wiki/tools.nix.reproducible-executables.org

Reproducible executables with Nix

You can create a reproducible executable that only requires Nix.

Here's a sample script that uses multiple dependencies.

If the script interact with the network (e.g., curl, wget) and the environment is completely pure, don't forget to install public Certificate Authorities with cacert.

#!/usr/bin/env nix-shell
#! nix-shell --pure -i bash -p coreutils curl cacert jq fzf findutils

# A quick command line interface for creating a gitignore with the API from https://gitignore.io.
# This script comes with a simple caching to avoid creating too much requests.

set -eo pipefail

CACHE_FILE="${XDG_CACHE_DIR:-$HOME/.cache}/gitignore-io.langs.json"

# Check if the language list is downloaded for the last hour (3600 seconds).
if [ ! -e $CACHE_FILE ] || test $(expr $(date "+%s") - $(date -r $CACHE_FILE "+%s")) -gt 3600
then
    ping "gitignore.io" --count 4 && curl --silent --location --output $CACHE_FILE "https://gitignore.io/api/list?format=json"
fi

KEYS=$(jq 'keys | .[] | @text' --raw-output $CACHE_FILE | fzf --multi | while read lang; do echo " .[\"$lang\"].contents"; done | paste -s -d ',')

jq "$KEYS" --raw-output $CACHE_FILE