How to use GCP MySQL Cloud SQL instances

from creation over connection to deletion

Posted by Pascal Landau on 2023-04-13 10:00:00

In this blog post I'll summarize my experience with GCP MySQL Cloud SQL instances. Cloud SQL is the managed relational database solution from Google Cloud Platform and was mentioned in Deploy dockerized PHP Apps to production on GCP via docker compose as a POC as the "better" way to deal with databases in a dockerized application (compared to running a database via docker).

What will you learn?
I'll explain the basic steps to create a fresh MySQL instance, show different ways to connect to it (Cloud Shell, locally "from your laptop" and from a VM within GCP) and finally how to delete the instance. Every process is done through the Cloud Console UI and recorded as a short video as a visual aid. As in the GCP "primer" tutorial, this article ends with the commands to achieve the same things also via the gcloud CLI.

Table of contents

Setup Cloud SQL

GCP Cloud Console Cloud SQL UI

The managed solution for relational databases from GCP is called Cloud SQL and provides multiple database technologies - including mysql. In the Cloud Console UI it is managed via the SQL UI that allows us to create and manage instances.

Create a new mysql instance

To get started, we need to enable the following APIs:

Creating a new instance from the Create a MySQL instance UI is pretty straight forward and well documented in the GCP MySQL Guide: Create instances, though there are some configuration options under "Customize your instance" that I want to mention:

  • Machine type > Machine type: For testing purposes, I recommend choosing a "Shared core" option here (e.g. 1 vCPU, 0.614 GB) to keep the costs to a minimum
  • Connections > Instance IP assignment: For now we'll go with a "Public IP", because setting up private connectivity requires some additional configuration
  • Data Protection > Instance deletion protection: When the option Enable deletion protection is enabled, the instance cannot be deleted. The option must first be disabled before this is possible (see also Delete a Cloud SQL instance).

FYI: Unfortunately, there is no "EQUIVALENT COMMAND LINE" button as it was the case when creating the Compute Instance - which would have come in handy for creating the instance via gcloud cli.

Once everything is configured, click the "Create Instance" button. The actual creation can take quite some time (I've experienced times from a couple of minutes to half an hour).

Connecting to a MySQL Cloud SQL instance

I'll explain 3 different ways of connecting to a MySQL Cloud SQL instance:

  • via Cloud Shell (requires a public instance IP)
  • "locally" from your laptop (requires a public instance IP)
  • from a Compute Instance VM on GCP (requires a private instance IP)

Out of scope:

As always, GCP has also an extensive documentation on the various connection methods available at GCP MySQL Guide: About connection options.

Connecting to the mysql instance with Cloud Shell via public IP

The easiest way to connect is through Cloud Shell. GCP will spin up a VM "behind the scenes" that we can control via shell session in the browser. Navigate to the management UI of the instance at$instanceName/overview

# e.g. for an instance named 'mysql-1'

and click the "OPEN CLOUD SHELL" button in panel "Connect to this instance".

Please note the

Allowlisting your IP for incoming connection for 5 minutes...working.

step in the video: GCP handles all the "networking stuff" to make the connection possible for us.

Connecting to the mysql instance via public IP

Even though the instance has a public IP address ( in this case, as shown in the previous video), we can't simply connect to it via

$ mysql -u root -p12345678 -h
# ... the request will simply time out

due to firewall rules:

Note: The authorized networks list is implemented on the Cloud SQL instance VM by a local firewall. Learn more about managing connections.

If we want to connect from e.g. our own computer, we need to first create a so-called "Authorized network" as described in the GCP MySQL Guide: Authorize with authorized networks.

For testing purposes I'll retrieve my own public IP address via wget -q -O -

$ wget -q -O -

and edit the mysql instance to add only this IP address as an Authorized network. The following video shows that the connection isn't possible before I added the Authorized network but will be afterwards.

CAUTION: Please regard this only as a proof of concept. It's not really a viable process to retrieve your own public IP in order to allowlist it "manually". It might be "okay" though, if you are using a VPN with a static IP. However, for the Docker PHP tutorial we'll not use a public IP address at all, because our mysql instance should only be available for our application VMs.

Connecting to the mysql instance via private IP

Having the MySQL Cloud SQL instance exposed via public IP is generally not advised and always carries a certain security risk. Thus, it is desirable to only allow connections via private IP. Be aware that this has some caveats, though (see section Caveats for using a private IP only).

In order to connect to the MySQL Cloud SQL instance via private IP (i.e. from a Compute Instance VM), we must first understand how the network configuration of the "managed" products of GCP is set up. This is explained in detail in the GCP MySQL Guide: Learn about using private IP. In short:

  • we use a private network that allows all of our VMs to communicate
  • such a network is called VPC (virtual private cloud)
  • since "we" (as a user of GCP) create and manage our application VMs ourselves, the VMs live "directly" in this network
  • the managed services like Cloud SQL are "doing their own thing", i.e. GCP takes care of all the networking stuff but keeps it isolated from "our" network
  • in consequence, our VMs cannot talk to a MySQL Cloud SQL instance, because it lives on a different network
  • fortunately, there is a technique called VPC peering that can connect different VPCs and thus enable communication
  • to make this work, we need to "reserve" a range of IPs in "our" VPC and make it available to Cloud SQL by peering with the Google Cloud Platform Service Producer

See also the Example in the MySQL Guide: Learn about using private IP

Connecting to Cloud SQL via private IP through VPC peering

Concrete steps to connect via private IP

In short:

  • enable the Service Networking API
  • navigate to the "default" network UI
    • give it a name, e.g. "google-internal-services"
    • and select option "Automatic" with a prefix length of 16 (this determines the number of possible Cloud SQL instances, see also the docs on Allocated range size)
    • choose "Google Cloud Platform" in the "Connected service producer" drop down field and select the "google-internal-services" range that we just created for the "Assigned allocation" drop down field
  • once the "peering" is done, you can also observe a corresponding entry in the VPC network peering UI VPC peering connection with
  • create a new MySQL Cloud SQL instance (or modify an existing one)
    • under Connections > Instance IP assignment unselect "Public IP" and select "Private IP" select the network "default"
    • Note: The instance is being shutdown and restarted, i.e. this operation will lead to a service disruption and can take up to several minutes
  • once the update is done, navigate to the MySQL Cloud SQL UI of the instance and find the private IP in panel "Private IP address"

To test the connectivity from a VM, perform the following steps:

See also the GCP MySQL docs:

Caveats for using a private IP only

But tbh, I would probably rather create an SSH tunnel with the gcloud cli on a small Compute Instance VM via

gcloud compute ssh $computeInstanceName --zone=$computeInstanceZone -- -N -L 3306:$mysqlInstanceIp:3306

Delete a MySQL Cloud SQL instance

Once again, GCP is doing a great job documenting the process to delete a MySQL Cloud SQL instance in the GCP MySQL Guide: Delete instances.

Please give it a read as there is at least once thing that I found quite un-intuitive: Even after deleting an instance, the name of the deleted instance is "blocked" for a week. In my case, this created some problems, because I was making assumptions about the name in other parts of my code (e.g. I was expecting that the name of the instance is always mysql), but when playing around with Cloud SQL I learned too late, that I couldn't re-use the name after deleting the instance for testing purposes.

As of 2022-09-21 the above statement is no longer true - instance names are now immediately available after deletion:

> Cloud SQL allows the re-use of an instance name immediately after the instance is deleted.

Source: GCP Release Notes from 2022-09-21

Note: If "Deletion protection" is enabled, it needs to be disabled first - which is usually quite a fast operation.

See the following video for a visual representation of the process (please ignore the "blocked" instance name issue at the end):

Using the gcloud CLI

Even though I like using the UI to "explore and understand" how things are working, the goal is always a more "unattended" approach, e.g. via the gcloud cli. Since I'm gonna use a MySQL Cloud SQL instance as replacement for a mysql docker container for the next part of the Docker PHP tutorial, I'll focus on creating an instance with a private IP address only, update the root password and set up a default database.

The following commands assume that you have created a master service account with owner permissions and activated it for glcoud with a default project. See also Preconditions: Project and Owner service account

Activate the service account

gcloud auth activate-service-account --key-file=./gcp-master-service-account-key.json --project=${project_id}

Enable the necessary APIs

gcloud services enable \ \ \ \ is necessary to create the IP range allocation in the next step.

Create an IP range allocation


gcloud compute addresses create "${private_ip_range_name}" \
  --global \
  --purpose=VPC_PEERING \
  --prefix-length=16 \
  --addresses="${ip_range_network_address}" \
  --description="Peering range for GCP Services" \

The --addresses flag can be used to define the network address of the defined range. If it is not given, GCP will choose a random one.

Create the VPC peering with


gcloud services vpc-peerings connect \ \
  --ranges="${private_ip_range_name}" \

Create the mysql instance

Caution: The --allocated-ip-range-name option is currently (2023-04-13) only available in the beta tools of the gcloud cli. You might need to install them first via gcloud components install beta.

version="MYSQL_8_0" # see

gcloud beta sql instances create "${mysql_instance_name}" \
  --database-version="${version}" \
  --cpu="${cpus}" \
  --memory="${memory}" \
  --region="${region}" \
  --network="${network}" \
  --no-assign-ip \

The --no-assign-ip flag is responsible for not assigning a public IP.

Set the root password


gcloud sql users set-password root \
  --host=% \
  --instance "${mysql_instance_name}" \
  --password "${root_password}"

Using --host=% will allow access from any remote host, see docu for the --host parameter

Cloud SQL user's host name expressed as a specific IP address or address range. % denotes an unrestricted host name. Applicable flag for MySQL instances; ignored for all other engines.

FYI: Instead of "root", we could also use a different username like "application_user" and MySQL would create that user automatically with the given password (without any privileges).

Create a default database


gcloud sql databases create "${default_database}" \
  --instance="${mysql_instance_name}" \
  --charset=utf8mb4 \

Wrapping up

Congratulations, you made it! If some things are not completely clear by now, don't hesitate to leave a comment. You are now able to manage MySQL databases on GCP via the UI as well as via the gcloud cli.

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