A series of Slurm SPANK plugin examples to help people new to writing them. Hopefully it will help understand, and maybe dare I say inspire.
The only things required to build the plugin is GCC and the spank.h header file. The header file can be located in the slurm-devel package.
Assuming the source code is demo.c. To compile run ...
gcc -fPIC -shared -o demo.so demo.cThis should generate a shared object called demo.so containing all your hard work. This now needs to be copied onto each compute and login node into the desired location as specified in the plugstack.conf file.
optional <PATH>/demo.soIf you don't specify the full path then the PluginDir in slurm.conf will be searched.
Note: Alternatively, you can create a plugstack.conf.d directory and point to it via an include statement in the plugstack.conf. Then copy the supplied demo.conf examples into the plugstack.conf.d directory.
Rather than using the 'optional' argument you can specify 'required'. I tend to use 'optional' when developing a plugin, as the 'required' argument will place the node into a drain state should a function within the plugin fail - while this sounds bad it can be helpful if you are using the SPANK plugin to perform node checks.
Examples in src/plugins/ include ...
| Plugin | Description |
|---|---|
| demo.c | Basic plugin that reads job environment variables and prints them to Slurmd's log. |
| entrypoints.c | Trace each entrypoint. |
| envs.c | Similar to demo.c but also prints out the job name. |
| execute.c | Execute a command within the same control group as the job step, and terminate the command when the job step ends. |
| options.c | Register and parse two options (opt1 and opt2). Option opt1 is set as environment variable. Option opt2 is compared against a global runtime argument, see corresponding plugstack.conf.d/options.conf. |
| preload.c | Set LD_PRELOAD for job. Expects preloader.so to be in /tmp/, see src/preload/preloader.c for the source. |
Corresponding plugstack configuration files can be found in plugstack.conf.d/