Install a registry server

How to install and update your own Tatin registry server

Download

Download the Tatin Server ZIP from the Releases page and unzip it into the installation folder.

Configure

Local variable

Before the first section declaration ([CONFIG]), local variable home is assigned '<INIFILE>/'.

References to {home} get replaced by its value.

Edit the configuration file Server/server.ini.

Plodder INI files have unusual features.¹ The most important are

• typed data: put text in quotes; anything else is numeric
• you can define local variables

When the Tatin Server loads the INI file, it replaces <INIFILE> with the fully qualified path of the INI file.

See aplteam/Plodder for INI file settings. Here are those you are likely to change for your Tatin server.

APP

Connect Plodder to the Tatin logic: see Plodder documentation.

The On* handlers are Tatin-specific entry points. You might want to add something to OnHouseKeeping, or add a handler OnHeader, but that is pretty unusual.

CERTIFICATES

A certificate is required to use HTTPS. (Recommended for public-facing servers.)

On the Web, use a reverse proxy to hide Tatin behind a Web server

If you use a reverse proxy, you might not need encryption (HTTPS) and certificates.

CONFIG

AppName	Name used by Tatin for logging into the Windows Event Log. The setting has no meaning on non-Windows platforms, and is ignored if [LOGGING]WindowsEventLog is 0.
Base BaseTagPort	(Ignored from version 0.104.0.)
Caption	H1 element for HTML pages.
DeletePackages	Deleting packages is: 0 – not allowed; 1 – allowed; 2 – allowed only for betas. The Principal Registry will not delete anything. A build can always be reproduced.
Registry	Path to the the registry.
ReloadWS	Flag: whether Tatin frequently checks for and reloads new versions of workspace Server.dws, meaning it will (kind of) restart itself. Not recommended in production, but can be helpful in development.
Secure	Flag: whether certificates are used (HTTPS) or not (HTTP).
Title	Browser window or tab title for HTML pages.

EMAIL

Your Tatin server can send alerts by email.

LICENSE

Names of the licences (and URLs to their definitions) the server accepts.

The INI section is optional. if absent, the website shows no Licensing menu item, and the server accepts any license, including packages that lack a license property.

By convention, BuildPackage copies any file LICENSE in the root of the project to the root of a package. This convention is independent of the INI file.

The text on the server web page is defined in Assets/snippets/Licensing.md.

LOGGING

Control how much information Tatin logs.

Log	Flag: log at high level. Keep set.
LogHTTP LogConga LogRumba	Flags: log at low level.
WindowsEventLog	Flag: write to the Windows Event Log. (Recommended, but Windows only.)

IP addresses are not logged at the high level. They are logged at the low level, which can be useful for development, but in some jurisdictions may not be legal on internet servers.

MSG

Inject a message into every HTML page; for example to announce downtime due to maintenance.

Text	Unless empty, inject as <div><p>{text}</p></div>
CSS	Unless empty, inject into the Text <div> as style="{css}"

Start a local Tatin server

Start an instance of Dyalog with ample memory, and load the workspace Server.dws. The Latent Expression starts the server.

Most foreseeable errors (bugs in Tatin etc.) are trapped and return a 500 (Internal Server Error) response but do not stop the server. However, errors such as an aplcore or a WS FULL could bring the server down.

On Windows

Running the server as a Windows Service gives you the best performance, but running it in a Docker container is still surprisingly fast, given that it runs a (very basic) version of Linux in a virtual machine.

To have the server restarted automatically after a failure, run it

• on Windows as a Windows Service
• on Linux and Windows in a Docker container

To run the Tatin server as a Windows Service, use the workspace InstallAsWindowsService.dws, which installs Tatin as a Windows service. (Requires admin rights.)

Configure Docker

To run Tatin in a Docker container, first adjust the Docker configuration to your environment and needs.

Dockerfile

This file defines what Docker should put into the container.

In particular, it must point to the desired version of Dyalog APL, so check the variables DYALOG_RELEASE, DYALOG_VERSION and DYALOG_DEBFILE. Copy the appropriate version of Dyalog APL into the folder that holds the Docker-related files.

FROM	Name of the desired Linux distribution and the version number.
MAINTAINER	Your Docker username and email address.
WORKDIR	Do not change this!
DYALOG_SERIAL	Do not change this! The licence number is explicitly reserved for Tatin servers.

entrypoint

Environment variables TRACE_ON_ERROR, SINGLETRACE and CLASSICMODE might need adjusting to your taste.

CreateTatinDockerContainer.sh

Change the source to the folder that hosts the Tatin server data.

Ports 80 and 443 respectively are the standard ports for HTTP and HTTPS.

The server listens to port 9090, which the default configuration exposes. It is unsafe to remap this to ports 80 or 443 except on an isolated machine: run a public Tatin server on the Web behind a webserver such as Apache or Nginx.

The second port exposed in the script is for connecting to the interpreter with Ride, if permitted by the INI file.

Docker workflow

Call:

1. ./BuildImage.sh to create the image
2. ./CreateTatinDockerContainer.sh to create the container from the image
3. start-tatin.sh to start the container; the script ensures the container is restarted after a crash or auto-started after a reboot

Testing and debugging

For testing and debugging you might want to change in server.ini the settings in the LOGFILE section, and these flags in CONFIG:

DisplayRequests	Make Rumba display every request.
LogHTTPToSession	Print HTTP requests to the session.
TestFlag	Accept extra commands as REST requests.
ReloadWS	Reload the server workspace if you detect a new one.

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1. See aplteam/IniFiles. ↩