Chapter 6. File-based configuration

AMQ C++ can read the configuration options used to establish connections from a local file named connect.json. This enables you to configure connections in your application at the time of deployment.

The library attempts to read the file when the application calls the container connect method without supplying any connection options.

Note

This feature is currently unavailable on Microsoft Windows.

6.1. File locations

AMQ C++ searches for a file named connect.json at the following locations and in the order shown. It stops at the first match it encounters.

  1. $PWD/connect.json, where $PWD is the current working directory of the client process
  2. $HOME/.config/messaging/connect.json, where $HOME is the current user home directory
  3. /etc/messaging/connect.json

6.2. File format

The connect.json file contains JSON data, with additional support for JavaScript comments.

Many of the options have default values, so a simple example need only provide a few details:

Example: A simple connect.json file

{
    "host": "example.com",
    "user": "alice",
    "password": "secret"
}

SASL and SSL/TLS options are nested under "sasl" and "tls" namespaces:

Example: A connect.json file with SASL and SSL/TLS options

{
    "host": "example.com",
    "user": "ortega",
    "password": "secret",
    "sasl": {
        "mechanisms": ["SCRAM-SHA-1", "SCRAM-SHA-256"]
    },
    "tls": {
        "cert": "/home/ortega/cert.pem",
        "key": "/home/ortega/key.pem"
    }
}

6.3. Configuration options

The option keys containing a dot (.) represent attributes nested inside a namespace.

Table 6.1. Configuration options in connect.json

KeyValue typeDefault valueDescription

scheme

string

"amqps"

"amqp" for cleartext or "amqps" for SSL/TLS

host

string

"localhost"

The hostname or IP address of the remote host

port

string or number

"amqps"

A port number or port literal

user

string

None

The user name for authentication

password

string

None

The password for authentication

sasl.mechanisms

list or string

None (system defaults)

A JSON list of enabled SASL mechanisms. A bare string represents one mechanism. If none are specified, the client uses the default mechanisms provided by the system.

sasl.allow_insecure

boolean

false

Enable mechanisms that send cleartext passwords

tls.cert

string

None

The filename or database ID of the client certificate

tls.key

string

None

The filename or database ID of the private key for the client certificate

tls.ca

string

None

The filename or database ID of the CA certificate

tls.verify

boolean

true

Require a valid server certificate with a matching hostname