Add README file

Signed-off-by: Ygal Blum <[email protected]>

README.md

@@ -0,0 +1,92 @@
+# Slack Server Mock
+Slack server mock is intended to be used for sub-system testing of Slack applications.
+
+## Running the Server
+
+### Required files
+
+#### settings.yaml
+Create a settings.yaml file based on the [sample file](./settings.yaml).
+
+#### Channels file
+If you wish to return a list of channels, create a JSON file with an array of channel objects.
+At minimum, each entry must have a name and an ID.
+
+In the `settings.yaml` file, set `slack_server.channels_path` to the location of the file.
+
+### Using Poetry
+
+#### Prerequisites
+Install [poetry](https://python-poetry.org/docs/)
+
+#### Installation
+- Download the code and change to the downloaded directory:
+  ```bash
+  git clone https://github.com/ygalblum/slack-server-mock.git
+  cd slack-server-mock
+  ```
+- Install all the requirements using poetry:
+  ```bash
+  poetry install --no-root
+  ```
+- Run the application:
+  ```bash
+  poetry run python -m slack_server_mock
+  ```
+
+### Using a Podman/Docker
+
+The server is published in a container image on [quay](https://quay.io/repository/yblum/slack_server_mock).
+
+#### Running the latest version
+```bash
+podman run --rm -it -d --name slack_server_mock --publish 3001:3001 --publish 8080:8080 --publish 8888:8888 --volume ${PWD}/settings.yaml:/app/settings.yaml:z quay.io/yblum/slack_server_mock:latest
+```
+
+#### Channels file
+If you are using a channels file, make sure to mount it into the container as well.
+
+## Configure your Slack application
+In order to make your Slack application connect with the mock server you need to override its `base_url`.
+
+### Socket mode
+Instead of:
+```python
+handler = SocketModeHandler(
+    App(token=BOT_TOKEN),
+    APP_TOKEN
+)
+```
+
+Use:
+```python
+handler = SocketModeHandler(
+    app=App(
+        client=WebClient(
+            token=BOT_TOKEN,
+            base_url="http://localhost:8888"
+        )
+    ),
+    app_token=settings.slackbot.app_token
+)
+```
+
+## Interacting with the application
+The mock server provides an endpoint to send a message to the application,
+wait for the application response and return the accumulated ephemeral messages (if sent) and the response.
+
+### Message payload
+The request payload is a JSON with the key `message` whose value is a string
+
+### Response payload
+The response payload is a JSON with two keys:
+
+- `ephemeral`: List of strings. All accumulated ephemeral message
+- `response`: string. The application's response
+
+### Example
+Send a message using `curl` and see the response:
+```bash
+$ curl http://localhost:8080/message -d'{"message": "hello"}'
+{"answer": "Hello to you too", "ephemeral": ["I'll be right with you"]}
+```