futoase/docker-mysql-debug

MySQL Debug Build Docker Image

This Dockerfile builds MySQL database server with debugging information.

Please do not use this image in production envrionment because mysqld is compiled without optimization (-O0 option).

How to Build

MySQL 5.7

$ docker build -t mysql-debug-5.7 5.7

MySQL 5.6

$ docker build -t mysql-debug-5.6 5.6

How To Remote Debug on MacOS

Install GDB which recognizes GNU/Linux ABI.

You need to install GDB which recognizes GNU/Linux ABI. You can install GDB with the following step.

$ brew tap homebrew/dupes
$ brew install gdb --with-all-target

You can confirm supported ABIs with set osabi command.

$ gdb
(gdb) set osabi
Requires an argument. Valid arguments are auto, default, none, GNU/Linux, Symbian, NetBSD/a.out, NetBSD/ELF, OpenBSD/ELF, WindowsCE, Cygwin, FreeBSD/a.out, FreeBSD/ELF, GNU/Hurd, QNX-Neutrino, Solaris, SVR4, DJGPP, DICOS, Darwin, SDE, AIX, LynxOS178, Newlib, OpenVMS.
(gdb) q

Docker run

$ mkdir -p ~/src
$ cd ~/src
$ wget http://ftp.jaist.ac.jp/pub/mysql/Downloads/MySQL-5.7/mysql-boost-5.7.19.tar.gz
$ tar zxf mysql-boost-5.7.19.tar.gz
$ docker run -v ~/src/mysql-5.7.19:/mysql-debug/mysql-5.7.19 -p 3306:3306 -p 2345:2345 -t --cap-add=SYS_PTRACE --security-opt seccomp=unconfined mysql-debug-5.7 /bin/bash -c 'cd /mysql-debug; cp /mysql-debug/bin/mysqld /mysql-debug/mysql-5.7.19; sudo gdbserver :2345 ./bin/mysqld --user=root'

Remote debug with GDB

The following example is to trace ALTER TABLE statement.

Load symbols
Set source code path to ~/src/mysql-5.7.19
Set breakpoint
Attach the mysqld process remotely

$ gdb
(gdb) file ~/src/mysql-5.7.19/mysqld
Reading symbols from ~/src/mysql-5.7.19/mysqld...done.
(gdb) set substitute-path /mysql-debug/mysql-5.7.19 ~/src/mysql-5.7.19
(gdb) b mysql_alter_table
Breakpoint 1 at 0x15d88c8: file /mysql-debug/mysql-5.7.19/sql/sql_table.cc, line 8955.
(gdb) target remote :2345
Remote debugging using :2345
Reading /lib64/ld-linux-x86-64.so.2 from remote target...
...
(gdb) c
Continuing.
...

Thread 3 hit Breakpoint 1, mysql_alter_table (thd=0x7fffb4289b20, 
    new_db=0x7fffb4044c38 "hoge", new_name=0x0, 
    create_info=0x7fffec4b6530, table_list=0x7fffb40446b0, 
    alter_info=0x7fffec4b6480)
    at /mysql-debug/mysql-5.7.19/sql/sql_table.cc:8955
8955	/mysql-debug/mysql-5.7.19/sql/sql_table.cc: No such file or directory.
(gdb) bt
#0  mysql_alter_table (thd=0x7fffb4289b20, new_db=0x7fffb4044c38 "hoge", 
    new_name=0x0, create_info=0x7fffec4b6530, table_list=0x7fffb40446b0, 
    alter_info=0x7fffec4b6480)
    at /mysql-debug/mysql-5.7.19/sql/sql_table.cc:8955
    ...

mysql command on MacOS

To connect to the MySQL server, you can connect to 127.0.0.1:3306 with the mysql command.

$ mysql -h 127.0.0.1 -uroot
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.19-debug Source distribution
...
mysql>

futoase / docker-mysql-debug