Add ClearML Agent Slurm Glue info (#736)

docs/clearml_agent.md

@@ -327,6 +327,112 @@ There are two options for deploying the ClearML Agent to a Kubernetes cluster:
 
 For more details, see [Kubernetes integration](https://github.com/allegroai/clearml-agent#kubernetes-integration-optional).
 
+### Slurm
+
+:::important Enterprise Feature
+Slurm Glue is available under the ClearML Enterprise plan
+:::
+
+Agents can be deployed bare-metal or inside [`Singularity`](https://docs.sylabs.io/guides/3.5/user-guide/introduction.html) 
+containers in linux clusters managed with Slurm. 
+
+ClearML Agent Slurm Glue maps jobs to Slurm batch scripts: associate a ClearML queue to a batch script template, then 
+when a Task is pushed into the queue, it will be converted and executed as an `sbatch` job according to the sbatch 
+template specification attached to the queue. 
+
+1. Install the Slurm Glue on a machine where you can run `sbatch` / `squeue` etc. 
+   
+   ```
+   pip3 install -U --extra-index-url https://*****@*****.allegro.ai/repository/clearml_agent_slurm/simple clearml-agent-slurm
+   ```
+
+1. Create a new batch template. Make sure to set the `SBATCH` variables to the resources you want to attach to the queue. 
+   The script below sets up an agent to run bare-metal, creating a virtual environment per job. For example:
+
+   ```
+   #!/bin/bash
+   # available template variables (default value separator ":")
+   # ${CLEARML_QUEUE_NAME}
+   # ${CLEARML_QUEUE_ID}
+   # ${CLEARML_WORKER_ID}.
+   # complex template variables  (default value separator ":")
+   # ${CLEARML_TASK.id}
+   # ${CLEARML_TASK.name}
+   # ${CLEARML_TASK.project.id}
+   # ${CLEARML_TASK.hyperparams.properties.user_key.value}
+   
+   
+   # example
+   #SBATCH --job-name=clearml_task_${CLEARML_TASK.id}       # Job name DO NOT CHANGE
+   #SBATCH --ntasks=1                    # Run on a single CPU
+   # #SBATCH --mem=1mb                   # Job memory request
+   # #SBATCH --time=00:05:00             # Time limit hrs:min:sec
+   #SBATCH --output=task-${CLEARML_TASK.id}-%j.log
+   #SBATCH --partition debug
+   #SBATCH --cpus-per-task=1
+   #SBATCH --priority=5
+   #SBATCH --nodes=${CLEARML_TASK.hyperparams.properties.num_nodes.value:1}
+   
+   
+   ${CLEARML_PRE_SETUP}
+   
+   echo whoami $(whoami)
+   
+   ${CLEARML_AGENT_EXECUTE}
+   
+   ${CLEARML_POST_SETUP}
+   ```
+
+   Notice: If you are using Slurm with Singularity container support replace `${CLEARML_AGENT_EXECUTE}` in the batch 
+   template with `singularity exec ${CLEARML_AGENT_EXECUTE}`. For additional required settings, see [Slurm with Singularity](#slurm-with-singularity).
+
+   :::tip 
+   You can override the default values of a Slurm job template via the ClearML Web UI. The following command in the 
+   template sets the `nodes` value to be the ClearML Task’s `num_nodes` user property:  
+   ```
+   #SBATCH --nodes=${CLEARML_TASK.hyperparams.properties.num_nodes.value:1}
+   ```
+   This user property can be modified in the UI, in the task's **CONFIGURATION > User Properties** section, and when the 
+   task is executed the new modified value will be used. 
+   ::: 
+
+3. Launch the ClearML Agent Slurm Glue and assign the Slurm configuration to a ClearML queue. For example, the following 
+   associates the `default` queue to the `slurm.example.template` script, so any jobs pushed to this queue will use the 
+   resources set by that script.  
+   ```
+   clearml-agent-slurm --template-files slurm.example.template --queue default
+   ```
+   
+   You can also pass multiple templates and queues. For example:
+   ```
+   clearml-agent-slurm --template-files slurm.template1 slurm.template2 --queue queue1 queue2
+   ```
+
+#### Slurm with Singularity
+If you are running Slurm with Singularity containers support, set the following:
+
+1. Make sure your `sbatch` template contains:
+   ```
+   singularity exec ${CLEARML_AGENT_EXECUTE}
+   ```
+   Additional singularity arguments can be added, for example: 
+   ```
+   singularity exec --uts ${CLEARML_AGENT_EXECUTE}`
+   ``` 
+1. Set the default Singularity container to use in your [clearml.conf](configs/clearml_conf.md) file:
+   ```
+   agent.default_docker.image="shub://repo/hello-world"
+   ```
+   Or
+   ```
+   agent.default_docker.image="docker://ubuntu"
+   ```
+
+1. Add `--singularity-mode` to the command line, for example:
+   ```
+   clearml-agent-slurm --container-mode --template-files slurm.example_singularity.template --queue default
+   ```
+
 ### Explicit Task Execution
 
 ClearML Agent can also execute specific tasks directly, without listening to a queue.