vaultik/script/bootstrap

#!/bin/sh
# script/bootstrap: install all dependencies needed to build and develop
# this repo. Idempotent: every install is guarded by a check so already
# installed tools are skipped. Base tooling comes from nix, apt, brew,
# or apk (detected in that order); assumes NOTHING is present (not git,
# make, or go).
set -eu

ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"

PKGMGR=""
SUDO=""

detect_pkgmgr() {
    [ -n "$PKGMGR" ] && return 0
    if command -v nix-env >/dev/null 2>&1; then
        PKGMGR="nix"
    elif command -v apt-get >/dev/null 2>&1; then
        PKGMGR="apt"
    elif command -v brew >/dev/null 2>&1; then
        PKGMGR="brew"
    elif command -v apk >/dev/null 2>&1; then
        PKGMGR="apk"
    else
        echo "bootstrap: no supported package manager (nix, apt, brew, apk)" >&2
        exit 1
    fi
    if [ "$PKGMGR" = "apt" ]; then
        export DEBIAN_FRONTEND=noninteractive
        if [ "$(id -u)" != "0" ]; then
            SUDO="sudo"
        fi
    fi
}

# pkg_install <nix-attr> <apt-pkg> <brew-formula> <apk-pkg>
pkg_install() {
    detect_pkgmgr
    case "$PKGMGR" in
        nix) nix-env -iA "nixpkgs.$1" ;;
        apt) $SUDO env DEBIAN_FRONTEND=noninteractive apt-get install -y "$2" ;;
        brew) brew install "$3" ;;
        apk) apk add --no-cache "$4" ;;
    esac
}

missing() {
    ! command -v "$1" >/dev/null 2>&1
}

# Docker is a hard requirement, not a nice-to-have: script/lint lints by
# building Dockerfile.lint, whose digest-pinned golangci-lint image is
# the only place the linter runs, and script/check and script/precommit
# both run script/lint. A bootstrap that prints "bootstrap complete" on a
# machine where `make check` cannot run is a false success, so this fails
# instead.
#
# Installing docker from here was considered and rejected: it needs root,
# a running daemon, and on macOS a GUI cask, so an attempt would itself
# fail in the common case - trading one false success for a second
# failure mode. Naming exactly what breaks is more useful.
# Prints the problem and returns 0 when docker cannot be used; returns
# 1 (and prints nothing) when it can.
docker_problem() {
    if missing docker; then
        echo "docker is not installed"
        return 0
    fi
    if ! docker info >/dev/null 2>&1; then
        echo "the docker daemon is not reachable"
        return 0
    fi
    return 1
}

require_docker() {
    reason="$(docker_problem)" || return 0
    cat >&2 <<EOF
bootstrap: FAILED - $reason.

Docker is required to develop this repo. Without it these do not work:

  script/lint      builds Dockerfile.lint, which runs the linter as a
                   build step in a digest-pinned golangci-lint image.
                   That FROM line is the single source of truth for the
                   linter version
  script/check     runs script/lint
  script/precommit runs script/check, so commits are blocked by the
                   pre-commit hook installed by script/setup
  script/cibuild   builds Dockerfile.lint and Dockerfile, which is what
                   CI runs

Install docker (and start the daemon, checking DOCKER_HOST and your
group membership), then re-run script/bootstrap. golangci-lint on PATH
is deliberately not a substitute: script/lint will not use it.
EOF
    exit 1
}

main() {
    cd "$ROOT"

    # Base tooling (every repo)
    if missing git; then pkg_install git git git git; fi
    if missing make; then pkg_install gnumake make make make; fi

    # Go toolchain
    if missing go; then pkg_install go golang go go; fi

    # golangci-lint is deliberately NOT installed: script/lint lints by
    # building Dockerfile.lint, whose digest-pinned image is the only
    # place the linter runs, so whatever a package manager happens to
    # ship would only be a shadow of the pinned version that could drift
    # from CI. Nothing on the host is ever used as a linter, at any
    # version, so installing one here would buy nothing.

    # goreleaser, at the version pinned by script/install-goreleaser and
    # verified against a hardcoded sha256. Package managers are not used
    # for it: they ship whatever version they happen to carry, and the
    # tool that builds a release has to be a known one. The install is
    # its own script because the release workflow needs goreleaser
    # without needing the Docker requirement below.
    "$ROOT/script/install-goreleaser"

    go mod download

    # Last, so that everything installable is installed before the one
    # thing this script cannot install decides the outcome.
    require_docker

    echo "bootstrap complete"
}

main "$@"