https://github.com/lingyielia/app-express-rds-postgis

Create an app able to query location data, with Heroku, Node.js/Express, AWS RDS, PostGIS/PostgreSQL.
https://github.com/lingyielia/app-express-rds-postgis

aws-rds express heroku node-js postgis postgresql

Last synced: about 2 months ago
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Create an app able to query location data, with Heroku, Node.js/Express, AWS RDS, PostGIS/PostgreSQL.

• Host: GitHub
• URL: https://github.com/lingyielia/app-express-rds-postgis
• Owner: lingyielia
• Created: 2018-02-04T00:17:00.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2018-02-22T03:13:43.000Z (almost 7 years ago)
• Last Synced: 2024-10-15T23:53:38.069Z (3 months ago)
• Topics: aws-rds, express, heroku, node-js, postgis, postgresql
• Language: HTML
• Homepage: https://geocrosswalk.herokuapp.com/
• Size: 431 KB
• Stars: 0
• Watchers: 0
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# app-express-rds-postgis

## Overview

This is a simple app that can search which geometries one certain points belongs to.

![demo](figure/demo.png)

To develop this app, the following setups is needed:

- [Amazon RDS](https://aws.amazon.com/rds/)

- [PostgresSQL](https://www.postgresql.org/)

- [PostGIS](https://postgis.net/)

- [Node.js](https://nodejs.org/en/)

- [npm](https://www.npmjs.com/)

- [Express](https://expressjs.com/)

- [EJS](http://ejs.co/)

- [pg-promise](https://vitaly-t.github.io/pg-promise/index.html)

- [bluebird](http://bluebirdjs.com/docs/getting-started.html)

- [Heroku CLI](https://devcenter.heroku.com/articles/heroku-cli)

- [git](https://git-scm.com/)

## Section1. Load Location Data on AWS RDS

Here I will go through setting up an RDS instance with Postgres + PostGIS, and importing the geo-crosswalk data.

I used Amazon RDS, PostgresSQL, PostGIS in this section.

#### 1. Create a PostgreSQL DB Instance named `db_argo` in Amazon RDS

following [this tutorial](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_GettingStarted.CreatingConnecting.PostgreSQL.html#CHAP_GettingStarted.Creating.PostgreSQL).

#### 2. Connect RDS instance with Postgres

    psql --host= --port= --username= --password --dbname=

`DB instance endpoint` and `port` can be found on the RDS instance dashboard.

#### 3. Add geo extension PostGIS.

Type this into the psql prompt:

    CREATE EXTENSION postgis;

    CREATE EXTENSION postgis_topology;

#### 4. Import Data using `shp2pgsql`

Have the shapefile `arcgis_intersections.shp` ready for use. In the directory of this shapefile, type

    shp2pgsql -I -W "latin1" -s 4326 -d -g the_geom arcgis_intersections.shp db_argo |psql -U  -p  -h  db_argo

#### 5. Test

Query the geometry of the first entry

    SELECT ST_AsGeoJson(the_geom) from db_argo LIMIT 1;

Query first three entries

    SELECT * from db_argo LIMIT 3;

![test](figure/test.png)    

Query where a certain point falls into

    SELECT *

    FROM db_argo

    WHERE ST_Contains (db_argo.the_geom, ST_GeomFromText('Point(-118.159953387143 33.8719625444075)', 4326))=TRUE;

![test](figure/point.png)

## Section2. Develop the website on AWS Cloud9

I used Node.js, npm, Express, EJS, pg-promise, bluebird in this section. I also used AWS Cloud9 for developing, which has the developing environment ready for Node.js, so I don't need to spend time setting up local environment (debugging all kinds of unexpected conflicts). But this is not necessary. You can use whatever IDE you like.

__Notice:__ Before moving to the next step, make sure you have a `package.json` file in your folder, which is necessary when deploying on the Heroku. If not, type the following to create one

    npm init

npm is a manager of javascript libraries. Express is employed to construct the framework, and EJS makes it possible to generate HTML markup with plain JavaScript.

pg-promise and bluebird are employed for easy querying the PostgreSQL Database on AWS RDS.

__Notice__: When installing these libraries above, make sure having `--save` in the code, so that this library can be automatically recorded in the `package.json`. Like this

    npm install express --save

Before the final deployment, check the content of `package.json`. It should have all library names and versions in it. Meanwhile, make sure there is one line denoting the initial start of your project. In my case, I need to call `node app.js` to start the server. This is __important__ as it will tell the Heroku to find my starting point.

![start](figure/start.png)

## Section3. Deploy the project on Heroku

I used Heroku CLI, git in this section.

#### 1. Heroku basic setup

Register a free account on [Heroku](https://www.heroku.com/) and download the Heroku CLI. Type

    heroku login

Check the versions of node, npm, git in your local environment, make sure they are existing and are of recent versions.

    node -v

    npm -v

    git --version

#### 2. Deploy using git

Locate to the path where you put your files developed in the Section2. Initialize a local git repo and commit your files

    git init

    git add 

    git commit -m "first"

#### 3. Magic happens in Heroku

Type the following two lines

    heroku create

    git push heroku master

Now, the app is officially deployed!