A First Look at PostGraphile with Railway

ajcwebdev

ajcwebdev

Posted on July 17, 2021

A First Look at PostGraphile with Railway

Outline

All of this project's code can be found in the First Look monorepo on my GitHub.

Introduction

PostGraphile builds a GraphQL API from a PostgreSQL schema that automatically detects tables, columns, indexes, relationships, views, types, functions, and comments. It combines PostgreSQL's role-based grant system and row-level security policies with Graphile Engine's GraphQL look-ahead and plugin expansion technologies.

Provision a PostgreSQL database with Railway

There are two ways to setup a PostgreSQL database with Railway, through the dashboard or through the CLI.

Railway Dashboard

Click dev.new and choose "Provision PostgreSQL" After the database is setup click "PostgreSQL" on the left and then choose "Connect". Copy and paste the PostgreSQL client command.

Railway CLI

First you need to install the Railway CLI.

Check Railway CLI version

railway version
Enter fullscreen mode Exit fullscreen mode
railway version 0.2.40
Enter fullscreen mode Exit fullscreen mode

Login with railway login

If you do not have a Railway account you will be prompted to create one.

railway login
Enter fullscreen mode Exit fullscreen mode

Initialize project with railway init

Run the following command, select “Empty Project,” and give your project a name.

railway init
Enter fullscreen mode Exit fullscreen mode

Provision PostgreSQL with railway add

Run the following command and select PostgreSQL to add a plugin to your Railway project.

railway add
Enter fullscreen mode Exit fullscreen mode

Connect to database

railway connect postgresql
Enter fullscreen mode Exit fullscreen mode
psql (13.3, server 13.2)
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, bits: 256, compression: off)
Type "help" for help.

railway=# 
Enter fullscreen mode Exit fullscreen mode

Seed database

Run the following SQL commands to create a test table with seed data.

CREATE TABLE Post (title text, body text);
INSERT INTO Post VALUES ('This is a blog post', 'Wooooooo');
INSERT INTO Post VALUES ('Another blog post', 'Even better than the other!');
Enter fullscreen mode Exit fullscreen mode

01-railway-seed-data

List tables in database

\d
Enter fullscreen mode Exit fullscreen mode
        List of relations
 Schema | Name | Type  |  Owner   
--------+------+-------+----------
 public | post | table | postgres
(1 row)
Enter fullscreen mode Exit fullscreen mode

Describe table

\d post
Enter fullscreen mode Exit fullscreen mode
              Table "public.post"
 Column | Type | Collation | Nullable | Default 
--------+------+-----------+----------+---------
 title  | text |           |          | 
 body   | text |           |          | 
Enter fullscreen mode Exit fullscreen mode

Quit psql

\q
Enter fullscreen mode Exit fullscreen mode

Copy database connection string to clipboard

echo `railway variables get DATABASE_URL` | pbcopy
Enter fullscreen mode Exit fullscreen mode

Introspect Database with PostGraphile

It is easy to install PostGraphile with npm, although the PostGraphile documentation does not recommend installing PostGraphile globally if you want to use plugins.

npm install -g postgraphile
Enter fullscreen mode Exit fullscreen mode

If you do not globally install you will need to add npx the beginning of all postgraphile commands in this tutorial.

Introspect Railway Database

railway run postgraphile --watch --enhance-graphiql --dynamic-json --port 5001
Enter fullscreen mode Exit fullscreen mode

Open localhost:5001/graphiql and send the following query.

02-postgraphile-graphiql

Test the endpoint

curl \
  --request POST \
    --url "http://localhost:5001/graphql" \
    --header "Content-Type: application/json" \
    --data '{"query":"{ query { allPosts { totalCount nodes { body title } } } }"}'
Enter fullscreen mode Exit fullscreen mode
{
  "data":{
    "query":{
      "allPosts":{
        "totalCount":2,
        "nodes":[
          {
            "body":"Wooooooo",
            "title":"This is a blog post"
          },
          {
            "body":"Even better than the other!",
            "title":"Another blog post"
          }
        ]
      }
    }
  }
}
Enter fullscreen mode Exit fullscreen mode

Connect to endpoint with ngrok

ngrok provides an instant, secure URL to your localhost server through any NAT or firewall where you can introspect all HTTP traffic running over your tunnels.

./ngrok http 5001
Enter fullscreen mode Exit fullscreen mode
Session Status                online
Account                       Anthony Campolo (Plan: Free)
Version                       2.3.40
Region                        United States (us)
Web Interface                 http://127.0.0.1:4040
Forwarding                    http://363ef1ef5cf3.ngrok.io -> http://localhost:5001
Forwarding                    https://363ef1ef5cf3.ngrok.io -> http://localhost:5001

Connections                   ttl     opn     rt1     rt5     p50     p90
                              2       0       0.00    0.00    5.11    5.21
Enter fullscreen mode Exit fullscreen mode

Send the same query with your API tool of choice.

03-all-posts-query

💖 💪 🙅 🚩
ajcwebdev
ajcwebdev

Posted on July 17, 2021

Join Our Newsletter. No Spam, Only the good stuff.

Sign up to receive the latest update from our blog.

Related

A First Look at PostGraphile with Railway