SO webapp-ify the frontend (#82)

* webapp-ify

* Tweak values

* Self-contained

build-webapp.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+PKG_DIR="./packages/frontend"
+OUTPUT_DIR="${PKG_DIR}/build"
+DEST_DIR=${1:-/data}
+
+if [[ -d "$DEST_DIR" ]]; then
+  echo "${DEST_DIR} already exists." 1>&2
+  exit 1
+fi
+
+cat > $PKG_DIR/.env <<EOF
+REACT_APP_GQL_SERVER_URL = 'LACONIC_HOSTED_CONFIG_app_gql_url'
+REACT_APP_GITHUB_CLIENT_ID = 'LACONIC_HOSTED_CONFIG_app_github_clientid'
+REACT_APP_GITHUB_TEMPLATE_REPO = 'LACONIC_HOSTED_CONFIG_app_github_templaterepo'
+EOF
+
+yarn || exit 1
+yarn build || exit 1
+
+if [[ ! -d "$OUTPUT_DIR" ]]; then
+  echo "Missing output directory: $OUTPUT_DIR" 1>&2
+  exit 1
+fi
+
+mv "$OUTPUT_DIR" "$DEST_DIR"