This page has instructions for connecting to a CockroachDB cluster from your application using various programming languages. Each example shows a connection string for a secure cluster to a bank database. Depending on your cluster's configuration, you may need to edit this connection string.
The connection strings listed on this page set the required authentication options to connect to local clusters. Local clusters use self-signed SSL certificates.
For a reference that lists all of the supported cluster connection parameters, see Connection Parameters.
Before you begin
Do the following:
- Set up a local CockroachDB cluster:
- Install a client driver or ORM framework.
Connect
$ cockroach sql --certs-dir=certs --host=localhost:26257
For more information about how to use the built-in SQL client, see the cockroach sql reference docs.
import (
"database/sql"
"fmt"
"log"
_ "github.com/lib/pq"
)
db, err := sql.Open("postgres",
"postgresql://maxroach@localhost:26257/bank?ssl=true&sslmode=require&sslrootcert=certs/ca.crt&sslkey=certs/client.maxroach.key&sslcert=certs/client.maxroach.crt")
if err != nil {
log.Fatal("error connecting to the database: ", err)
}
defer db.Close()
For complete examples, see:
import java.sql.*;
import javax.sql.DataSource;
PGSimpleDataSource ds = new PGSimpleDataSource();
ds.setServerName("localhost");
ds.setPortNumber(26257);
ds.setDatabaseName("bank");
ds.setUser("maxroach");
ds.setPassword(null);
ds.setSsl(true);
ds.setSslMode("require");
ds.setSslCert("certs/client.maxroach.crt");
ds.setSslKey("certs/client.maxroach.key.pk8");
ds.setReWriteBatchedInserts(true); // add `rewriteBatchedInserts=true` to pg connection string
ds.setApplicationName("BasicExample");
You can pass the --also-generate-pkcs8-key flag to cockroach cert to generate a key in PKCS#8 format, which is the standard key encoding format in Java. For example, if you have the user max:
$ cockroach cert create-client max --certs-dir=certs --ca-key=my-safe-directory/ca.key --also-generate-pkcs8-key
The generated PKCS8 key will be named client.max.key.pk8.
For complete examples, see:
import psycopg2
conn = psycopg2.connect(
database='bank',
user='maxroach',
sslmode='require',
sslrootcert='certs/ca.crt',
sslkey='certs/client.maxroach.key',
sslcert='certs/client.maxroach.crt',
port=26257,
host='localhost'
)
For complete examples, see:
What's next?
You might also be interested in the following pages:
- Connection Pooling
- Connection Parameters
- Manual Deployments
- Orchestrated Deployments
- Start a Local Cluster
- Error Handling and Troubleshooting
- Optimize Query Performance
- Hello World example apps
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