CogniCity

Open Source GeoSocial Intelligence Framework

cognicity-rem-server: NodeJS server for CogniCity REM data and web files.

DOI for current stable release v2.0.0:

About

Cognicity-rem-server is the NodeJS server module for the CogniCity framework REM interface, responsible for serving data and web content. For detailed framework documentation see http://cognicity.info

Dependencies

• NodeJS version 4.2.1 or later
• PostgreSQL version 9.2 or later, with PostGIS version 2.0 or later

Node Modules

Please refer to package.json for details of dependencies.

Dev Modules

Please refer to package.json for details of dependencies.

Installation

Download the source code for cognicity-rem-server from github: https://github.com/smart-facility/cognicity-rem-server or view the CogniCity installation documentation at http://cognicity.info. To check it out using git, run git clone --recursive [email protected]:smart-facility/cognicity-rem-server, which will also check out the default web site submodule https://github.com/smart-facility/https://github.com/smart-facility/cognicity-rem-web, which if you fork you can change to your own set of pages (refer to config.public_dir and config.url_prefix in the config.js file). If you have already cloned the repository, and want to check out the submodule, then run

git submodule init
git submodule update

To update the submodule, first cd cognicity-rem-web then git pull origin master, then cd .. to move back to the main cognicity-rem-server directory and then git commit and git push along with any other changes.

Platform-specific notes

To build on OS X we recommend using homebrew to install node, npm, and required node modules as follows:

brew install node
npm install

To build on Windows we recommend installing all dependencies (making sure to use all 32 bit or all 64 bit, depending on your architecture) plus following the instructions (for Windows 7 follow the Windows 7/8 instructions) for node-gyp and then:

• You need to add C:\Program Files\PostgreSQL\9.3\bin (modifying that location if necessary to point to the installed version of PostgreSQL) to path so the build script finds pg_config, and
• You need to create the %APPDATA%\npm folder and run cmd (and hence npm) as administrator. %APPDATA% is usually under C:\Users\your_username\AppData\Remote.
• You may need to specify the version of the build tools installed by adding the argument --msvs_version=2013 to the npm command (substituting the appropriate version) Then you can run npm install.

For the cognicity-rem-web submodule, install the node dependencies in package.json using NPM as follows:

cd cognicity-rem-web
npm install

You can then run grunt if you need to rebuild the build products following changes to its source.

Configuration

Server configuration parameters are stored in a configuration file which is parsed by server.js. See config.js for an example configuration. It is possible to run multiple server instances using different configuration files so long as a unique port is assigned to each instance. Some that you probably want to change:

• config.pg.conString - the database connection string that can include username and password as well as the hostname and database name. If you're deploying to AWS Elastic Beanstalk you will need to configure a property with name DB_NAME and value set to the database name, under Configuration -> Software configuration.
• config.compression - If true, enable Express compression middleware to gzip responses. If deploying standalone then you probably want to set this to true. If deploying behind a reverse proxy+cache like nginx then you will want to leave this config option set to false and enable compressing using the caching server. For Elastic Beanstalk using nginx this is configured automatically using the Elastic Beanstalk config file (note if deploying standalone then this file actually contains only a fragment of an nginx config plus the Elastic Beanstalk headers).
• config.logger.logDirectory - the location of the log file for the server. The default is the current working directory, and the default location + name are set up in the cloud-log-init.config file for easy export of the log file in Elastic Beanstalk.

API

• aggregates.archive.level - The key of the aggregate level ('config.pg.aggregate_levels') to use for archive aggregate response data

Postgres connection

• conString - PostgreSQL connection string see node-postgres module documenation
• reconnectionDelay - Delay between reconnection attempts if postgres connection lost
• reconnectionAttempts - Number of times to attempt to reconnect before dying
• aggregate_levels - Database tables, keys are the label and values are the table name
• infrastructure_tbls - Database tables, keys are the label and values are the table name

Cognicity-rem-server requires a database that conforms to the Cognicity framework schema.

You need to setup the session storage schema - run a command like

psql mydatabase < node_modules/connect-pg-simple/table.sql

See https://github.com/voxpelli/node-connect-pg-simple for more details.

You will also need to import the SQL files from the schema directory.

Authentication

Configure the 'auth.sessionSecret' value - setting this from the environment is a good approach.

Some users are created by default by the 'create-users.sql' script, or you can create more users manually by inserting them into the database (see how to create passwords).

Serving web content

• The config.public_dir parameter is the location of public HTML, CSS, JS web pages to serve.
• By default pages are served at [http://localhost:8081/project-name/], the optional prefix URL can be changed using the config.url_prefix configuration parameter.
• The config.root_redirect parameter defines where a client is redirected to if they request the root path of the server

Data Routes

The following routes exist:

• /data/api/v2/aggregates/live - Live aggregates
• /data/api/v2/rem/flooded - Flooded states
• /data/api/v2/rem/dims - DIMS states

A URL parameter of format=topojson can be appended to any route to receive the response data in topojson format.

Caching

Requests are cached either temporarily (with a timeout set by the config.cache_timeout parameter) or permanently depending on the route.

Run

The server is launched by node.js directly. Note that you must set the SESSION_SECRET environment variable. In production, software on the server should manage launching, health checking and restarting of the process.

$ cd cognicity-rem-server/
$ SESSION_SECRET=my_secret node server.js config.js

Logging

Winston logger writes to [config.instance].log. The log directory is configurable.

Logging parameters

• level - info or debug are most useful here, debug will give you more verbose logging output
• maxFileSize - max size (in bytes) of each log file before a new one is created
• maxFiles - number of log files to retain
• logDirectory - Specify a full path to the log directory. If not specified, the application directory will be used.

Development

Git Hooks

There is a git pre-commit hook which will run the 'npm test' command before your commit and will fail the commit if testing fails.

To use this hook, copy the file from 'git-hooks/pre-commit' to '.git/hooks/pre-commit' in your project folder.

cp git-hooks/pre-commit .git/hooks/

Documentation

To build the JSDoc documentation run the following npm script:

npm run-script build-docs

This will build the HTML API documentation in the folder docs where you can open it with a web browser.

Test Coverage

To build test code coverage documentation, run the following npm script:

npm run-script coverage

This will run istanbul code coverage over the full mocha test harness and produce HTML documentation in the directory coverage where you can open it with a web browser.

testing

To test make sure nothing is running on tcp port 8082. Note this is different to the default port of 8081, to avoid a conflict while testing on the same system the server is running on. Then run:

npm test

Release

The release procedure is as follows:

• Update the CHANGELOG.md file with the newly released version, date, and a high-level overview of changes. Commit the change.
• Update JSDoc documentation if required (see above).
• Create a tag in git from the current head of master. The tag version should be the same as the version specified in the package.json file - this is the release version.
• Update the version in the package.json file and commit the change.
• Further development is now on the updated version number until the release process begins again.
• The deployed version is always in origin/master.

License

This software is released under the GPLv3 License. See License.txt for details.