Import the sourcecred.github.io deploy script (#532)

This copies the deploy script from sourcecred/sourcecred.github.io into
the sourcecred/sourcecred repository. It's been modified to reflect the
fact that it is no longer run from within the sourcecred.github.io
repository.

We’re moving this script into the main SourceCred repository so that it
can be versioned in the same tree as everything else, and in particular
so that the hash-of-built-commit depends on the build script itself.

The script was originally created by @wchargin in
https://github.com/sourcecred/sourcecred.github.io/pull/1 at hash
e8bc5b669b31df34b439b194cb62af4fd9a789d8, subsequently modified in
https://github.com/sourcecred/sourcecred.github.io/pull/2 and
https://github.com/sourcecred/sourcecred.github.io/pull/3 and
https://github.com/sourcecred/sourcecred.github.io/pull/4

Paired with @wchargin

Test plan: Ran locally (on dry-run) and inspected output.

scripts/deploy.sh

@@ -0,0 +1,146 @@
+#!/bin/sh
+set -eu
+
+: "${SOURCECRED_REMOTE:=git@github.com:sourcecred/sourcecred.git}"
+: "${SOURCECRED_REF:=origin/master}"
+
+: "${DEPLOY_REMOTE:=git@github.com:sourcecred/sourcecred.github.io.git}"
+: "${DEPLOY_BRANCH:=master}"
+
+export GIT_CONFIG_NOSYSTEM=1
+export GIT_ATTR_NOSYSTEM=1
+
+main() {
+    parse_args "$@"
+
+    toplevel="$(git -C "$(dirname "$0")" rev-parse --show-toplevel)"
+    cd "${toplevel}"
+
+    sourcecred_repo=
+    sourcecred_site=
+    preview_dir=
+    trap cleanup EXIT
+
+    ensure_clean_working_tree
+    build_and_deploy
+}
+
+parse_args() {
+    while [ $# -gt 0 ]; do
+        case "$1" in
+            -n|--dry-run)
+                printf 'Setting DRY_RUN=1.\n'
+                DRY_RUN=1
+                ;;
+            *)
+                printf >&2 'unknown argument: %s\n' "$1"
+                exit 1
+                ;;
+        esac
+        shift
+    done
+}
+
+# Adapted from:
+# https://github.com/git/git/blob/8d530c4d64ffcc853889f7b385f554d53db375ed/git-sh-setup.sh#L207-L222
+ensure_clean_working_tree() {
+    err=0
+    if ! git diff-files --quiet --ignore-submodules; then
+        printf >&2 'Cannot deploy: You have unstaged changes.\n'
+        err=1
+    fi
+    if ! git diff-index --cached --quiet --ignore-submodules HEAD -- ; then
+        if [ "${err}" -eq 0 ]; then
+            printf >&2 'Cannot deploy: Your index contains uncommitted changes.\n'
+        else
+            printf >&2 'Additionally, your index contains uncommitted changes.\n'
+        fi
+        err=1
+    fi
+    if [ "${err}" -ne 0 ]; then
+        exit "${err}"
+    fi
+}
+
+build_and_deploy() {
+    sourcecred_data="$(mktemp -d --suffix ".sourcecred-data")"
+    export SOURCECRED_DIRECTORY="${sourcecred_data}"
+
+    sourcecred_repo="$(mktemp -d --suffix ".sourcecred-repo")"
+    git clone "${SOURCECRED_REMOTE}" "${sourcecred_repo}"
+    sourcecred_hash="$(
+        git -C "${sourcecred_repo}" rev-parse --verify "${SOURCECRED_REF}" --
+    )"
+    git -C "${sourcecred_repo}" checkout --detach "${sourcecred_hash}"
+    (
+        cd "${sourcecred_repo}"
+        yarn
+        yarn backend
+        yarn build
+        node ./bin/sourcecred.js load sourcecred example-github
+        node ./bin/sourcecred.js load sourcecred example-git
+        node ./bin/sourcecred.js load sourcecred sourcecred
+    )
+
+    sourcecred_site="$(mktemp -d --suffix ".sourcecred-site")"
+    git clone "${DEPLOY_REMOTE}" "${sourcecred_site}"
+
+    if ! base_commit="$(
+            git -C "${sourcecred_site}" rev-parse --verify \
+              "refs/remotes/origin/${DEPLOY_BRANCH}" --
+    )"; then
+        printf >&2 'No deploy branch %s.\n' "${DEPLOY_BRANCH}"
+        exit 1
+    fi
+    git -C "${sourcecred_site}" checkout --detach "${base_commit}"
+    rm "${sourcecred_site}/.git/index"
+    git -C "${sourcecred_site}" clean -qfdx
+    # Explode the `build/` directory into the current directory.
+    find "${sourcecred_repo}/build/" -mindepth 1 -maxdepth 1 \
+        \( -name .git -prune \) -o \
+        -exec cp -r -t "${sourcecred_site}" -- {} +
+    # Copy the SourceCred data into the appropriate API route.
+    mkdir "${sourcecred_site}/api/"
+    mkdir "${sourcecred_site}/api/v1/"
+    cp -r "${sourcecred_data}" "${sourcecred_site}/api/v1/data"
+    git -C "${sourcecred_site}" add --all .
+    git -C "${sourcecred_site}" commit -m "deploy-v1: ${sourcecred_hash}"
+    deploy_commit="$(git -C "${sourcecred_site}" rev-parse HEAD)"
+
+    preview_dir="$(mktemp -d --suffix ".sourcecred-prvw")"
+    git clone -q --no-local --no-checkout "${sourcecred_site}" "${preview_dir}"
+    git -C "${preview_dir}" checkout -q --detach "${deploy_commit}"
+
+    printf '\n'
+    printf 'Please review the build output now---run:\n'
+    printf '    cd "%s" && python -m SimpleHTTPServer\n' "${preview_dir}"
+    printf 'Do you want to deploy? yes/no> '
+    read -r line
+    if [ "${line}" = yes ]; then
+        (
+            set -x;
+            git -C "${sourcecred_site}" push ${DRY_RUN:+--dry-run} \
+                origin \
+                "${deploy_commit}:${DEPLOY_BRANCH}" \
+                ;
+        )
+    else
+        printf 'Aborting.\n'
+    fi
+
+    printf 'Done.\n'
+}
+
+cleanup() {
+    if [ -d "${sourcecred_site}" ]; then
+        rm -rf "${sourcecred_site}"
+    fi
+    if [ -d "${sourcecred_repo}" ]; then
+        rm -rf "${sourcecred_repo}"
+    fi
+    if [ -d "${preview_dir}" ]; then
+        rm -rf "${preview_dir}"
+    fi
+}
+
+main "$@"