> >

Configure Pluggable Authentication Modules (PAM) on UANs

Perform this procedure to configure PAM on UANs. This enables dynamic authentication support for system services.

Intialize and configure the Cray command line interface (CLI) tool on the system. See “Configure the Cray Command Line Interface (CLI)” in the CSM documentation for more information.

Verify that the Gitea Version Control Service (VCS) is running.

ncn-m001# kubectl get pods --all-namespaces | grep vcs
services          gitea-vcs-f57c54c4f-j8k4t          2/2     Running             1          11d
services          gitea-vcs-postgres-0               2/2     Running             0          11d

Retrieve the initial Gitea login credentials for the crayvcs username.
```
ncn-m001# kubectl get secret -n services vcs-user-credentials \
 --template={{.data.vcs_password}} | base64 --decode
```
These credentials can be modified in the vcs_user role prior to installation or can be modified after logging in.
Use an external web browser to verify the Ansible plays are available on the system.

The URL will take on the following format:

https://api.SYSTEM-NAME.DOMAIN-NAME/vcs

Clone the system Version Control Service (VCS) repository to a directory on the system.

ncn-w001# git clone https://api-gw-service-nmn.local/vcs/cray/uan-config-management.git

Change to the uan-config-management directory.
```
ncn-w001# cd uan-config-management
```
Make a new directory for the PAM configuration.

a. Create a group_vars/all directory if making changes to all UANs.
```
ncn-w001# mkdir -p group_vars/all
ncn-w001# cd group_vars/all
```
b. Create a host_vars/XNAME directory if the change is node specific.
```
ncn-w001# mkdir -p host_vars/XNAME
ncn-w001# cd host_vars/XNAME
```

Configure PAM.

The default path is /etc/pam.d/, so only the module file name is required.

# vi pam.yml
---
uan_pam_modules:
  - name: pam_module_file_name
    lines:
      - "add this line to pam module file_name" 
      - "add another line to pam module file_name"  
  - name: another_pam_module_file_name    
    lines:    
      - "add this line to another_pam_module_file_name"

The following is an example of adding the line "account required pam\_access.so" to the /etc/pam.d/common-account PAM file. The \t is used to place a tab between account required and pam\_access.so to match the formatting of the common-account file contents. The quotes are required in the strings used in the lines filed.

---
uan_pam_modules:
  - name: common-account
    lines:
      - "account required\tpam_access.so"

Add the change from the working directory to the staging area.

All UANs:

ncn-w001# git add group_vars/all/pam.yml

Node specific:

ncn-w001# git add host_vars/XNAME/pam.yml

Commit the file to the master branch.

ncn-w001# git commit -am 'Added PAM configuration'

Push the commit.
```
ncn-w001# git push
```
If prompted, use the Gitea login credentials.

Reboot the UAN(s) with the Boot Orchestration Service (BOS).

ncn-w001# cray bos session create \
 --template-uuid UAN_SESSION_TEMPLATE --operation reboot