Add container support to repo

.dockerignore

@@ -0,0 +1,18 @@
+.git
+.gitattributes
+.gitignore
+.dockerignore
+
+debug/
+target/
+
+# Allow configuration files
+!target/debug/*.yaml
+
+.devcontainer/
+.github/
+devops/
+docs/
+tools/
+
+Cargo.lock

.gitignore

@@ -11,3 +11,6 @@ Cargo.lock
 
 # Stops pushes of local vscode files.
 /.vscode/*
+
+# Do not include .env files for Docker.
+*.env

Dockerfile

@@ -0,0 +1,70 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT license.
+# SPDX-License-Identifier: MIT
+
+# syntax=docker/dockerfile:1
+
+# Comments are provided throughout this file to help you get started.
+# If you need more help, visit the Dockerfile reference guide at
+# https://docs.docker.com/engine/reference/builder/
+
+################################################################################
+# Create a stage for building the application.
+
+ARG RUST_VERSION=1.72.1
+ARG APP_NAME=pub-sub-service
+FROM rust:${RUST_VERSION}-slim-bullseye AS build
+ARG APP_NAME
+WORKDIR /app
+
+COPY ./ .
+COPY ./target/debug/*.yaml /app/target/debug/
+
+# Add Build dependencies.
+RUN apt update && apt upgrade -y
+RUN apt install -y cmake protobuf-compiler pkg-config libssl-dev
+
+# Build the application with the 'containerize' feature/
+RUN cargo build --features containerize --release -p pub-sub-service
+
+RUN cp ./target/release/$APP_NAME /app/$APP_NAME
+
+################################################################################
+# Create a new stage for running the application that contains the minimal
+# runtime dependencies for the application. This often uses a different base
+# image from the build stage where the necessary files are copied from the build
+# stage.
+#
+# The example below uses the debian bullseye image as the foundation for running the app.
+# By specifying the "bullseye-slim" tag, it will also use whatever happens to be the
+# most recent version of that tag when you build your Dockerfile. If
+# reproducability is important, consider using a digest
+# (e.g., debian@sha256:ac707220fbd7b67fc19b112cee8170b41a9e97f703f588b2cdbbcdcecdd8af57).
+FROM debian:bullseye-slim AS final
+ARG APP_NAME
+ENV APP_NAME=$APP_NAME
+
+# Create a non-privileged user that the app will run under.
+# See https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#user
+ARG UID=10001
+RUN adduser \
+    --disabled-password \
+    --gecos "" \
+    --home "/nonexistent" \
+    --shell "/sbin/nologin" \
+    --no-create-home \
+    --uid "${UID}" \
+    appuser
+USER appuser
+
+WORKDIR /sdv
+
+# Copy the executable from the "build" stage.
+COPY --from=build /app/$APP_NAME /sdv/
+COPY --from=build /app/target/debug/*.yaml /sdv/target/debug/
+
+# Expose the port that the application listens on.
+EXPOSE 50051
+
+# What the container should run when it is started.
+CMD ./$APP_NAME

README.md

@@ -13,7 +13,8 @@
 <p align="center">
   <a href="#getting-started">Getting Started</a> •
   <a href="#configuration-setup">Configuration Setup</a> •
-  <a href="#running-the-service">Running the Service</a>
+  <a href="#running-the-service">Running the Service</a> •
+  <a href="#running-in-a-container">Running in a Container</a>
 </p>
 
 </br>
@@ -264,6 +265,101 @@ These two methods are used by a publisher to dynamically manage a topic. Please
 see more full featured examples in
 [Running the Simple Samples](./samples/README.md#running-the-simple-samples).
 
+## Running in a Container
+
+See below for instructions on how to run the service in a container. Currently, there is support
+for both Docker and Podman containers. Both variations expect that the other steps have been
+followed above to configure the service and start the MQTT broker.
+
+### Docker
+
+#### Prequisites
+
+Install Docker: [Docker Installation](https://docs.docker.com/engine/install/)
+
+#### Running in Docker
+
+To run the service in a Docker container:
+
+1. Copy the [docker.env](./container/template/docker.env) template from the
+[container](./container/) directory into the project root directory. This file should already be
+set up with out any modification needed.
+
+1. Run the following command in the project root directory to build the docker container from the
+Dockerfile:
+
+    ```shell
+    docker build -t pub_sub_service -f Dockerfile .
+    ```
+
+1. Once the container has been built, start the container in interactive mode with the following
+command in the project root directory:
+
+    ```shell
+    docker run --name pub_sub_service -p 50051:50051 --env-file=docker.env --add-host=host.docker.internal:host-gateway -it --rm pub_sub_service
+    ```
+
+1. To detach from the container, enter:
+
+    ```shell
+    Ctrl-p Ctrl-q
+    ```
+
+1. To stop the container, enter:
+
+    ```shell
+    docker stop pub_sub_service
+    ```
+
+### Podman
+
+#### Prequisites
+
+Install Podman: [Podman Installation](https://podman.io/docs/installation)
+
+#### Running in Podman
+
+To run the service in a Podman container:
+
+1. Copy the [podman.env](./container/template/podman.env) template from the
+[container](./container/) directory into the project root directory. This file should already be
+set up with out any modification needed.
+
+1. Run the following command in the project root directory to build the podman container from the
+Dockerfile:
+
+    ```shell
+    podman build -t pub_sub_service:latest -f Dockerfile .
+    ```
+
+1. Once the container has been built, start the container with the following command in the project
+root directory:
+
+    ```shell
+    podman run -p 50051:50051 --env-file=podman.env --network=slirp4netns:allow_host_loopback=true localhost/pub_sub_service
+    ```
+
+1. To stop the container, find the container with:
+
+    ```shell
+    podman ps
+    ```
+
+    Then run:
+
+    ```shell
+    podman stop <container_name>
+    ```
+
+#### Notes
+
+1. By default, podman does not recognize docker images for dockerfile. To fix this, one can add the
+`docker.io` registry to `/etc/containers/registries.conf` by changing the following field:
+
+    ```conf
+    unqualified-search-registries = ["docker.io"]
+    ```
+
 ## Trademarks
 
 This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft

pub-sub-service/Cargo.toml

@@ -29,4 +29,5 @@ yaml-rust = { workspace = true, optional = true }
 
 [features]
 default = ["yaml"]
-yaml = ["yaml-rust"]
+yaml = ["yaml-rust"]
+containerize = []

pub-sub-service/src/connectors/chariott_connector.rs

@@ -13,6 +13,8 @@
     service_registry::v1::{RegisterRequest, ServiceMetadata},
 };
 
+use crate::load_config::localhost;
+
 type ChariottClient = ServiceRegistryClient<Channel>;
 
 /// Object that contains the necessary information for identifying a specific service.
@@ -39,7 +41,7 @@
     let mut reason = String::new();
 
     while client_opt.is_none() {
-        client_opt = match ServiceRegistryClient::connect(chariott_uri.to_string()).await {
+        client_opt = match ServiceRegistryClient::connect(localhost(chariott_uri)).await {
             Ok(client) => Some(client),
             Err(e) => {
                 let status = Status::from_error(Box::new(e));

pub-sub-service/src/connectors/mosquitto_connector.rs

@@ -14,7 +14,10 @@
 use paho_mqtt::{self as mqtt, MQTT_VERSION_5};
 use std::{process, sync::mpsc};
 
-use crate::pubsub_connector::{self, MonitorMessage, PubSubAction, PubSubConnector};
+use crate::{
+    load_config::localhost,
+    pubsub_connector::{self, MonitorMessage, PubSubAction, PubSubConnector},
+};
 
 /// Mosquitto broker's reserved topic for subscribe related notifications.
 const SUBSCRIBE: &str = "$SYS/broker/log/M/subscribe";
@@ -36,7 +39,7 @@
     /// * `client_id` - Id used when creating a new mqtt client.
     /// * `broker_uri` - The uri of the broker that the client is connecting to.
     fn new(client_id: String, broker_uri: String) -> Self {
-        let host = broker_uri;
+        let host = localhost(&broker_uri);
 
         let create_opts = mqtt::CreateOptionsBuilder::new()
             .server_uri(host)

pub-sub-service/src/load_config.rs

@@ -6,13 +6,39 @@
 
 #![cfg(feature = "yaml")]
 
+use std::env;
+
 use config::{Config, File, FileFormat};
 use log::error;
 use serde_derive::{Deserialize, Serialize};
 
 const CONFIG_FILE: &str = "target/debug/pub_sub_service_settings";
 const CONSTANTS_FILE: &str = "target/debug/constants_settings";
 
+/// If feature 'containerize' is set, will modify a localhost uri to point to container's localhost
+/// DNS alias. Otherwise, returns the uri as a String.
+///
+/// # Arguments
+/// * `uri` - The uri to potentially modify.
+pub fn localhost(uri: &str) -> String {
+    #[cfg(feature = "containerize")]
+    let uri = {
+        // Container env variable names.
+        const HOST_GATEWAY_ENV_VAR: &str = "HOST_GATEWAY";
+        const LOCALHOST_ALIAS_ENV_VAR: &str = "LOCALHOST_ALIAS";
+
+        // Exit the program if container env variables are not set.
+        let host_gateway = env::var(HOST_GATEWAY_ENV_VAR)
+            .unwrap_or_else(|_| panic!("{HOST_GATEWAY_ENV_VAR} is not set"));
+        let localhost_alias = env::var(LOCALHOST_ALIAS_ENV_VAR)
+            .unwrap_or_else(|_| panic!("{LOCALHOST_ALIAS_ENV_VAR} is not set"));
+
+        uri.replace(&localhost_alias, &host_gateway)
+    };
+
+    uri.to_string()
+}
+
 /// Object that contains constants used for establishing connection between services.
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct CommunicationConstants {

pub-sub-service/src/topic_manager.rs

@@ -19,7 +19,10 @@
 };
 use tonic::Request;
 
-use crate::pubsub_connector::{MonitorMessage, PubSubAction};
+use crate::{
+    load_config::localhost,
+    pubsub_connector::{MonitorMessage, PubSubAction},
+};
 
 /// Metadata relevant to a dynamic topic.
 #[derive(Clone, Debug, PartialEq)]
@@ -294,7 +297,8 @@
         }
 
         // Get information from publisher client
-        let mut pub_client = PublisherCallbackClient::connect(action_metadata.uri.clone()).await?;
+        let mut pub_client =
+            PublisherCallbackClient::connect(localhost(&action_metadata.uri)).await?;
 
         let request = Request::new(ManageTopicRequest {
             topic: action_metadata.topic.clone(),