Transport

Overview

The transport layer abstracts HTTP communication from the session logic. The session builds runCommandJSON payloads and delegates HTTP delivery to a transport implementation. This separation enables testing the entire command pipeline without an MQ server by injecting a mock transport.

MqRestTransport

The transport trait defines a single method for posting JSON payloads:

pub trait MqRestTransport: Send + Sync {
    fn post_json(
        &self,
        url: &str,
        payload: &serde_json::Value,
        headers: &HashMap<String, String>,
        timeout_seconds: Option<f64>,
        verify_tls: bool,
    ) -> Result<TransportResponse, MqRestError>;
}

TransportResponse

A struct containing the HTTP response data:

pub struct TransportResponse {
    pub status_code: u16,
    pub text: String,
    pub headers: HashMap<String, String>,
}

Field	Type	Description
status_code	u16	HTTP response status code
text	String	Response body as text
headers	HashMap<String, String>	Response headers

ReqwestTransport

The default transport implementation using the reqwest blocking client:

pub struct ReqwestTransport { /* ... */ }

impl ReqwestTransport {
    /// Standard HTTPS client
    pub fn new() -> Self;

    /// Client that accepts invalid TLS certificates
    pub fn new_insecure() -> Self;

    /// Client with mutual TLS (client certificate)
    pub fn new_with_cert(cert_path: &str, key_path: Option<&str>) -> Result<Self>;
}

Custom transport

Implement the MqRestTransport trait to provide custom HTTP behavior or for testing:

use mq_rest_admin::{MqRestTransport, TransportResponse, MqRestError};
use std::collections::HashMap;

struct MockTransport;

impl MqRestTransport for MockTransport {
    fn post_json(
        &self,
        _url: &str,
        _payload: &serde_json::Value,
        _headers: &HashMap<String, String>,
        _timeout: Option<f64>,
        _verify: bool,
    ) -> Result<TransportResponse, MqRestError> {
        Ok(TransportResponse {
            status_code: 200,
            text: r#"{"commandResponse": []}"#.into(),
            headers: HashMap::new(),
        })
    }
}

let session = MqRestSession::builder()
    .rest_base_url("https://localhost:9443/ibmmq/rest/v2")
    .qmgr_name("QM1")
    .credentials(Credentials::Basic {
        username: "admin".into(),
        password: "passw0rd".into(),
    })
    .transport(Box::new(MockTransport))
    .build()?;

This pattern makes the entire command pipeline testable without network access.