Author Archives: bullgare

How to safely update data in MySQL

CREATE TABLE IF NOT EXISTS my_tmp_copy LIKE my;

INSERT INTO my_tmp_copy
SELECT * FROM my;

UPDATE my_tmp_copy SET order_count = 5 WHERE customer_id > 0;

RENAME TABLE my TO my_old, my_tmp_copy TO my;

CREATE TABLE IF NOT EXISTS my_tmp_copy LIKE my;

INSERT INTO my_tmp_copy

SELECT * FROM my;

UPDATE my_tmp_copy SET order_count = 5 WHERE customer_id > 0;

RENAME TABLE my TO my_old, my_tmp_copy TO my;

Mock sql (sqlx) db on golang

I am using this library — https://pkg.go.dev/github.com/data-dog/go-sqlmock. That’s how you can use it for mocking db querying:

Backup your Spotify playlists and activity

* http://www.spotmybackup.com/ Simple tool to export all your data into a file. Also you can import it into your account. So it could be used to backup your Spotify data (uses json format, only track ids, no titles). * https://www.tunemymusic.com/ It allows to transfer data between different music services and also export to a csv …

Outline — simple and powerful vpn on your server

https://getoutline.org/ Just a couple of mouse clicks, and it will create a new droplet on DigitalOcean for you (or any other provider from the list). Very easy to install, and works good so far.

Fast and simple mock server app by swagger file

I’ve tried Mockoon for mocking by swagger/OpenAPI spec file, and it works pretty good. It autogenerates the response based on swagger format, and you are able to update any response field the way you want, save your changes and run the mock server with one click on the port you specify. It is a separate …

How to install multiple versions of go on mac m1

For instance, I want to try a new beta, go1.18beta2 (I check if it’s available on the download page). And I already have a regular go1.17, that I want to use as a default one. To do so, I need to do this:

go install golang.org/dl/go1.18beta2@latest
go1.18beta2 download

1 2	go install golang.org/dl/go1.18beta2@latest go1.18beta2 download

Then I can check if it’s okay — go1.18beta2 version #go …

Create SQS queues on localstack container start

Put this file to your filesystem as ←anyname.sh→:

#!/usr/bin/env bash

set -euo pipefail

# enable debug
# set -x


echo "configuring sqs"
echo "==================="
LOCALSTACK_HOST=localhost
AWS_REGION=eu-central-1


# https://docs.aws.amazon.com/cli/latest/reference/sqs/create-queue.html
create_queue() {
	local QUEUE_NAME_TO_CREATE=$1
	awslocal --endpoint-url=http://${LOCALSTACK_HOST}:4566 sqs create-queue --queue-name ${QUEUE_NAME_TO_CREATE} --region ${AWS_REGION} --attributes VisibilityTimeout=30
}

create_queue "queue2"
create_queue "queue1"

#!/usr/bin/env bash

set -euo pipefail

# enable debug

# set -x

echo "configuring sqs"

echo "==================="

LOCALSTACK_HOST=localhost

AWS_REGION=eu-central-1

# https://docs.aws.amazon.com/cli/latest/reference/sqs/create-queue.html

create_queue() {

local QUEUE_NAME_TO_CREATE=$1

awslocal --endpoint-url=http://${LOCALSTACK_HOST}:4566 sqs create-queue --queue-name ${QUEUE_NAME_TO_CREATE} --region ${AWS_REGION} --attributes VisibilityTimeout=30

}

create_queue "queue2"

create_queue "queue1"

For instance, ./localstack_bootstrap/sqs_bootstrap.sh. Don’t forget to run chmod +x ./localstack_bootstrap/sqs_bootstrap.sh. Add this line to your docker-compose.yml: — ./localstack_bootstrap:/docker-entrypoint-initaws.d/. So it could look like this:

services:
  localstack:
    container_name: aws_sqs
    hostname: sqs
    image: localstack/localstack:latest
    environment:
      - AWS_DEFAULT_REGION=ap-southeast-1
      - EDGE_PORT=4566
      - SERVICES=sqs
    ports:
      - '4566:4566'
    volumes:
      - "${TMPDIR:-/tmp/localstack}:/tmp/localstack"
      - "/var/run/docker.sock:/var/run/docker.sock"
      - ./localstack_bootstrap:/docker-entrypoint-initaws.d/

services:

localstack:

container_name: aws_sqs

hostname: sqs

image: localstack/localstack:latest

environment:

- AWS_DEFAULT_REGION=ap-southeast-1

- EDGE_PORT=4566

- SERVICES=sqs

ports:

- '4566:4566'

volumes:

- "${TMPDIR:-/tmp/localstack}:/tmp/localstack"

- "/var/run/docker.sock:/var/run/docker.sock"

- ./localstack_bootstrap:/docker-entrypoint-initaws.d/

Then your queues can be reached by URLs http://localhost:4566/000000000000/queue1 and http://localhost:4566/000000000000/queue2. Further reading: https://docs.aws.amazon.com/cli/latest/reference/sqs/create-queue.html https://joerg-pfruender.github.io/software/docker/microservices/testing/2020/01/25/Localstack_in_Docker.html

Postgresql index naming convention

Use the table name as the prefix. Use the following suffixes: _pkey for a Primary Key constraint _key for a Unique constraint _excl for an Exclusion constraint _idx for any other kind of index _fkey for a Foreign key _check for a Check constraint https://stackoverflow.com/a/4108266/801426 Also implicitly mentioned here — https://www.postgresql.org/docs/current/sql-altertable.html

Heroes 3 on MacOS with M1 Apple Silicon

Initial installation 1. You need Parallels Desktop with M1 support — https://www.parallels.com/ru/products/desktop/trial/ 2. Also you need an insider account on Microsoft web site to download win 11 for arm — https://insider.windows.com/ru-ru/ 3. Then you need to download Win 11 for arm — https://www.microsoft.com/en-us/software-download/windowsinsiderpreviewARM64 4. Download Heroes 3 Hota on the internet (many links are there). …

FreeCAD to generate gcode

You should switch Workbench to «Mesh Design», then select your shape in the left bar, and go to Menu→Meshes→Create Mesh from the shape. More details on parameters — https://www.xsim.info/articles/FreeCAD/en-US/HowTo/Create-surface-meshes-from-solids.html