mailerq/httpcaller repository overview

⁠Docker images for MailerQ HttpCaller

This repository contains the built versions for MailerQ HttpCaller. Dockerfile is available at GitHub⁠.

⁠Setup

The MailerQ HttpCaller is typically configured using environment variables. While you can provide a custom configuration file, using environment variables is the recommended and most common approach for Docker deployments.

The default configuration file is stored at /etc/copernica/httpcaller.txt inside the container. All settings from this file can be overridden using environment variables.

⁠Configuration Options

The following options can be configured for the MailerQ HttpCaller. These settings control how the HttpCaller reads messages from a RabbitMQ message queue, makes HTTP requests, and then publishes the results back to RabbitMQ. Environment variables are the preferred method for configuring these options.

• HTTPCALLER_RABBITMQ_ADDRESS: The RabbitMQ address in amqp://user:password@hostname/vhost format. This is a required setting.
• HTTPCALLER_RABBITMQ_API: The REST API endpoint of the RabbitMQ server in http://user:password@hostname:port format.
• HTTPCALLER_RABBITMQ_QUEUE: The name of the queue from which messages are read. This is a required setting.
• HTTPCALLER_RABBITMQ_EXCHANGE: The exchange to which the results of the HTTP calls are published. This is a required setting.
• HTTPCALLER_RABBITMQ_OVERFLOW_QUEUES: Whether to use overflow queues, can be "true" or "false".
• HTTPCALLER_RABBITMQ_QUEUE_TYPE: The type of queues to use for overflow queues ("classic" or "quorum").
• HTTPCALLER_RABBITMQ_ROUTINGKEY_DELAYED: The name of the routing key for delayed messages.
• HTTPCALLER_RABBITMQ_ROUTINGKEY_FAILURE: The routing key for failures.
• HTTPCALLER_RABBITMQ_ROUTINGKEY_SUCCESS: The routing key for successes.

See all supported options in documentation⁠

⁠Overriding Configuration with Environment Variables

Any setting from the /etc/copernica/httpcaller.txt configuration file can be overridden using environment variables. To create the environment variable name:

1. Convert the configuration setting name to uppercase.
2. Replace dashes (-) with underscores (_).

For example, the rabbitmq-address setting becomes the HTTPCALLER_RABBITMQ_ADDRESS environment variable.

⁠Alternative Configuration Methods

Besides environment variables, you can also configure HttpCaller using the following methods:

• Configuration File: Mount a custom configuration file to /etc/copernica/httpcaller.txt.
• Command Line Arguments: Pass settings directly as command-line arguments to the docker run command. For example: docker run mailerq/httpcaller --rabbitmq-address amqp://...

⁠Example

# Build the Docker image
docker build ./MailerQ-HttpCaller/ -t mailerq/httpcaller

# Example using environment variables
docker run -d \
  -e HTTPCALLER_RABBITMQ_ADDRESS="amqp://user:password@host:port/vhost" \
  -e HTTPCALLER_RABBITMQ_QUEUE="my_queue" \
  -e HTTPCALLER_RABBITMQ_EXCHANGE="my_exchange" \
  mailerq/httpcaller

# Example using a config file
docker run -v /path/to/minimal-config.txt:/etc/copernica/httpcaller.txt mailerq/httpcaller

# Example using command line arguments
docker run mailerq/httpcaller --rabbitmq-address amqp://user:password@host:port/vhost --rabbitmq-queue my_queue --rabbitmq-exchange my_exchange