echo Error: curl is not installed or does not support https, wget is not installed. \
       Cannot download envoy. Please install wget or add support of https to curl.
  exit 1
}

# Downloads and extract an Envoy binary if the artifact doesn't already exist.
# Params:
#   $1: The URL of the Envoy tar.gz to be downloaded.
#   $2: The full path of the output binary.
#   $3: Non-versioned name to use