Lifailon / bash-api-server

REST API (HTTP) server based on Apache and backend Bash via cgi module for remote managment Linux using curl or Invoke-WebRequest in Windows.

Bash API Server

REST API server based on Apache and backend Bash via cgi module for remote managment Linux 🐧 using curl or Invoke-WebRequest in Windows.

Implemented Linux service management via systemd (with systemctl commands) using basic authorization.

🚀 Install

Install an Apache server and jqlang for json processing (in the example for Ubuntu/Debian):

apt install apache2 jq

Build

The following described customization steps can be performed using the build script.

💡 Sudo privileges required

1. Configure port 8443 (or use any other by specifying it in VirtualHost):

cat /etc/apache2/ports.conf | sed -r "s/^Listen.+/Listen 8443/" > /etc/apache2/ports.conf

2. Activate the HTTP Basic Authentication module and add a user (in the example rest and password api):

a2enmod auth_basic
htpasswd -b -c /etc/apache2/.htpasswd rest api

3. Create a file at the path /var/www/api/api.sh and copy the contents of the api.sh script:

mkdir /var/www/api && touch /var/www/api/api.sh && chmod +x /var/www/api/api.sh
curl -s "https://raw.githubusercontent.com/Lifailon/bash-api-server/rsa/www/api/api.sh" > /var/www/api/api.sh

4. Configure a VirtualHost (/etc/apache2/sites-available/api.conf) this way:

<VirtualHost *:8443>
    ScriptAlias /api /var/www/api/api.sh
    <Directory "/var/www/api">
        Options +ExecCGI
        AddHandler cgi-script .sh
        AllowOverride None
        Require all granted
    </Directory>
    <Location "/api">
        AuthType Basic
        AuthName "Restricted Area"
        AuthUserFile /etc/apache2/.htpasswd
        Require valid-user
        SetHandler cgi-script
        Options +ExecCGI
    </Location>
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

5. Activate the module for working cgi-scripts, activate the created VirtualHost and start the server:

a2enmod cgi
a2ensite api.confs
systemctl restart apache2

6. In order for the Apache server to be able to manage services, the www-data user must be granted the appropriate sudo permissions:

echo "www-data ALL=(ALL) NOPASSWD: /bin/systemctl start *, /bin/systemctl stop *, /bin/systemctl restart *" >> /etc/sudoers

📑 Examples

Get the status of the service specified in the header (the example, cron):

curl -s -X GET http://192.168.3.101:8443/api/service/cron -u rest:api

{
  "unit": "cron.service",
  "load": "loaded",
  "active": "active",
  "sub": "running",
  "description": "Regular background program processing daemon",
  "uptime": "5h 1min",
  "startup": "enabled"
}

Stop the service:

curl -s -X POST http://192.168.3.101:8443/api/service/cron -u rest:api -H "Status: stop"

{
  "unit": "cron.service",
  "load": "loaded",
  "active": "inactive",
  "sub": "dead",
  "description": "Regular background program processing daemon",
  "uptime": "108ms",
  "startup": "enabled"
}

Start the service:

curl -s -X POST http://192.168.3.101:8443/api/service/cron -u rest:api -H "Status: start"

{
  "unit": "cron.service",
  "load": "loaded",
  "active": "active",
  "sub": "running",
  "description": "Regular background program processing daemon",
  "uptime": "104ms",
  "startup": "enabled"
}

PowerShell (output in default object format):

$user = "rest"
$pass = "api"
$EncodingCred = [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes("${user}:${pass}"))
$Headers = @{"Authorization" = "Basic ${EncodingCred}"}
Invoke-RestMethod -Headers $Headers -Uri http://192.168.3.101:8443/api/service/cron

unit        : cron.service
load        : loaded
active      : active
sub         : running
description : Regular background program processing daemon
uptime      : 41min
startup     : enabled

List of services in HTML table format when accessed through a Web browser Chrome: