Bash script that can download an asset from a private Github repository

download_asset_from_private_github_repo.sh

#!/usr/bin/env bash

# Prerequisites: curl, jq, and a GitHub token (provided as environment variable `GITHUB_TOKEN`)

set -e

ORG=${ORG:-"your-default-org"}
REPO=${REPO:-"your-default-repo"}
API_URL="https://api.github.com/repos/${ORG}/${REPO}"
ARCH=${ARCH:-"linux_amd64"}

# Verify that the required environment variables are set
if [ -z "${TAG}" ]; then
  echo "TAG environment variable is not set"
  exit 1
fi
if [ -z "${GITHUB_TOKEN}" ]; then
  echo "GITHUB_TOKEN environment variable is not set"
  exit 1
fi

# Determine the identifier of the asset
echo "Determining asset identifier for ${API_URL}/releases/tags/${TAG} (file that contains '${ARCH}' in its name) ..."
curl --fail -sSL \
  -H "Authorization: token ${GITHUB_TOKEN}" \
  -H "Accept: application/vnd.github+json" \
  "${API_URL}/releases/tags/${TAG}" > all_assets_for_tag.json
jq -r '.assets[] | select(.name | contains("'"${ARCH}"'"))' < all_assets_for_tag.json > asset_info.json
ASSET_ID=$(jq -r '.id' < asset_info.json)
ASSET_NAME=$(jq -r '.name' < asset_info.json)
echo "Asset identifier: ${ASSET_ID}, file name: ${ASSET_NAME}"
rm all_assets_for_tag.json asset_info.json

# Download the asset, based on its identifier
echo "Downloading asset: ${API_URL}/releases/assets/${ASSET_ID} (${ASSET_NAME}) ..."
rm ${ASSET_NAME} || true
curl --fail -sSL -JO \
  -H "Authorization: token ${GITHUB_TOKEN}" \
  -H "Accept: application/octet-stream" \
  "${API_URL}/releases/assets/${ASSET_ID}"