src/data/read_cos_env.yaml

#cloud-config
#
# Copyright 2025 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Collects environmental data from the COS VM and logs it

write_files:
- path: /tmp/startup.sh
  permissions: 0644
  content: |
    set +o history
    set -o errexit
    set -o pipefail
    set -o nounset
    set -x

    status() {
      "$@" 2>&1 | sed "s/^/EnvStatus: /"
      return "${PIPESTATUS[0]}"
    }

    main() {
      status history -c
      cat <<EOF > /tmp/cos_env.json
    {
      "osRelease": "",
      "lsbRelease": "",
      "toolchainPath": "",
      "kernelRelease": "$(uname -r)",
      "arch": "$(uname -m)"
    }
    EOF
      jq \
        --rawfile osRelease /etc/os-release \
        --rawfile lsbRelease /etc/lsb-release \
        --rawfile toolchainPath /etc/toolchain-path \
        '.osRelease = $osRelease | .lsbRelease = $lsbRelease | .toolchainPath = $toolchainPath' \
        /tmp/cos_env.json > /tmp/cos_env.json.new
      status mv /tmp/cos_env.json.new /tmp/cos_env.json
      status echo "ENVRESULT $(base64 -w0 /tmp/cos_env.json)"
    }

    main
    if [[ $? == 0 ]]; then
      echo "EnvSucceeded: Shutting down..."
    else
      echo "EnvFailed: Shutting down..."
    fi
    sleep 10
    shutdown -h now
    while true; do sleep 1; done

- path: /etc/systemd/system/envreader@.service
  permissions: 0644
  content: |
    [Unit]
    Description=Container-Optimized OS Environment Reader
    Wants=network-online.target
    After=network-online.target

    [Service]
    Type=oneshot
    RemainAfterExit=yes
    User=root
    ExecStart=/bin/bash /tmp/startup.sh
    ExecStopPost=/bin/bash -c 'rm /etc/systemd/system/envreader@.service'
    StandardOutput=tty
    StandardError=tty
    TTYPath=%I

runcmd:
- echo "Starting env reader..."
- systemctl daemon-reload
- |
  if [[ "$(uname -m)" == "aarch64" ]]; then
    systemctl --no-block start envreader@-dev-ttyAMA2.service
  else
    systemctl --no-block start envreader@-dev-ttyS2.service
  fi