tools/devshell/build-metrics

#!/bin/bash
# Copyright 2022 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

#### CATEGORY=Other
### manage build metrics configuration

## usage:
##  fx build-metrics status
##       Show if build metrics collection is enabled or disabled
##
##  fx build-metrics enable
##       Enable build metrics collection in fx build.
##
##  fx build-metrics disable
##       Disable build metrics collection in fx build.
##
## If you opt-in to metrics collection, data will be collected and used by
## Google in accordance with the Google privacy policy
## (https://policies.google.com/privacy)

set -e

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/lib/vars.sh || exit $?
source "${FUCHSIA_DIR}/tools/devshell/lib/style.sh" || exit $?

readonly BUILD_METRICS_CONFIG="${FUCHSIA_DIR}/.fx-build-metrics-config"

function usage {
  show-what-is-collected
  fx-command-help
}

function show-what-is-collected {
  cat <<EOF
When enabled, fx builds will upload anonymized remote build logs
to collect valuable build performance data.

1. For every "fx build" invocation that uses remote building (RBE):
   - Reproxy logs containing details about every remote build action,
     e.g. timing breakdown, cache hit/miss, statuses, internal errors.

Each build can be identified by a UUID (not traceable to any user),
but can be voluntarily referenced in bug reports and triage sessions.

EOF
}

function describe-privacy-policy {
  cat << EOF
If you opt-in to logs collection, data will be collected and used by Google
in accordance with the Google privacy policy
(https://policies.google.com/privacy)
EOF
}

function styled-status {
  local enabled="$1"
  local metrics_status
  if [[ "$BUILD_METRICS_ENABLED" -eq 1 ]]; then
    metrics_status="enabled"
    color="green"
  else
    metrics_status="disabled"
    color="red"
  fi
  style::echo --bold "--${color}" "${metrics_status}"
}

fx-standard-switches "$@"
set -- "${FX_ARGV[@]}"

if [[ $# -lt 1 ]]; then
  fx-error Invalid syntax
  fx-command-help
  exit 1
fi

action="$1"

function build-metrics-read-config {
  BUILD_METRICS_ENABLED=0
  if [[ ! -f "${BUILD_METRICS_CONFIG}" ]]; then
    return 1
  fi
  source "${BUILD_METRICS_CONFIG}"
  return 0
}

function build-metrics-write-config {
  local enabled="$1"
  local -r tempfile="${BUILD_METRICS_CONFIG}.tmp"

  cat > "${tempfile}" <<EOF
# Autogenerated config file for 'fx build-metrics'.
# Run 'fx help build-metrics' for more information.
BUILD_METRICS_ENABLED=${enabled}
EOF
  # Only rewrite the config file if content has changed
  if ! cmp --silent "${tempfile}" "${BUILD_METRICS_CONFIG}"
  then mv -f "${tempfile}" "${BUILD_METRICS_CONFIG}"
  else rm -f "${tempfile}"
  fi
}

# Read config in a way that exit code is preserved but doesn't exit because
# of "set -e" if config file doesn't exist
__successfully_read_config=0
build-metrics-read-config || __successfully_read_config="$?"

case "$action" in
  -h|--help)
    usage
    exit 0
    ;;

  status)
    echo "Collection of build metrics is currently $(styled-status "$BUILD_METRICS_ENABLED") for ${FUCHSIA_DIR}"
    echo "To change it, run: fx build-metrics <enable|disable>"
    if [[ "$BUILD_METRICS_ENABLED" -eq 1 ]]; then
      echo
      show-what-is-collected
    fi
    exit 0
    ;;

  enable)
    describe-privacy-policy
    if [[ "$BUILD_METRICS_ENABLED" -eq 1 ]]; then
      echo "Build metrics collection is already enabled."
      exit 0
    fi
    uuidgen_cmd=uuidgen
    if ! command -v "$uuidgen_cmd" >/dev/null 2>&1 ; then
      fx-error "Command '$uuidgen_cmd' cannot be found, please add it to your PATH."\
               "(On Ubuntu/Debian systems, try \`sudo apt install uuid-runtime\`.)"
      exit 1
    fi
    # We don't need to generate a UUID until `fx build` time,
    # specifically, when build/rbe/fuchsia-reproxy-wrap.sh is invoked.

    # The python scripts that work with logs need protobuf code to
    # be generated in advance.  This includes building protoc.
    _setup_script=build/rbe/proto/refresh.sh
    echo "Fetching and generating necessary protobuf code (may take a few minutes)."
    "${FUCHSIA_DIR}"/"$_setup_script" > /dev/null || {
      fx-error "Re-run $_setup_script manually to look for errors."
      exit 1
    }

    BUILD_METRICS_ENABLED=1
    build-metrics-write-config "${BUILD_METRICS_ENABLED}"
    echo "Build metrics collection enabled at user's request"
    ;;

  disable)
    if [[ "$BUILD_METRICS_ENABLED" -eq 0 ]]; then
      if [[ "${__successfully_read_config}" -ne 0 ]]; then
        # if metrics is already disabled but the config file does not exist or
        # is inconsistent, we rewrite the file before exiting
        build-metrics-write-config "${BUILD_METRICS_ENABLED}"
      fi
      echo "Build metrics collection is already disabled."
      exit 0
    fi
    BUILD_METRICS_ENABLED=0
    build-metrics-write-config "${BUILD_METRICS_ENABLED}"
    echo "Build metrics collection disabled at user's request"
    ;;

  *)
    fx-error Invalid syntax
    fx-command-help
    exit 1
esac

echo "Collection of build metrics is now $(styled-status "$BUILD_METRICS_ENABLED") for ${FUCHSIA_DIR}"