Build a Ruby App with CockroachDB and Active Record

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This tutorial shows you how build a simple Ruby application with CockroachDB and Active Record. CockroachDB provides an Active Record adapter for CockroachDB as a RubyGem.

Tip:

For a more realistic use of Active Record with CockroachDB in a Rails app, see our examples-orms repository.

Step 1. Start CockroachDB

Choose your installation method

You can create a CockroachDB serverless cluster using either the CockroachDB Cloud Console, a web-based graphical user interface (GUI) tool, or ccloud, a command-line interface (CLI) tool.

Create a free cluster

  1. If you haven't already, sign up for a CockroachDB Cloud account.
  2. Log in to your CockroachDB Cloud account.
  3. On the Clusters page, click Create Cluster.
  4. On the Create your cluster page, select Serverless.

    Unless you change your monthly budget, this cluster will be free forever.

  5. Click Create cluster.

    Your cluster will be created in a few seconds and the Create SQL user dialog will display.

Create a SQL user

The Create SQL user dialog allows you to create a new SQL user and password.

  1. Enter a username in the SQL user field or use the one provided by default.
  2. Click Generate & save password.
  3. Copy the generated password and save it in a secure location.
  4. Click Next.

    Currently, all new users are created with full privileges. For more information and to change the default settings, see Granting privileges and Using roles.

Get the root certificate

The Connect to cluster dialog shows information about how to connect to your cluster.

  1. Select General connection string from the Select option dropdown.
  2. Open a new terminal on your local machine, and run the CA Cert download command provided in the Download CA Cert section. The client driver used in this tutorial requires this certificate to connect to CockroachDB Cloud.

Get the connection string

Open the General connection string section, then copy the connection string provided and save it in a secure location.

Note:

The connection string is pre-populated with your username, password, cluster name, and other details. Your password, in particular, will be provided only once. Save it in a secure place (Cockroach Labs recommends a password manager) to connect to your cluster in the future. If you forget your password, you can reset it by going to the SQL Users page.

Follow these steps to create a CockroachDB serverless cluster using the ccloud CLI tool.

Note:

The ccloud CLI tool is in Preview.

Install ccloud

Choose your OS:

You can install ccloud using either Homebrew or by downloading the binary.

Use Homebrew

  1. Install Homebrew.
  2. Install using the ccloud tap:

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    brew install cockroachdb/tap/ccloud
    

Download the binary

In a terminal, enter the following command to download and extract the ccloud binary and add it to your PATH:

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curl https://binaries.cockroachdb.com/ccloud/ccloud_darwin-amd64_0.2.5.tar.gz | tar -xJ && cp -i ccloud /usr/local/bin/

Use the ARM 64 binary if you have an M1 Mac:

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curl https://binaries.cockroachdb.com/ccloud/ccloud_darwin-arm64_0.2.5.tar.gz | tar -xJ && cp -i ccloud /usr/local/bin/

In a terminal, enter the following command to download and extract the ccloud binary and add it to your PATH:

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curl https://binaries.cockroachdb.com/ccloud/ccloud_linux-amd64_0.2.5.tar.gz | tar -xz && cp -i ccloud /usr/local/bin/

In a PowerShell window, enter the following command to download and extract the ccloud binary and add it to your PATH:

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$ErrorActionPreference = "Stop"; [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $ProgressPreference = 'SilentlyContinue'; $null = New-Item -Type Directory -Force $env:appdata/ccloud; Invoke-WebRequest -Uri https://binaries.cockroachdb.com/ccloud/ccloud_windows-amd64_0.2.5.zip -OutFile ccloud.zip; Expand-Archive -Force -Path ccloud.zip; Copy-Item -Force ccloud/ccloud.exe -Destination $env:appdata/ccloud; $Env:PATH += ";$env:appdata/ccloud"; # We recommend adding ";$env:appdata/ccloud" to the Path variable for your system environment. See https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_environment_variables#saving-changes-to-environment-variables for more information.

Run ccloud quickstart to create a new cluster, create a SQL user, and retrieve the connection string.

The easiest way of getting started with CockroachDB Cloud is to use ccloud quickstart. The ccloud quickstart command guides you through logging in to CockroachDB Cloud, creating a new CockroachDB serverless with a $0 spend limit, and connecting to the new cluster. Run ccloud quickstart and follow the instructions:

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ccloud quickstart

The ccloud quickstart command will open a browser window to log you in to CockroachDB Cloud. If you are new to CockroachDB Cloud, you can register using one of the single sign-on (SSO) options, or create a new account using an email address.

The ccloud quickstart command will prompt you for the cluster name, cloud provider, and cloud provider region, then ask if you want to connect to the cluster. Each prompt has default values that you can select, or change if you want a different option.

Select General connection string, then copy the connection string displayed and save it in a secure location. The connection string is the line starting postgresql://.

? How would you like to connect? General connection string
Retrieving cluster info: succeeded
 Downloading cluster cert to /Users/maxroach/.postgresql/root.crt: succeeded
postgresql://maxroach:ThisIsNotAGoodPassword@free-tier4.aws-us-west-2.cockroachlabs.cloud:26257/defaultdb?options=--cluster%3Ddim-dog-147&sslmode=verify-full&sslrootcert=%2FUsers%2Fmaxroach%2F.postgresql%2Froot.crt

  1. If you haven't already, download the CockroachDB binary.
  2. Run the cockroach start-single-node command:

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    $ cockroach start-single-node --advertise-addr 'localhost' --insecure
    

    This starts an insecure, single-node cluster.

  3. Take note of the following connection information in the SQL shell welcome text:

    CockroachDB node starting at 2021-08-30 17:25:30.06524 +0000 UTC (took 4.3s)
    build:               CCL v21.1.6 @ 2021/07/20 15:33:43 (go1.15.11)
    webui:               http://localhost:8080
    sql:                 postgresql://root@localhost:26257?sslmode=disable
    

    You'll use the sql connection string to connect to the cluster later in this tutorial.

Warning:

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 2. Get the code

Clone the code's GitHub repository.

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git clone https://github.com/cockroachlabs/example-app-ruby-activerecord

Step 3. Configure the dependencies

  1. Install libpq for your platform.

    For example, to install libpq on macOS with Homebrew, run the following command:

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    brew install libpq
    
  2. Configure bundle to use libpq.

    For example, if you installed libpq on macOS with Homebrew, run the following command from the example-app-ruby-activerecord directory:

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    bundle config --local build.pg --with-opt-dir="{libpq-path}"
    

    Where {libpq-path} is the full path to the libpq installation on your machine (e.g., /usr/local/opt/libpq).

  3. Install the dependencies:

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    bundle install
    

Step 4. Run the code

  1. Set the DATABASE_URL environment variable to the connection string to your CockroachDB Cloud cluster:

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    $ export DATABASE_URL="postgresql://root@localhost:26257?sslmode=disable"
    
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    $ export DATABASE_URL="{connection-string}"
    

    Where {connection-string} is the connection string you copied earlier.

    The app uses the connection string saved to the DATABASE_URL environment variable to connect to your cluster and execute the code.

  2. Run the code to create a table and insert some rows:

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    ruby main.rb
    

    The output should be similar to the following:

    -- create_table(:accounts, {:force=>true, :id=>:integer})
       -> 0.1998s
    account: 1 balance: 1000
    account: 2 balance: 250
    

What's next?

Read more about using Active Record, or check out a more realistic implementation of Active Record with CockroachDB in a Rails app in our examples-orms repository.

You might also be interested in the following pages:


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