google-fluentd-modified.sh

#!/bin/bash
# Copyright 2015 Google Inc. All rights reserved.
#
# 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.

#
# Install and start the Google logging agent (google-fluentd).
#
# This script does the following:
#
#   1. Configures the required apt or yum repository.
#      The environment variable REPO_SUFFIX can be set to alter which
#      repository is used.  A dash (-) will be inserted prior to the supplied
#      suffix. Example values are 'unstable' or '20151027-1'.
#   2. Installs the logging agent.
#   3. Installs "catch-all" configuration files (unless the environment
#      variable DO_NOT_INSTALL_CATCH_ALL_CONFIG is set to suppress this.)
#   4. Starts the logging agent.
#   5. Sends a test message which should be visible in the log viewer.

# Name of the logging agent.
AGENT_NAME='google-fluentd'

# Name of the config files package.
CONFIG_NAME='google-fluentd-catch-all-config'

# Host that serves the repositories.
REPO_HOST='packages.cloud.google.com'

# URL for the cloud logging documentation
CLOUD_LOGGING_DOCS_URL="https://cloud.google.com/logging/docs/agent"

# Recent systems provide /etc/os-release. The ID variable defined therein
# is particularly useful for identifying Amazon Linux.
if [[ -f /etc/os-release ]]; then
  . /etc/os-release
fi

preinstall() {
  cat <<EOM
==============================================================================
Starting installation of ${AGENT_NAME}
==============================================================================

EOM
}

postinstall() {
  exit_code=0
  service ${AGENT_NAME} restart
  if [[ $? -eq 0 ]]; then
    logger "Test syslog message from ${AGENT_NAME}-${VERSION} at $(date)."

    fluentd_log="/var/log/${AGENT_NAME}/${AGENT_NAME}.log"
    logs_viewer_url=$(grep 'Logs viewer address: ' ${fluentd_log} | tail -1 |\
      sed -e 's/.*Logs viewer address: //')
    if [[ -z "$logs_viewer_url" ]]; then
      logs_viewer_url="(failed to obtain logs viewer URL from agent log)"
    fi

    cat <<EOM

==============================================================================
Installation of ${AGENT_NAME} complete.

Logs from this machine should be visible in the log viewer at:
  ${logs_viewer_url}

A test message has been sent to syslog to help verify proper operation.

Please consult the documentation for troubleshooting advice:
  ${CLOUD_LOGGING_DOCS_URL}

You can monitor the logging agent's logfile at:
  ${fluentd_log}
==============================================================================
EOM

    # Prints an additional banner if we appear to have a credentials issue.
    check_credentials
  else
    cat <<EOM

==============================================================================
Errors occurred while installing ${AGENT_NAME}-${VERSION}. See the log snippet
above or run:
  sudo service ${AGENT_NAME} status
==============================================================================
EOM
    exit_code=1
  fi

  return "$exit_code"
}

install_for_debian() {
  # TODO: CODENAME should be incorporated into the repo name, but for now the
  # wheezy packages work on all supported Debian and Ubuntu systems.
  local CODENAME="$(lsb_release -sc)"
  local REPO_NAME="google-cloud-logging-wheezy${REPO_SUFFIX+-${REPO_SUFFIX}}"
  cat > /etc/apt/sources.list.d/google-cloud-logging.list <<EOM
deb http://${REPO_HOST}/apt ${REPO_NAME} main
EOM
  curl -s -f https://${REPO_HOST}/apt/doc/apt-key.gpg | apt-key add -
  apt-get -qq update -o Dir::Etc::sourcelist="sources.list.d/google-cloud-logging.list" \
                     -o Dir::Etc::sourceparts="-" -o APT::Get::List-Cleanup="0"

  local PACKAGES="$AGENT_NAME"
  if [[ -z "${DO_NOT_INSTALL_CATCH_ALL_CONFIG+unset}" ]]; then
    PACKAGES+=" $CONFIG_NAME"
  fi
  DEBIAN_FRONTEND=noninteractive apt-get -y -qq install ${PACKAGES}
  VERSION=`dpkg -l google-fluentd | tail -n 1 |\
    sed -E 's/.*([0-9]+\.[0-9]+\.[0-9]+-[0-9]+).*/\1/'`
}

# takes the repo name as a parameter
install_rpm() {
  local REPO_NAME="${1}${REPO_SUFFIX+-${REPO_SUFFIX}}"
  cat > /etc/yum.repos.d/google-cloud-logging.repo <<EOM
[google-cloud-logging]
name=Google Cloud Logging Agent Repository
baseurl=https://${REPO_HOST}/yum/repos/${REPO_NAME}
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://${REPO_HOST}/yum/doc/yum-key.gpg
       https://${REPO_HOST}/yum/doc/rpm-package-key.gpg
EOM
  local PACKAGES="$AGENT_NAME"
  if [[ -z "${DO_NOT_INSTALL_CATCH_ALL_CONFIG+unset}" ]]; then
    PACKAGES+=" $CONFIG_NAME"
  fi
  yum -y -q install ${PACKAGES}
  VERSION=`yum list google-fluentd.x86_64 | tail -n 1 |\
    sed -E 's/.*([0-9]+\.[0-9]+\.[0-9]+-[0-9]+).*/\1/'`
}

install_for_redhat() {
  local VERSION_PRINTER='import platform; print(platform.dist()[1].split(".")[0])'
  local MAJOR_VERSION=$(python -c "${VERSION_PRINTER}")
  local REPO_NAME="google-cloud-logging-el${MAJOR_VERSION}-\$basearch"
  install_rpm ${REPO_NAME}
}

install_for_amazon_linux() {
  local REPO_NAME="google-cloud-logging-el6-\$basearch"
  install_rpm ${REPO_NAME}
}

check_credentials() {
  if curl -s -i http://169.254.169.254 | \
      grep -i '^Metadata-Flavor: Google' > /dev/null 2>&1; then
    # running on GCP; we can get credentials from the built-in service account.
    return
  fi

  # Check for GOOGLE_APPLICATION_CREDENTIALS, which might be set in
  # /etc/sysconfig or /etc/default.
  [[ -f /etc/sysconfig/${AGENT_NAME} ]] && source /etc/sysconfig/${AGENT_NAME}
  [[ -f /etc/default/${AGENT_NAME} ]] && source /etc/default/${AGENT_NAME}
  if [[ -n "$GOOGLE_APPLICATION_CREDENTIALS" && \
        -f "$GOOGLE_APPLICATION_CREDENTIALS" ]]; then
    return
  fi

  # Look at the user and system default paths.
  for path in /root/.config/gcloud/application_default_credentials.json \
      /etc/google/auth/application_default_credentials.json; do
    if [[ -f "$path" ]]; then
      return
    fi
  done

  cat <<EOM

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
WARNING: Google Compute Platform credentials are required for this platform
but were not found, thus the agent may have failed to start or initialize
properly.  Please consult the "Authorization" section of the documentation at
${CLOUD_LOGGING_DOCS_URL} then restart the agent using:

  sudo service ${AGENT_NAME} restart
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

EOM
}

install() {
  case "${ID:-}" in
    amzn)
      echo 'Installing agents for Amazon Linux.'
      install_for_amazon_linux
      ;;
    debian|ubuntu)
      echo 'Installing agents for Debian or Ubuntu.'
      install_for_debian
      ;;
    rhel|centos)
      echo 'Installing agents for RHEL or CentOS.'
      install_for_redhat
      ;;
    *)
      # Fallback for systems lacking /etc/os-release.
      if [[ -f /etc/debian_version ]]; then
        echo 'Installing agents for Debian.'
        install_for_debian
      elif [[ -f /etc/redhat-release ]]; then
        echo 'Installing agents for Red Hat.'
        install_for_redhat
      else
        echo >&2 'Unidentifiable or unsupported platform.'
        exit 1
      fi
  esac
}

main() {
  preinstall

  if ! install; then
    echo >&2 'Installation failed.'
    exit 1
  fi

  #postinstall
  return $?
}

main "$@"