http-server-sim 1.1.0.435

http-server-sim

HTTP Server Simulator is a .NET tool that runs a Web API simulating HTTP endpoints, supporting the development and testing of components that use HTTP.

http-server-sim can be called from the shell/command line.

Usage

Installation

Install the latest version from NuGet:

dotnet tool install --global http-server-sim

Once http-server-sim is installed as a global tool, it can run from any folder. For other versions and more information, visit NuGet and dotnet tool install.

Running http-server-sim

Running http-server-sim using default options:

# Start the simulator
http-server-sim

# Send a GET request to the simulator from another terminal
curl --location 'http://localhost:5000/data' -v

Simulator output

Request:
HTTP/1.1 - GET - http://localhost:5000/data
Headers:
  Accept: */*
  Host: localhost:5000
  User-Agent: curl/8.7.1
Body:
[Not present]
End of Request


Response:
Status Code: 200
Headers:
[Not present]
Body:
[Not present]
End of Response

http-server-sim attempts to match a request to a rule. When a rule is found, it responds with the response defined in that rule. If no matching rule is found, it responds with a configurable default response, which has a Status Code 200 and no content.

Running http-server-sim setting the default content:

# Start the simulator setting the default content with a json
http-server-sim --DefaultContentType application/json --DefaultContentValue "{""name"":""Juan""}"

# Send a GET request to the simulator from another terminal
curl --location 'http://localhost:5000/data' -v

Simulator output

...
Response:
Status Code: 200
Headers:
  Content-Type: application/json
Body:
{"name":"Juan"}
End of Response

Another example setting the default response indicating that a resource not was found.

http-server-sim --DefaultContentType text/plain --DefaultContentValue "Resource not found" --DefaultStatusCode 404

Rule file

The simulation of endpoints is based on a rule file. Here’s how it can be set up:

1. Create a rule file defining conditions and a response message.
2. Place the rule file in the appropriate directory.
3. Run the simulator with the rule file.

Example of rule file.

{
  "rules": [
    {
      "name": "customers-post",
      "description": "",
      "conditions": [
        { "field": "Method", "operator": "Equals", "value": "POST" },
        { "field": "Path", "operator": "Contains", "value": "/customers" }
      ],
      "response": {
        "statusCode": 200
      }
    }
  ]
}

# Loading rules from a file in the current directory
http-server-sim --Rules rules.json

# Send a POST request (will be handled by the rule called customers-post):
curl --location 'http://localhost:5000/customers' --header 'Content-Type: application/json' --data '{"id":10,"name":"Juan"}' -v

http-server-sim returns a response with Status Code 200.

Saving request and response messages to files

# Save request and response to the folder messages-history under the current directory
http-server-sim --SaveRequests messages-history --SaveResponses messages-history

• The directory can be a full path, e.g., C:\temp\http-server-sim-messages, or a relative directory under the current directory, e.g., messages-history.
• Messages are saved using a GUID as the name, with the .req extension for request messages and the .res extension for response messages.
• Keep in mind that files are not deleted automatically. If you have a long-running process creating files, the hard drive may eventually run out of space.

http-server-sim CLI options

Rule conditions

When http-server-sim processes a request, it uses rule conditions to match a rule to the request.

Example of conditions:

"conditions": [
  { "field": "Method", "operator": "Equals", "value": "POST" },
  { "field": "Path", "operator": "Contains", "value": "/customers" }
]

A rule with these conditions is applied when:

• The request method is POST, and
• The URL path contains /customers.

There are two types of conditions, Method and Path

1. Method Conditions: These specify the HTTP method (e.g., GET, POST) that the request must match.
2. URL Path Conditions: These specify the URL path that the request must match.

The supported operators are: Equals, StartWith, and Contains

Response messages

When http-server-sim identifies a rule that matches a request, it prepares a response message based on the response section of the rule.

Response properties:

Example of a response defining a message with Status Code 400.

"response": {
  "statusCode": 400
  }

Example of a response defining a message with Status Code 200 and headers Server (with a single value) and Header-1 (with multiple values)

"response": {
  "statusCode": 200,
  "headers": [
    { "key": "Server", "value": ["http-server-sim"] },
    { "key": "Header-1", "value": ["val-1", "val-2"] }
  ]
}

Example of a response with a plain text content.

"response": {
  "contentType": "text/plain",
  "contentValue": "Thank you for the notification",
}

Example of a response using a json file that exists in the current directory.

"response": {
  "contentType": "application/json",
  "contentValue": "person-1.json",
  "contentValueType": "File"
}

Example of a response using an in-line json.

"response": {
  "contentType": "application/json",
  "contentValue": "{\"name\":\"Juan\"}"
}

Example of a response using a json file that exists in the current directory and compressing the content with gzip.

"response": {
  "contentType": "application/json",
  "contentValue": "person-1.json",
  "contentValueType": "File",
  "encoding": "GZip"
}