screen) and choose ‘Custom Metric from Query Builder’
- Write your SQL query in the popup window that appears. For this example, we will connect to a WordPress MySQL with a basic query that returns a list of WordPress authors with their post count:
SELECT COUNT(p.ID) AS posts, u.display_name, p.date AS date FROM dbwp_users u, dbwp_posts p WHERE p.post_author = u.ID AND p.post_type = 'post' GROUP BY u.ID
- Now click on ‘Show Data,’ below. Your query result should now be displayed at the bottom, similar to this, depending on your data, of course:
Pro tip: You can rename each column (which will become a metric key in Databox) by clicking on the arrow beside it and typing in a new name.
Pro tip: You can enter a different metric key name pattern or simply leave the asterisk (*), which will create a metric key with the same name as pushed. By default, the output (target datasource, where the data gets pushed to) is already selected and is the same as your source data connection. You can use other tokens if needed.
- Once you are satisfied with the data you see, just click ‘Save Query.’
- Tada! After you have saved your custom query, you should see the data on the table. If not, check if the right data source and metric are selected. In our example it’s the ‘WordPress SQL’ data source and ‘└ posts|name’ metric, because we’re pushing posts by names. The date range should be set to ‘Today’ to see the latest data.
We have just written a custom MySQL query and displayed its results. Each hour, Databox will fetch data from this resource and store it in the selected target data source (in our example ‘WordPress SQL’).
Note: we’ve used the
AS SQL construct in our query (i.e.
AS posts). This is not mandatory, but it will describe the data as a metric key. If you use
AS date this column will represent the date and time of the value (ISO 8601 date and time standard is supported). You can leave it as it is, or choose to rename the result column. A semicolon at the end of the query is not necessary.
Troubleshooting: If you don’t see any data, double-check your SQL query and try it directly on your database. If it’s not displaying results there, you have an error somewhere in your query. Also, check that MySQL user has necessary permissions to access the database from Databox IP.
Well done! Your database is now connected to Databox, queries can be executed and then displayed on your mobile phone, TV, computer, or tablet!
Go ahead and explore further. Play around by adding more queries and blocks, or explore different types of visualizations. Make that perfect databoard you’ve always needed but didn’t know how to create. Now you can! Clean and professional, right at your fingertips. Only data that matters, without clutter. The possibilities are truly endless.