Author Archives: bullgare

mountebank for mocking and stubbing http services (rest+graphql+grpc)

http://www.mbtest.org/docs/api/stubs can be used to stub http(s)/tcp/smtp protocols. And has community plugins for grpc, graphql, websockets. You can configure it with imposters.ejs like below:

{
  "port": 80,
  "protocol": "http",
  "defaultResponse": {
    "statusCode": 404,
    "headers": {}
  },
  "stubs": [
    <% include stubs/service1.json %>,
    <% include stubs/service2.json %>,
    <% include stubs/service3.json %>
  ]
}

{

"port": 80,

"protocol": "http",

"defaultResponse": {

"statusCode": 404,

"headers": {}

"stubs": [

<% include stubs/service1.json %>,

<% include stubs/service2.json %>,

<% include stubs/service3.json %>

]

}

docker-compose.yml

version: "3.5"

services:
  mountebank:
    container_name: mountebank
    image: jkris/mountebank:latest
    volumes:
      - ./:/mountebank
    ports:
      - "15050:80"
    command: --configfile /mountebank/imposters.ejs --allowInjection

version: "3.5"

services:

mountebank:

container_name: mountebank

image: jkris/mountebank:latest

volumes:

- ./:/mountebank

ports:

- "15050:80"

command: --configfile /mountebank/imposters.ejs --allowInjection

HTTP Toolkit — another alternative to Charles Proxy for http calls interception

https://httptoolkit.com/ It has a free version which does something similar to Charles Proxy, so you can hack into the middle of any request/response according to the rules specified.

YouType to show flag icon for current locale on MacOS

It has reacher functionality, but I use it only to show a flag for my current locale in a tray. https://github.com/freefelt/YouType

Add new video sticker pack to telegram

If you have an animated gif-file, you can convert it to webm video respecting rules described in the docs (https://core.telegram.org/stickers#video-stickers-and-emoji): For stickers, one side must be exactly 512 pixels in size – the other side can be 512 pixels or less. For emoji, the video must be exactly 100×100 pixels in size Video duration must …

Docker and Kubernetes basics for developers

Docker Docker containers are much more lightweight compared to classic VMs as they leverage host OS instead of starting their own OS. Containers are using 2 features of Linux-based OS: Namespaces and Cgroups (Control Groups). Namespace Lets you allocate resources in an isolated environment (like a sandbox). On a container start, docker daemon generates a …

Go’s Concurrency and Channel Internals

Go is implementing CSP (Communicating Sequential Processing): processes are communicating through channels, they can block each other while waiting for read/writes to channels. Actor model makes inter-process communications more explicit and non-blocking. CSP vs Actor explained — https://dev.to/karanpratapsingh/csp-vs-actor-model-for-concurrency-1cpg. Channels requirements goroutine-safe store and pass data across goroutines FIFO can block/unblock goroutines

Protobuf: add header parameters

They finally added it to the grpc-gateway: https://github.com/grpc-ecosystem/grpc-gateway/pull/3010/files#diff-c255ac405628aada46c25a2c9765605e9f823bc523d3739fd3fa71d4bcbf5c99. So, to use it you can just update to the version 2.14.0 or above — https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v2.14.0, and add something like this to your protofile:

        option (grpc.gateway.protoc_gen_openapiv2.options.openapiv2_operation) = {
            summary: "Create a new foo.";
            parameters: {
                headers: {
                    name: "My-Custom-Header";
                    description: "Some custom header description";
                    required: true;
                };
            };
        };

option (grpc.gateway.protoc_gen_openapiv2.options.openapiv2_operation) = {

summary: "Create a new foo.";

parameters: {

headers: {

name: "My-Custom-Header";

description: "Some custom header description";

required: true;

};

Go scheduler details

Scheduler was implemented by Dmitry Vyukov in go 1.1 and lives in runtime/proc.go. Good resources https://www.youtube.com/watch?v=-K11rY57K7k — video by Dmitry Vyukov (slides as pdf) https://www.ardanlabs.com/blog/2018/08/scheduling-in-go-part2.html — nice article by Bill Kennedy in 3 parts. Most of the images below are taken from this article. Main ideas Goroutines are very light weight (~2KB+) and very cheap …

Golang. Adding a json body to POST request in protofile

It could be a bit tricky, and I failed to find a good example for it.

How to install Outline VPN on a random VPS server

In Ountline Manager, when you add a new server, select an option called «Set up Outline everywhere».