There's lots still to do, see the issue list (as well as TODO.txt for some further ideas). If you want to contribute, perhaps connect with me (either via an issue or on IRC) before writing lots of code.
Because the GHCup installation from the host machine will be used as-is in the
containers of the workers, and because said containers run Ubuntu, the desired
GHC versions must be installed as follows with ghcup
:
ghcup -p x86_64-deb10-linux install ghc 8.10.7
This ensures that the GHCs will work in the Ubuntu container. Note that currently (2022-08), Ubuntu GHCs seem to work fine on Arch Linux, for example.
(This seems to be necessary with certain GHC versions only, and it's probably related to GHC #22268.)
Note: the worker needs bubblewrap 0.7.0, which is present in the Ubuntu repos only from Ubuntu 23.04. If you're running an older version of Ubuntu (or another system without version 0.7.0), build bubblewrap yourself.
# Note: earlyoom is only advised if you're deploying; not necessary on your local machine
sudo apt update && sudo apt install earlyoom bubblewrap make npm jq
# Change "-r 60" to "-r 3600" in /etc/default/earlyoom (less spammy logs)
sudo systemctl restart earlyoom
sudo apt install build-essential curl libffi-dev libffi7 libgmp-dev libgmp10 libncurses-dev libncurses5 libtinfo5 pkg-config
# Install ghcup: https://www.haskell.org/ghcup/ (skip HLS and stack)
# Open a new terminal to get ghcup in PATH
# Note: earlyoom is only advised if you're deploying; not necessary on your local machine
sudo pacman -Syu earlyoom bubblewrap make npm jq
sudo systemctl enable --now earlyoom
sudo pacman -S base-devel
# Install ghcup: https://www.haskell.org/ghcup/ (skip HLS and stack)
# Open a new terminal to get ghcup in PATH
# MAKE SURE TO INSTALL GHC FOR TARGET x86_64-deb10-linux
# See above in the 'GHCup target platform' section
git clone https://github.com/haskell/play-haskell --recurse-submodules
cd play-haskell
To build the server (that hosts the website but doesn't run any user code):
cd play-haskell-server
make
cabal build
To build the worker (that the server will connect to, and that runs user code (in a sandbox)):
cd play-haskell-worker
make # Or equivalently:
# make chroot ; make bwrap-files/systemd-run-shim ; make builders
# 'make chroot' is interactive, select en_US.UTF-8.
# 'make builders' takes a long time because it builds all packages that should
# be available on the playground with all GHCs you have installed with GHCup.
# If you want just a few of those GHCs to work in the playground, manually run:
# bwrap-files/mkbuildscript.sh 9.2.5
# bwrap-files/mkbuildscript.sh 8.10.7
# etc., once for each version you want to be available. Change available
# packages in bwrap-files/mkbuildscript.sh .
cabal build
Optionally, if the machine you're building on does not have enough RAM, do this and use cabal build -j1
:
sudo fallocate -l 4G /swapfile
sudo chmod go-rw /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile
During development:
make frontend-dependencies
in play-haskell-server/
whenever play-haskell-server/static/package.json changesmake frontend
in play-haskell-server/
whenever some *.ts
file for the frontend changesmake reload-pages
in play-haskell-server/
(or re-run cabal run play-haskell-server
) to reload mustache pages (or send SIGUSR1
)To run the server: (all in play-haskell-server/
)
adminpass.txt
(filename does not matter, but adjust below)cabal run gen-secret-key -- secretkey.txt
(filename does not matter, but adjust below)
$SERVER_PUBKEY
{http://}hostname{:port} $WORKER1_PUBKEY
in preload-workers.txt
, where the {}
parts are optional (if not given, uses https on port 443); that $WORKER1_PUBKEY
is produced by the steps to run a worker, see belowcabal run play-haskell-server -- --adminpassfile adminpass.txt --secretkey secretkey.txt --preloadworkers preload-workers.txt
(omit the --preloadworkers
if you didn't do that step)cabal run play-haskell-server -- --help
for more info on options; the server listens with http on port 8123 by defaultTo run a worker: (all in play-haskell-worker/
)
cabal run gen-secret-key -- secretkey.txt
(filename does not matter, but adjust below)
$WORKER1_PUBKEY
$SERVER_PUBKEY
in trustedkeys.txt
(filename does not matter, but adjust below)cabal run play-haskell-worker -- --secretkey secretkey.txt --trustedkeys trustedkeys.txt +RTS -N
cabal run play-haskell-worker -- --help
for more info on options; the worker listens with http on port 8124 by default, use a reverse proxy ssl terminator to get httpsOn example.com/admin
the server exposes a simple admin interface through which you can add and remove workers. If you don't want to add workers this way, use the --preloadworkers
flag described above.
Pasted snippets are stored in an SQLite database in the file pastes.db
.
The playground web client uses a simple API to submit jobs to the server; this API can also be used by others. Be aware that the server imposes simple IP-based rate-limiting on job requests; you might get back 429 responses if you submit too many jobs.
The API is as follows: POST
to /submit
on the playground server with the following JSON content:
{
"code": "main :: IO ()\nmain = print 42",
"version": "9.2.4", // or "8.10.7", or "9.6.0.20230210", etc.
"opt": "O1", // "O0", "O1" or "O2"
"output: "run" // "run", "core" or "asm"
}
The response will be a JSON object (with Content-Type: text/json
) that has one of the following forms:
{"err": "... an error message ..."}
or
{
"ec": 0, // exit code; 0 on success
"ghcout": "", // stderr output from GHC; GHC warnings/errors end up here
"sout": "42\n", // stdout from the program, empty if it didn't get to run
"serr": "", // stderr from the program, empty if it didn't get to run
"timesecs": 0.595881831 // time taken to run the job on the worker, excludes server queueing time
}