crane

Crane

Crane is a small tool written in Go that enables the ability to send HTML form requests, for example from static websites without a dynamic backend, via email. It can be used for contact forms created on Ghost pages should a user not want to use a third-party service like TypeForm or FormSpree.

Crane is a fork of the MailyGo app by jlelse.

Crane is lean and resource-saving. It can be installed with just one executable file.

Prerequisites

In order to run Crane without any issues you'll need the following:

• Go - v1.4.2 or higher

Installation

Crane can be installed by the following command.

git  clone http://github.com/linuxgoose/crane

Crane can then be started manually with the below command after all environment variables have been set within the bash script.

bash crane-service.sh

Note: If you experience issues with running the bash script, try modifying the script with sudo chmod +x crane-service.sh

Alternatively, you can run the included installation script. This script will capture all of the required environment variables for crane-service.sh and if wanted, create and enable the systemd service.

sudo bash install-crane.sh

If you'd like to run Crane as a service, go to the systemd section for how to set up the service.

Configuration

To run the server, you must set a few environment variables from the list below.

Special form fields

You can find a sample form in the form.html file. Only fields whose name do not start with an underscore (_) will be sent by email. Fields with an underscore serve as control fields for special purposes:

Spam protection

Crane offers the option to use a Honeypot field, which is basically another input, but it's hidden to the user with either a CSS rule or some JavaScript. It is very likely, that your public form will get the attention of some bots some day and then the spam starts. But bots try to fill every possible input field and will also fill the honeypot field. Crane won't send mails of form submissions where a honeypot field is filled. So you should definitely use it.

If a Google Safe Browsing API key is set, submitted URLs will also get checked for threats.

Systemd service creation

Crane can be set up as a systemd service by calling the included crane.sh script. Simply create the systemd service.

sudo nano /lib/systemd/system/crane.service

Paste the below details into the created file after configuring the WorkingDirectory and ExecStart.

[Unit]
Description=Crane email form service
After=network.target

[Service]
Type=simple
User=your_user
WorkingDirectory=/home/your_user/crane
ExecStart=/home/your_user/crane/crane-service.sh

Restart=on-failure
RestartSec=10

StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=appgoservice


[Install]
WantedBy=multi-user.target

Reload the systemd daemon.

 sudo systemctl daemon-reload

Then enable the service.

sudo systemctl enable crane.service

And start it.

sudo systemctl start crane.service

You can check the status of the service with the below to ensure it is actively running. You should see Crane service starting. with no errors following.

sudo systemctl status crane.service

Update Crane

Crane comes with an included update script. To update crane, run the following command in the app's folder.

sudo bash update.sh

License

Crane is licensed under the MIT license, so you can do basically everything with it, but nevertheless, please contribute your improvements to make Crane better for everyone. See the LICENSE file.