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Run Database in GitHub Actions, Persisting Data to S3, and Access it Publicly

· 7 min read
earayu
WeScale Contributor

When it comes to running a database for development, testing, demos, or short-lived workloads, cost and complexity can be big headaches. Traditional database hosting—like a VPS, a cloud VM, or a managed service—comes with ongoing costs, storage expenses, and configuration overhead. You often end up paying for resources even when you're not using them.

But what if you could spin up a database only when you need it, leverage cheap (or free) object storage for persistence, and tear it down afterward at nearly zero cost, without losing data? One possible approach is to use GitHub Actions as an ephemeral compute environment, combined with S3 (or an S3-compatible service) as persistent storage. With a secure tunnel, you can even access it publicly.

Important Note on Usage: This approach should be used only for short-term integration tests, temporary demos, or quick development tasks. Do not abuse GitHub Actions by running a database continuously or using it as a long-term service platform. GitHub Actions is designed primarily for CI/CD, not as a free computing resource for persistent services. If you need continuous or long-running database hosting, please consider other services or set up a Self-Hosted GitHub Runner in an environment you control, ensuring compliance with GitHub’s usage policies.

Key Idea

The core concept is:

  1. Ephemeral Compute from GitHub Actions: Spin up a MySQL-compatible database only on-demand as part of a CI/CD or testing workflow.
  2. S3-Compatible Storage for Persistence: Store all database data in object storage like AWS S3 or Cloudflare R2. When the ephemeral environment ends, you still have your data safely stored off-runner.
  3. Tunneling for Public Access: Temporarily expose the database to the internet for tests or demos.
  4. Short-Term Use Only: The database runs during the workflow execution window. Once done, the workflow ends and the ephemeral compute resource is freed. This is not intended as a permanent hosting solution.

Want it entirely free? Consider an S3-compatible service like Cloudflare R2 with a generous free tier.

Use Cases

  • Integration Testing in CI/CD: Spin up a real MySQL-compatible environment for test runs, then shut it down.
  • Temporary Demos: Need a quick, shareable DB instance for a one-off demo? Perfect.
  • Short-Term Development: Quickly test new code against a real DB environment without maintaining a full-time service.

Not Recommended For:

  • Long-term database hosting or production workloads.
  • Maintaining an always-on public database endpoint.
  • Circumventing GitHub Actions usage policies.

If you have longer-running needs, consider setting up a Self-Hosted Runner where you manage resources and adhere to the appropriate usage rules.

Example GitHub Actions Workflow

Below is an example GitHub Actions workflow that demonstrates this approach. The workflow briefly spins up a WeSQL database, uses object storage for persistence, and provides temporary tunnel access. If you want to use this workflow, you can follow the steps in the README.

name: Start WeSQL Cluster

on:
workflow_dispatch:

jobs:
build:
runs-on: ubuntu-latest

steps:
- name: Configure AWS CLI
run: |
aws configure set aws_access_key_id ${{ secrets.WESQL_OBJECTSTORE_ACCESS_KEY }}
aws configure set aws_secret_access_key ${{ secrets.WESQL_OBJECTSTORE_SECRET_KEY }}
aws configure set default.region ${{ secrets.WESQL_OBJECTSTORE_REGION }}

- name: Start WeSQL Server
run: |
export WESQL_OBJECTSTORE_BUCKET=${{ secrets.WESQL_OBJECTSTORE_BUCKET }}
export WESQL_OBJECTSTORE_REGION=${{ secrets.WESQL_OBJECTSTORE_REGION }}
export WESQL_OBJECTSTORE_ACCESS_KEY=${{ secrets.WESQL_OBJECTSTORE_ACCESS_KEY }}
export WESQL_OBJECTSTORE_SECRET_KEY=${{ secrets.WESQL_OBJECTSTORE_SECRET_KEY }}

docker run -itd --network host --name wesql-server \
-p 3306:3306 \
-e MYSQL_CUSTOM_CONFIG="[mysqld]\n\
port=3306\n\
log-bin=binlog\n\
gtid_mode=ON\n\
enforce_gtid_consistency=ON\n\
log_slave_updates=ON\n\
binlog_format=ROW\n\
objectstore_provider='aws'\n\
repo_objectstore_id='tutorial'\n\
objectstore_bucket='${WESQL_OBJECTSTORE_BUCKET}'\n\
objectstore_region='${WESQL_OBJECTSTORE_REGION}'\n\
branch_objectstore_id='main'" \
-v ~/wesql-local-dir:/data/mysql \
-e WESQL_CLUSTER_MEMBER='127.0.0.1:13306' \
-e MYSQL_ROOT_PASSWORD=${{ secrets.WESQL_ROOT_PASSWORD }} \
-e WESQL_OBJECTSTORE_ACCESS_KEY=${WESQL_OBJECTSTORE_ACCESS_KEY} \
-e WESQL_OBJECTSTORE_SECRET_KEY=${WESQL_OBJECTSTORE_SECRET_KEY} \
apecloud/wesql-server:8.0.35-0.1.0_beta4.38

- name: Wait for MySQL port
run: |
for i in {1..60}; do
if nc -z localhost 3306; then
echo "MySQL port 3306 is ready!"
exit 0
fi
echo "Waiting for MySQL port 3306..."
sleep 5
done
echo "Timeout waiting for MySQL port 3306"
exit 1

- name: Start and parse Serveo tunnel
run: |
# Just a neat trick: start a tunnel and parse out the assigned port
nohup ssh -o StrictHostKeyChecking=no -R 0:localhost:3306 serveo.net > serveo.log 2>&1 &
sleep 5

TUNNEL_LINE=$(grep 'Forwarding TCP' serveo.log || true)
if [ -z "$TUNNEL_LINE" ]; then
echo "No forwarding line found"
exit 1
fi

HOST="serveo.net"
PORT=$(echo "$TUNNEL_LINE" | sed 's/.*Forwarding TCP connect from .*:\([0-9]*\)/\1/')

echo "MySQL Public Access:"
echo "Host: $HOST"
echo "Port: $PORT"
echo "Connect: mysql -h $HOST -P $PORT -u root -p${{ secrets.WESQL_ROOT_PASSWORD }}"

echo "HOST=$HOST" >> $GITHUB_ENV
echo "PORT=$PORT" >> $GITHUB_ENV

- name: Write Connection Info to S3
run: |
# Just a convenience: store connection info in S3 so you can find it later
cat << EOF > connection_info.txt
host=$HOST
port=$PORT
username=root
password=${{ secrets.WESQL_ROOT_PASSWORD }}
mysql_cli="mysql -h $HOST -P $PORT -u root -p${{ secrets.WESQL_ROOT_PASSWORD }}"
EOF

aws s3 cp connection_info.txt s3://${{ secrets.WESQL_OBJECTSTORE_BUCKET }}/connection_info.txt
echo "Connection info is now in s3://${{ secrets.WESQL_OBJECTSTORE_BUCKET }}/connection_info.txt"

- name: Keep session running
run: |
# Keep the workflow alive so the database stays accessible.
echo "Press Ctrl+C or cancel the workflow when done."
tail -f /dev/null

Breakdown of the Workflow (Tips & Tricks)

  • Using S3 or R2: By default, this example shows AWS S3. But since WeSQL just needs an S3-compatible API, you could easily switch to Cloudflare R2’s free tier. That could make the whole setup cost zero, no matter how often you run it.
  • Tunneling: Serveo is a neat trick. By using SSH, we ask Serveo to forward a random high port on their server to our MySQL port on the ephemeral runner. Suddenly, anyone on the internet can connect to our ephemeral DB—cool, right? You can replace Serveo with other tunneling services such as ngrok as you like, but Serveo is simple and free.
  • Persistence: Because all data lives in S3 (or R2), the DB can vanish and reappear as needed with full persistence. Think of it as "serverless" MySQL.
  • Storing Connection Info in S3: Another trick. Instead of always reading logs, you can fetch the connection details from S3. This is handy if you want to programmatically retrieve connection info for some automation elsewhere.

Connecting to the Database

After this workflow runs, check the Actions log for the Host and Port. On your local machine, just do:

mysql -h serveo.net -P <PORT> -u root -p<YOUR_PASSWORD>

images/use-github-actions-as-a-database/actions_run_page.png

Data Persistence & Restarting

The big win here: When the runner dies, you lose the container, but not the data. Next time you run the workflow, WeSQL pulls data back from your chosen object storage provider (AWS S3, R2, or any S3-compatible service). This means you can treat your DB like a long-lived environment—even though it’s technically ephemeral compute.

You can see all your data in S3 bucket: images/use-github-actions-as-a-database/s3_page.png

A Note on Security

  • The tunnel is public. Use a strong password, maybe restrict access (if the service supports it), and rotate credentials when done.
  • Keep AWS and DB credentials in GitHub Secrets, not in your code.
  • If you handle sensitive data, consider TLS and additional security layers.

Conclusion

This approach challenges the traditional “rent a server and keep it running” model for databases. Using GitHub Actions as ephemeral compute plus S3 for storage, you get a “serverless-ish” database that runs only when you want it, free of charge, and is still accessible from anywhere on the net.

It’s a neat hack. Give it a try next time you need a throwaway or on-demand DB environment. You might never go back to your old ways of spinning up costly VMs or managed instances just to show someone a quick demo or run a batch of tests.

The Shift to S3 - Every Database Will Be Rearchitected for S3 in the Next Few Years

· 7 min read
Wei Cao
Founder at ApeCloud

In recent years, we’ve seen a profound shift in how databases handle storage, with more and more systems transitioning to S3 (or S3-compatible object storage) as their primary storage backend. This trend is not isolated to any single type of database but is happening across the spectrum— from OLAP data warehouses, to streaming systems, to OLTP databases, and even embedded databases. It’s becoming increasingly clear that object storage will be the future of database architecture, and in the next two to three years, we can expect nearly every database to be rearchitected to utilize S3 or similar services.

Early Adopters: OLAP Data Warehouses

The shift to S3 started in the OLAP (Online Analytical Processing) domain. Object storage, with its unlimited scalability, pay-as-you-go pricing, and high read&write bandwidth, is a perfect fit for the I/O-heavy, large-scale data operations typical of OLAP systems.

Take Snowflake, for example. Snowflake was one of the earliest products to adopt S3 as its backend storage, revolutionizing how data warehouses could scale in the cloud. One of the biggest advantages Snowflake gained from adopting S3 was the ability to separate compute from storage. This separation enabled Snowflake to offer elastic scaling of compute resources, allowing users to independently scale compute nodes as needed. This architecture also supports features like virtual data warehouses, where multiple teams or workloads can operate on the same underlying data without resource contention. By leveraging S3, Snowflake not only achieved cost savings and reliability but also unlocked powerful cloud-native capabilities.

Another player, Rockset also embraced S3 for its data storage, achieving compute-storage separation. It uses RocksDB as its storage engine, storing data on S3 to provide data durability, while leveraging a tiered storage architecture to offer better cost efficiency.

Beyond OLAP: Streaming Systems and Kafka Alternatives

The shift to S3 is not limited to OLAP databases. Even streaming systems are exploring object storage as a primary backend. Kafka was once challenged by WarpStream, a Kafka alternative that leveraged S3 for handling streams of data. WarpStream claimed a No Disk architecture, persisting all data directly to S3 to provide durability and scalability in ways that traditional Kafka architectures—relying on local disks or expensive block storage—could not match. Additionally, brokers across multiple Availability Zones (AZs) could share the same data via S3, avoiding the costly cross-AZ replication traffic typically required for synchronizing WAL logs. WarpStream has since been acquired by Confluent, consolidating its innovations into the broader Kafka ecosystem.

PostgreSQL and the Rise of S3 Storage Engines

One of the most exciting developments is Neon, an open-source alternative to Aurora PostgreSQL, that brings compute-storage separation to PostgreSQL by leveraging S3 as the storage layer. Neon's Page Server converts the database's random writes into log-structured sequential writes stored on S3, transforming PostgreSQL into a serverless database with compute-storage separation, where compute nodes can be restarted, migrated, and recovered from failures extremely quickly.

But Neon is not alone. Another project, OrioleDB(acquired by Supabase), is also developing an experimental S3 storage engine for PostgreSQL, for increasing data safety, and for scaling and changing the architecture of compute instances preserving all data.

Embedded Databases: SQLite and DuckDB Embrace S3

Even embedded databases are not immune to the growing influence of S3. Cloudflare, for instance, has completely replaced the persistent layer of its SQLite storage backend for DO (Durable Objects) with R2, Cloudflare’s S3-compatible object storage service. This move highlights that even lightweight, embedded databases can benefit by using a local disk as a cache on top of durable, cheap object storage, combining fast access with the reliability of S3-like storage.

Meanwhile, MotherDuck is using Differential Storage to store DuckDB data on S3. DuckDB is a high-performance embedded analytical database, often described as SQLite for OLAP workloads. By shifting the storage layer to S3, MotherDuck ensures that DuckDB can take on the role of a central data warehouse, scaling efficiently and handling large datasets without being constrained by local storage limits.

Enterprise Databases: DB2 Integrates with S3

The trend toward S3 is not limited to modern, open-source databases. Even traditional enterprise databases are being rearchitected to take advantage of object storage. A recent paper presented at VLDB 2024 revealed that IBM DB2 Warehouse is undergoing a significant transformation. IBM is replacing DB2’s traditional storage engine with RocksDB, an LSM-based storage engine, and moving data to S3. This change allows DB2 to handle the massive scale of contemporary data workloads, benefiting from object storage not only for cost efficiency but also for improved performance.

Why S3?

So, why are so many databases moving to S3 or S3-compatible storage systems?

Some of the advantages come from S3 itself, which the database can benefit from without requiring any modifications:

  • Scalability: S3 offers virtually unlimited storage capacity, allowing databases to grow without the headaches of managing and provisioning storage manually.
  • Cost Efficiency: S3’s pay-as-you-go pricing model makes it much more affordable than traditional block storage, especially for databases with large datasets or archival needs. It eliminates the need for expensive, pre-provisioned disk space.
  • Durability and Reliability: S3 guarantees 99.999999999% (11 nines) of durability, which means data is incredibly safe from loss. This level of reliability is difficult to achieve with traditional storage systems without significant overhead.
  • High Bandwidth: S3 provides high write bandwidth, ensuring that database I/O operations, such as flushing dirty pages, no longer become bottlenecks. Additionally, S3's high read bandwidth allows databases to load data quickly during startup and enables concurrent scanning of multiple files during queries, reducing latency.
  • Disaster Recovery and Multi-AZ Support: S3’s architecture inherently supports database replication across different Availability Zones (AZs), providing robust disaster recovery options out of the box.

Other reasons are that databases, through modifications, can gain functional and elasticity advantages:

  • Separation of Compute and Storage: By moving data to S3, databases can separate compute resources from storage resources. Compute resources can scale independently, and data (such as partitions or cache hotspots) can be rebalanced between nodes much faster without the need to physically move the data.
  • Shared Data Access: An S3 bucket can be accessed simultaneously by multiple virtual machines. This allows databases to support advanced functionalities such as shared access to data files and the creation of instant, low-cost clones.

The Future: Every Database Will Use S3

As we look ahead, it’s clear that the trend of using S3 for database storage is only accelerating. From OLAP systems like Snowflake and Rockset, to streaming platforms like WarpStream, to relational databases like PostgreSQL (with Neon and OrioleDB), and even embedded databases with DuckDB and SQLite, the entire database ecosystem is moving towards object storage.

The flexibility, scalability, and cost advantages of S3 make it an irresistible choice for modern databases. As more and more projects adopt S3 as their storage backend, it’s only a matter of time before every database—from enterprise systems like DB2 to lightweight embedded databases— will be rearchitected to use S3 or S3-compatible storage solutions.

In the next two to three years, this will no longer be a trend—it will be the norm.

What We Did

WeSQL, to the best of our knowledge, is the first open-source, S3-based database built within the MySQL ecosystem. We replaced InnoDB, the traditional B+ tree-based storage engine, with SmartEngine, an LSM-tree-based storage engine. To overcome S3's write latency, we implemented Raft replication, ensuring that transaction latency is decoupled from S3 write delays. Additionally, we addressed read latency by introducing a multi-tier caching system.

References