Cray System Management Documentation > Install CSM > Create HMN Connections JSON File

Create HMN Connections JSON File

Use this procedure to generate the hmn_connections.json from the system’s SHCD Excel document. This process is typically needed when generating the hmn_connections.json file for a new system, or regenerating it when a system’s SHCD file is changed (specifically the HMN tab). The hms-shcd-parser tool can be used to generate the hmn_connections.json file.

The SHCD/HMN Connections Rules document explains the expected naming conventions and rules for the HMN tab of the SHCD file, and for the hmn_connections.json file.

Prerequisites

SHCD Excel file for the system
Podman is available

Podman is available on the CSM LiveCD, and is installed onto an NCN when being used as an environment to create the CSM PIT in the Bootstrap PIT Node from LiveCD USB or Bootstrap Pit Node from LiveCD Remote ISO procedures.

Procedure

Inspect the HMN tab of the SHCD file.

Verify that it does not have unexpected data in columns J through U in rows 20 or below. If any unexpected data is present in this region of the HMN tab, then it will end up in the generated hmn_connections.json. Therefore, it must be removed before generating the hmn_connections.json file. Unexpected data is anything other than HMN cabling information, such as another table placed below the HMN cabling information. Any data above row 20 will not interfere when generating hmn_connections.json.

For example, the following image shows an unexpected table present underneath HMN cabling information in rows 26 to 29. The HMN cabling information was truncated in this example for brevity.
Load the hms-shcd-parser container image from the CSM release distribution into Podman.

The CSM_RELEASE environment variable is expected to to be set from the Bootstrap PIT Node from LiveCD USB or Bootstrap Pit Node from LiveCD Remote ISO procedures.

It is expected that the current directory contains the directory of the extracted CSM release tarball.

Determine the version of the hms-shcd-parser container image:
```
linux# SHCD_PARSER_VERSION=$(realpath ./${CSM_RELEASE}/docker/dtr.dev.cray.com/cray/hms-shcd-parser* | egrep  -o '[0-9]+\.[0-9]+\.[0-9]+$')
linux# echo $SHCD_PARSER_VERSION
```
Load the hms-shcd-parser container image into Podman:
```
linux# ./${CSM_RELEASE}/hack/load-container-image.sh dtr.dev.cray.com/cray/hms-shcd-parser:$SHCD_PARSER_VERSION
```
Copy the system’s SHCD file to the machine being used to prepare the hmn_connections.json file.
Set a variable to point to the system’s SHCD Excel file.

NOTE: Make sure to quote the SHCD file path if there is whitespace in the document’s path or filename.
```
linux# SHCD_FILE="/path/to/systems/SHCD.xlsx"
```

Generate the hmn_connections.json file from the SHCD file.

This will create the hmn_connections.json file in the current directory. If it already exists, it will be overwritten.

linux# podman run --rm -it --name hms-shcd-parser -v "$(realpath "$SHCD_FILE")":/input/shcd_file.xlsx -v "$(pwd)":/output dtr.dev.cray.com/cray/hms-shcd-parser:$SHCD_PARSER_VERSION