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ajcwebdev
ajcwebdev

Posted on • Edited on • Originally published at ajcwebdev.com

A First Look at PostGraphile with Railway

#postgraphile #postgres #graphql #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
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railway version 0.2.40
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Login with railway login

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

railway login
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Initialize project with railway init

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

railway init
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Provision PostgreSQL with railway add

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

railway add
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Connect to database 

railway connect postgresql
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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=#
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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!');
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01-railway-seed-data

List tables in database 

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

\d post
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 Table "public.post" Column | Type | Collation | Nullable | Default --------+------+-----------+----------+--------- title | text | | | body | text | | |
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Quit psql 

\q
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Copy database connection string to clipboard 

echo `railway variables get DATABASE_URL` | pbcopy
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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
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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
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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 } } } }"}'
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{ "data":{ "query":{ "allPosts":{ "totalCount":2, "nodes":[ { "body":"Wooooooo", "title":"This is a blog post" }, { "body":"Even better than the other!", "title":"Another blog post" } ] } } } }
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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
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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
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Send the same query with your API tool of choice.

03-all-posts-query

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