MySQL Process List redirect to STDOUT

mysql_process_list_to_stdout.sh

#!/bin/bash
set -ex

# Inject APM Trace ID (part of SQL query comment) to a Log event
# https://docs.datadoghq.com/tracing/advanced/connect_logs_and_traces/?tab=ruby
# Input: {"command": "Query", "current_statement": "SELECT ... /* 4572859165692197980 */"}
# Output: {"process_list": {"current_statement": "SELECT ... /* 4572859165692197980 */"}, "dd": {"trace_id": 4572859165692197980}}
function inject_trace_id() {
  trace_id=$(echo "$1" |grep -Eo '/\* [0-9]{16,20} \*/' | awk '{print $2}')

  if [ -z "$trace_id" ]
  then
    echo "{\"process_list\": $1}" 
  else
    echo "{\"process_list\": $1, \"dd\": {\"trace_id\": ${trace_id}}}"
  fi
}


# Process List poll to JSON format, duration transform to millisecond unit
# Output multiline: {"command": "Query", "current_statement": "SELECT ... /* 4572859165692197980 */"}
function process_list() {
    /usr/bin/mysql -h127.0.0.1 -uroot -p111111 -P6033 -s -r -e "SELECT 
    JSON_OBJECT(
      'thd_id', thd_id,
      'conn_id', conn_id,
      'command', command,
      'state', state,
      'current_statement', current_statement,
      'statement_latency', statement_latency / 1000,
      'progress', progress,
      'lock_latency', lock_latency / 1000,
      'rows_examined', rows_examined, 
      'rows_sent', rows_sent,
      'rows_affected', rows_affected,
      'tmp_tables', tmp_tables, 
      'tmp_disk_tables', tmp_disk_tables,
      'full_scan', full_scan,
      'last_statement', last_statement,
      'last_statement_latency', last_statement_latency / 1000
    )
    FROM sys.x\$processlist 
    WHERE pid IS NOT NULL 
    AND db != 'sys';"
  }


# Read process list output line by line and redirect to STDOUT twice a second, STDOUT -> Datadog Logs
while true; do
  process_list | while read -r item; do
    inject_trace_id "$item" > /proc/1/fd/1
  done
  sleep 0.5;
done

# MIT License

MIT License

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.