This tutorial shows you how build a simple Rust application with CockroachDB and the Rust-Postgres driver.
We have tested the Rust-Postgres driver enough to claim beta-level support. If you encounter problems, please open an issue with details to help us make progress toward full support.
Before you begin
- Install CockroachDB.
- Start up a secure or insecure local cluster.
- Choose the instructions that correspond to whether your cluster is secure or insecure:
The --insecure flag used in this tutorial is intended for non-production testing only. To run CockroachDB in production, use a secure cluster instead.
Step 1. Specify the Rust Postgres driver as a dependency
Update your Cargo.toml file to specify a dependency on the Rust Postgres driver, as described in the official documentation.
Additionally, include the OpenSSL bindings and Rust Postgres OpenSSL crates as dependencies.
Step 2. Create the maxroach users and bank database
Start the built-in SQL shell:
$ cockroach sql --certs-dir=certs
In the SQL shell, issue the following statements to create the maxroach user and bank database:
> CREATE USER IF NOT EXISTS maxroach;
> CREATE DATABASE bank;
Give the maxroach user the necessary permissions:
> GRANT ALL ON DATABASE bank TO maxroach;
Exit the SQL shell:
> \q
Step 3. Generate a certificate for the maxroach user
Create a certificate and key for the maxroach user by running the following command. The code samples will run as this user.
$ cockroach cert create-client maxroach --certs-dir=certs --ca-key=my-safe-directory/ca.key
Step 4. Run the Rust code
Now that you have a database and a user, you'll run code to create a table and insert some rows, and then you'll run code to read and update values as an atomic transaction.
Get the code
Clone the example-app-rust-postgres GitHub repo:
$ git clone https://github.com/cockroachdb/example-app-rust-postgres
Basic statements
First, run basic-sample.rs to connect as the maxroach user and execute some basic SQL statements, inserting rows and reading and printing the rows:
404: Not Found
Transaction (with retry logic)
Next, run txn-sample.rs to again connect as the maxroach user but this time execute a batch of statements as an atomic transaction to transfer funds from one account to another, where all included statements are either committed or aborted.
CockroachDB may require the client to retry a transaction in case of read/write contention. CockroachDB provides a generic retry function that runs inside a transaction and retries it as needed. You can copy and paste the retry function from here into your code.
404: Not Found
After running the code, use the built-in SQL client to verify that funds were transferred from one account to another:
$ cockroach sql --certs-dir=certs -e 'SELECT id, balance FROM accounts' --database=bank
+----+---------+
| id | balance |
+----+---------+
| 1 | 900 |
| 2 | 350 |
+----+---------+
(2 rows)
What's next?
Read more about using the Rust Postgres driver.
You might also be interested in the following pages:
- Client Connection Parameters
- Connection Pooling
- Data Replication
- Fault Tolerance & Recovery
- Replication & Rebalancing
- Cross-Cloud Migration
- Automated Operations
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