Honkin' on the Fly

Running honk on fly.io

For those unaware—first of all, how? it’s literally everywhere—fly.io is the new platform-as-a-service du jour. The idea is to give them a Dockerfile (or a pre-built image, or just generic applications in a bunch of languages), and they run it for you on servers across the globe. Firecracker microVMs, WireGuard, and some other neat tech. Understandably, this gets the average Hacker News-type (me), excited. And I’d been meaning to switch my fediverse instance over to honk—a stateful Go application using sqlite1. And the fly.io folks really like sqlite. The stars have aligned.

I trust that you can figure out the initial setup bits like logging in to the dashboard and giving them your credit card info and praying that they don’t run you a bill of $5000 because you somehow blew through their free allowance resources. As I understand it, Fly “auto-scales”, so this scenario isn’t unlikely—however, they do offer some leniency. Luckily, the chances of me turning into a fedi-influencer (fedifluencer?) overnight are rather slim.

setup

They want a Dockerfile, so let’s give them one.

FROM golang:1.18-alpine AS builder
RUN apk add sqlite-dev build-base mercurial

WORKDIR /tmp/src
RUN hg clone https://humungus.tedunangst.com/r/honk 
RUN cd honk && make

FROM alpine:latest
RUN apk add sqlite sqlite-dev

COPY local /tmp/local
COPY memes /tmp/memes
COPY emus /tmp/emus

WORKDIR /opt
COPY --from=builder /tmp/src/honk/honk /bin/
COPY --from=builder /tmp/src/honk/views views/
COPY start /bin

ENV HONK_DATA_DIR "/opt/data"
ENV HONK_VIEWS_DIR "/opt/"

CMD ["/bin/start"]

Not too much going on here—we pull latest tip, build honk, copy the local directory containing our local.css (custom styles); the memes directory containing, well, memes (PNGs and GIFs); and the emus directory containing emoji (used as :filename:). These will then be copied into the Fly volume later on by the start script. Kinda gross, but whatever.

And the start script:

#!/bin/sh

run() {
    cp -R /tmp/memes/* "$HONK_DATA_DIR"/memes/
    cp -R /tmp/memes/* "$HONK_DATA_DIR"/emus/
    cp -R /tmp/local/* "$HONK_DATA_DIR"/views/

    honk -datadir "$HONK_DATA_DIR" -viewdir "$HONK_VIEWS_DIR"
}

# first time setup
if [ ! -f "$HONK_DATA_DIR/honk.db" ]; then
    honk init <<-EOF
    $HONK_USERNAME
    $HONK_PASSWORD
    $HONK_ADDRESS
    $HONK_SERVER_NAME
    EOF
fi

run

This simply copies our stuff from the container into the volume, and launches honk. If the honk database doesn’t yet exist, we run honk init and set it up. These environment variables are configured in the fly.toml file:

app = "honk"

kill_signal = "SIGINT"
kill_timeout = 5
processes = []

[mounts]
  source = "honkstore"
  destination = "/opt/data"

[env]
  HONK_USERNAME = "icy"
  HONK_ADDRESS = "0.0.0.0:8080"
  HONK_SERVER_NAME = "h.icyphox.sh"

[experimental]
  allowed_public_ports = []
  auto_rollback = true

[[services]]
  http_checks = []
  internal_port = 8080
  processes = ["app"]
  protocol = "tcp"
  script_checks = []

  [services.concurrency]
    hard_limit = 50
    soft_limit = 20
    type = "connections"

  [[services.ports]]
    force_https = true
    handlers = ["http"]
    port = 80

  [[services.ports]]
    handlers = ["tls", "http"]
    port = 443

  [[services.tcp_checks]]
    grace_period = "1s"
    interval = "15s"
    restart_limit = 0
    timeout = "2s"

The fly.toml gets generated when you first run fly launch. The only bits I’ve added are the env and mounts sections. Notice that HONK_PASSWORD is missing, and for good reason—Fly has support for secrets, which can be created quite handily using:

$ flyctl secrets set HONK_PASSWORD="$(pw -s honk)"

deploy

The only thing left to do is to provision our volume for persistence, and we’re off to the races:

$ flyctl volumes create honkstore --region maa
        ID: vol_1g67340omkm4ydxw
      Name: honkstore
       App: honk
    Region: maa
      Zone: aed0
   Size GB: 10
 Encrypted: true
Created at: 21 May 22 16:07 UTC

$ flyctl deploy

post-deploy

I like having pretty usernames. In this case, I want to drop the h. subdomain and have it look like this: icy@icyphox.sh. To do this, we simply set the masqname key in the database to our desired hostname2:

$ honk setconfig 'masqname' 'icyphox.sh'

And at icyphox.sh, we setup a redirect to h.icyphox.sh at the /.well-known/webfinger path. I did this via Netlify; you can do it however, as long as the query parameters are preserved. Read more about webfingers and other thingamabobs here.

I did a bunch more like custom CSS, avatars etc. but I’ll leave that as homework for you (honk(8) is mandatory reading!).

thoughts

On Fly: I think it’s neat. Rough edges? Sure. My deploy was stuck in pending; I had to delete it and re-create it for it to start working again. I lost my data in the process because volumes are attached to apps. Perhaps I should’ve waited and the problem would’ve fixed itself. Who knows?

And that’s the eternal problem with PaaS—there’s a layer of abstraction that you can’t ever pierce. You can’t truly know what the problem was unless they publish a post-mortem (or don’t). Anyway, in this case I’ll just chalk it up to teething issues.

Is it easier than simply building it on a server and running nohup ./honk & and calling it a day3? Not really. It’s more fun, I guess.

On honk: It’s refreshing. I liked running Pleroma + Soapbox (I still do, haven’t killed it yet), but it always felt alien to me. I didn’t understand the code, didn’t enjoy having to upgrade Elixir/Erlang OTP whatever, mix.deps get blah blah; a single Go binary + sqlite + HTML templates speaks to me.

Go follow me at icy@icyphox.sh. It’s why I even wrote this post. Not that I can see it, honk doesn’t have those ego-numbers.

You can find all the source code to deploy honk yourself here: https://git.icyphox.sh/honk


  1. Written by tedu. He’s a cool guy who runs and hacks OpenBSD. The honk source is a fun read.

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  2. Had to setup a custom domain for this: https://fly.io/docs/app-guides/custom-domains-with-fly/ ↩︎
  3. Yes that’s actually how I run a bunch of my services, including forlater.email!

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