[SOLVED] debsig-verify for Failed verification error, “signatures using the SHA1 algorithm are rejected” and “Can’t check signature: Invalid digest algorithm”

Posted on by rchapin

If you are using debsig-verify for the verification of a downloaded .deb file and are unable to verify it, run it with the -d option to get more information. If you see the following two lines

gpg: Note: signatures using the SHA1 algorithm are rejected
gpg: Can't check signature: Invalid digest algorithm

It is likely that the PGP signature used to sign the package uses the SHA1 algorithm which has been deprecated in most of the recent Linux distros. If → Continue reading “[SOLVED] debsig-verify for Failed verification error, “signatures using the SHA1 algorithm are rejected” and “Can’t check signature: Invalid digest algorithm””

Query for Finding the nth Element in a PostgreSQL JSONB Array that Matches a Specified Value

Posted on by rchapin

The following is a sample query that you can use to search for rows that have the nth element in a JSONB array that match a specific value.

Given

CREATE TABLE sample_jsonb (
  id serial PRIMARY KEY,
  name varchar(64),
  json_data jsonb
);

INSERT INTO sample_jsonb(name, json_data)
VALUES
  ('foo',
  '{
  "key": "val1",
  "arr": ["homer", "bart", "barney"]
  }'),
  ('bar',
  '{
  "key": "val2",
  "arr": ["marge", "lisa", "maggie"]
  }'),
  ('baz',
  '{
  "key": "val2",
  "arr": ["bart", "milhouse", "nelson"]
  }')
;

We now have two records → Continue reading “Query for Finding the nth Element in a PostgreSQL JSONB Array that Matches a Specified Value”

LVM Resize – reduce the size of one logical volume to enable expanding another

Posted on by rchapin

I’m running an Ubuntu workstation and when setting it up simply went the “next-next-next” route when setting up the encrypted disk via LVM. The default is to create a 1G swap partition which is just not enough when you attempt to run too many things and locks up and/or crashes the machine.

My goal was to reduce my /root partition and then use that space to extend my swap partition.

Ensure that you back up your data first! There is → Continue reading “LVM Resize – reduce the size of one logical volume to enable expanding another”

Query for Finding an Element in a PostgreSQL JSONB Array

Posted on by rchapin

The following is a sample query that you can use to search for rows that have an element in a JSONB array.

Given

CREATE TABLE sample_jsonb (
  id serial PRIMARY KEY,
  name varchar(64),
  json_data jsonb
);

INSERT INTO sample_jsonb(name, json_data)
VALUES
  ('foo',
  '{
  "key": "val1",
  "arr": ["homer", "bart", "barney"]
  }'),
  ('bar',
  '{
  "key": "val2",
  "arr": ["marge", "lisa", "maggie"]
  }')
;

select count(*) from sample_jsonb where json_data-'arr' ? 'marge';
→ Continue reading “Query for Finding an Element in a PostgreSQL JSONB Array”

Convert a Slice of Any Type to a CSV in Go

Posted on by rchapin

There are times, mostly for logging and debugging, when you have a slice of a given type that you would like to print to a log file or just convert to a CSV of values.

A quick and easy way to convert a slice to a CSV in Golang is to use the json module to Marshal it a JSON encoded array.

For example

package main

import (
	"encoding/json"
	"fmt"
)

func main() {
	ints := []int64{1, 2, 3,
→ Continue reading “Convert a Slice of Any Type to a CSV in Go”

PostgreSQL Query to Find Tables With Name LIKE

Posted on by rchapin

Sometimes you are working with a PostgreSQL database with A LOT of tables and looking for tables that contain a sub-string in their name. Following is a query that you can run that will return all of the tables that have the string in their name:

SELECT
  table_schema,
  table_name
FROM
  information_schema.tables
WHERE
      table_name LIKE '%<string%'
  AND table_schema not in ('information_schema', 'pg_catalog')
  AND table_type = 'BASE TABLE'
ORDER BY
  table_name, table_schema
;
→ Continue reading “PostgreSQL Query to Find Tables With Name LIKE”

Earthly Cheat Sheet

Posted on by rchapin

I have just recently started using Earthly and the following is a list of commands that I want to keep track of

Caching

Completely clearing the cache: Earthly stores artifacts in docker volumes. If you want to completely flush that data and start fresh run the following

docker stop earthly-buildkitd && \
docker rm earthly-buildkitd && \
docker volume rm earthly-cache
→ Continue reading “Earthly Cheat Sheet”

git Cheat Sheet

Posted on by rchapin

A handful of handy git commands that I don’t use all that often but want to keep track of:

Stashing

Stash a single file

git stash push -m 'message here' -- path/to/file

Drop a specific stash

First figure out the id of the stash you want to drop with git stash list, then issue the following command

git stash drop stash@{n}

Editing Commits

Changing author of already pushed commit

If you need to change the author of a commit → Continue reading “git Cheat Sheet”

Use printf to join an array in Bash

Posted on by rchapin

If you would like to join an array of elements with a defined delimiter in Bash there is an easy way to go about it by using printf. Following is an example

#!/bin/bash

declare -a arr=()

for i in `seq 1 5`
do
  arr=("${arr[@]}" $i)
done

# Generate a single string joined by a comma.  The printf string can contain
# any arbitrary delimiter.
printf -v joined '%s,' "${arr[@]}"

# Print out the string minus the trailing comma
echo
→ Continue reading “Use printf to join an array in Bash”

Specifying a commit in go.mod instead of a local replace for development

Posted on by rchapin

Sometimes you are making changes to a dependency in another of your go projects and instead of adding a replace command in the go.mod file you want to update that entry in go.mod to point to a specific commit in the repo.

To do so, all that you need to do is:

  1. Get the git commit that you want included in your build
  2. Change directories to the same directory that your project’s go.mod file resides in which you want to
→ Continue reading “Specifying a commit in go.mod instead of a local replace for development”
© 2005 Ryan Chapin