ahjohannessen

Scala Collaboration Profile

Last reviewed: 2026-06-18 Review cadence: monthly

Instructions for the Assistant

Treat this document as a working agreement for technical discussions.

The primary purpose of this document is to transfer context into a fresh conversation and approximate the benefits of a long-running collaboration.

ahjohannessen

Nginx TLS SNI routing, based on subdomain pattern

Nginx can be configured to route to a backend, based on the server's domain name, which is included in the SSL/TLS handshake (Server Name Indication, SNI).
This works for http upstream servers, but also for other protocols, that can be secured with TLS.

prerequisites

• at least nginx 1.15.9 to use variables in ssl_certificate and ssl_certificate_key.
• check nginx -V for the following:

  ...
  TLS SNI support enabled

ahjohannessen

#!/usr/bin/env bash

# Update a Flatcar installation on VMWare to use the latest OEM content
#
# Copyright 2020, Neil Mayhew <neil@kerith.ca>
# LICENSE: MIT

set -ex
shopt -s extglob nullglob

ahjohannessen

{"ignition":{"config":{},"security":{"tls":{}},"timeouts":{},"version":"2.2.0"},"networkd":{"units":[{"contents":"[Match]\nName=en[s,o]*\n\n[Network]\nAddress=192.168.103.201/24\nGateway=192.168.103.102\nDNS=8.8.8.8\n","name":"00-static.network"}]},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEArKvwajIJWpB4UPpQLqOCn/Y/g+xsmQa5Z8UFX/QZUpI/xeHgn64Zv+z3UJGKBpMXY33cwIi+1R/Vv1+CrEdZitqWlaBIlDfw+fClBgzqe/0QxaEEwQqX3bfxHZnNryy3YR7aOKiRNv1BnmuYiSyb87GHq+5x5mqw0pvyTqVANjEGJpbivHxTjiE7vJKG83IyzjE+c5ja8wE7HdfwiZ1YzLlD/t1uKz96IV3x1wC+Ku/xijkRHMmI8lCjFXgxCXdsm9hueFBxeH3hFaaFjU3shYzcBcZFRYVOCqbFRsYYtThoENg46j5pziYgPzALE0SSUOdK+nG8dTHk+qirkXgEyw== ahjohannessen@gmail.com","ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAliYIxuFOUwffcRBjk4reYkMyv0247f6GhnmnQMePrG9I8xr3l5bCIEeMLuiJJSKZXGwPx/HXFnaex9OMLREu235+6EcaybgjhYJlBx65BsTYoDm/RF8lXzwmHQer/ABzM2o+2i2pAbPK/LsLxmxUnQzfWBG7HZABJnNoMvUfrsqBOIjI/SA6+sIMsv2AQ9rIUzt4gmFTFfIGdNZsZ0LppEbaUTsB6sp4+UqxWomrgA4dpRw4ZGsiTjmbBe1maIsJrRI1ZWPuRSUKhAxQKBqz

ahjohannessen

pull_request_rules:
  - name: Assign and label scala-steward's PRs
    conditions:
      - author=scala-steward
    actions:
      assign:
        users: [ahjohannessen]
      label:
        add: [dependency-update]
  - name: Approve scala-steward patches

ahjohannessen

import shapeless._

@annotation.implicitNotFound("Make sure all cases of ${C} have an instance of ${TC}")
trait CopTCs[C <: Coproduct, TC[_]] {
  type Out <: HList
  def result: Out
}
object CopTCs {
  type Aux[C <: Coproduct, TC[_], O <: HList] = CopTCs[C, TC] { type Out = O }
  def apply[C <: Coproduct, TC[_]](implicit ev: CopTCs[C, TC]) = ev

ahjohannessen

import cats.{ ApplicativeError, MonadError }
import cats.data.{ Kleisli, OptionT }
import cats.effect.Sync
import cats.effect.concurrent.Ref
import cats.syntax.all._
import io.circe.generic.auto._
import io.circe.syntax._
import org.http4s._
import org.http4s.circe.CirceEntityDecoder._
import org.http4s.circe._

ahjohannessen

interp.configureCompiler(_.settings.YpartialUnification.value = true)

import $ivy.`org.tpolecat::doobie-core:0.5.3`

import cats._
import cats.effect._
import cats.implicits._
import doobie._
import doobie.implicits._

ahjohannessen

import doobie._
import doobie.implicits._

// Something for FunctionK ~>

trait Foo[F[_]]{ 
  def getFoo: F[Bar] 
}

ahjohannessen

import shapeless._
import shapeless.labelled._

trait Required[A] {
  def isRequired: Boolean
}
object Required {
  implicit def optIsRequired[A]: Required[Option[A]] = new Required[Option[A]] {
    override def isRequired = false
  }