Sudoers templates for elevation in UNIX/Linux monitoring

Effective monitoring of UNIX or Linux operating systems requires some elevated permissions on the client system for both monitoring and maintenance tasks. There are sudoers configuration templates provided in this article for baseline operability.

Introduction

In order to use sudo-enabled accounts for monitoring with Operations Manager, configurations must be put into place to authorize elevation for RunAs Accounts using sudo. General requirements for the accounts used by Operations Manager with sudo elevation are:

• The accounts must have RequireTTY disabled as a default parameter.
• The accounts must be configured to elevate with NOPASSWD.
• The accounts must have the "lecture" that typically is shown when logging in, and when elevating using sudo, disabled.

The provided templates specify the commands that allow the configured RunAs Accounts to execute tasks that require elevated permissions such as:

• Installing the agent
• Upgrading the agent
• Uninstalling the agent
• Monitoring system logs
• Restarting the agent services
• Facilitating the creation of authentication certificates

Note

Commands and requirements are not the same across all UNIX/Linux distributions or versions, ensure you have the correct template for your Operating System.

Don't see your OS? Refer to the Supported UNIX and Linux operating system versions page for supported distributions.

Using the templates

Select the appropriate template for your Operating System and replace the example accounts with your RunAs Account usernames, include are other organizational customizations if necessary.

In each template there are two accounts defined and maps to standard RunAs Accounts as:

RunAs Account	Username
UNIX/Linux Action Account	scomuser
UNIX/Linux Maintenance Account	scomadm

Once updated with the correct usernames and any extra modifications, the template must be added to the client system's sudoers configuration. There are typically two ways to add sudo configurations, either by directly modifying the /etc/sudoers or /etc/sudo.conf file (depending on the OS), or by adding a "drop in" file under /etc/sudoers.d (ex. /etc/sudoers.d/scom). This article doesn't go into detail on how to fully configure sudo itself. For more information, see the documentation provided by the vendor for your specific operating system.

Red Hat Enterprise Linux (RHEL)

Important

Beginning with version 8, Red Hat Enterprise Linux falls under Universal Linux.

RHEL 7

#-----------------------------------------------------------------------------------
# Example user configuration for Operations Manager 2022
# Example assumes users named: scomadm & scomuser
# Replace usernames & corresponding /tmp/scx-\<username\> specification for your environment

# General requirements
Defaults:scomadm !requiretty

# Agent maintenance
## Certificate signing
scomadm ALL=(root) NOPASSWD: /bin/sh -c cp /tmp/scx-scomadm/scx.pem /etc/opt/microsoft/scx/ssl/scx.pem; rm -rf /tmp/scx-scomadm; /opt/microsoft/scx/bin/tools/scxadmin -restart
scomadm ALL=(root) NOPASSWD: /bin/sh -c cat /etc/opt/microsoft/scx/ssl/scx.pem
scomadm ALL=(root) NOPASSWD: /usr/bin/sh -c if test -f /opt/microsoft/omsagent/bin/service_control; then cp /tmp/scx-scomadm/omsadmin.conf /etc/opt/microsoft/omsagent/scom/conf/omsadmin.conf; /opt/microsoft/omsagent/bin/service_control restart scom; fi

## Install or upgrade
# Compiler mitigated agent version changes
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].rhel.[[\:digit\:]].s.x[6-8][4-6].sh --install --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9][0-9]-[0-9].rhel.[[\:digit\:]].x[6-8][4-6].sh --install --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].rhel.[[\:digit\:]].x[6-8][4-6].sh --install --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].rhel.[[\:digit\:]].s.x[6-8][4-6].sh --upgrade --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9][0-9]-[0-9].rhel.[[\:digit\:]].x[6-8][4-6].sh --upgrade --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].rhel.[[\:digit\:]].x[6-8][4-6].sh --upgrade --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC

## Uninstall
#scomadm ALL=(root) NOPASSWD: /bin/sh -c /opt/microsoft/scx/bin/uninstall
scomadm ALL=(root) NOPASSWD: /bin/sh -c if test -f /opt/microsoft/omsagent/bin/omsadmin.sh; then if test "$(/opt/microsoft/omsagent/bin/omsadmin.sh -l | grep scom | wc -l)" \= "1" && test "$(/opt/microsoft/omsagent/bin/omsadmin.sh -l | wc -l)" \= "1" || test "$(/opt/microsoft/omsagent/bin/omsadmin.sh -l)" \= "No Workspace"; then /opt/microsoft/omsagent/bin/uninstall; else /opt/microsoft/omsagent/bin/omsadmin.sh -x scom; fi; else /opt/microsoft/scx/bin/uninstall; fi

## Log file monitoring
scomuser ALL=(root) NOPASSWD: /opt/microsoft/scx/bin/scxlogfilereader -p

### Examples ###
## Custom shell command monitoring example – replace \<shell command\> with the correct command string
#scomuser ALL=(root) NOPASSWD: /bin/sh -c echo error

## Daemon diagnostic and restart recovery tasks example (using cron)
#scomuser ALL=(root) NOPASSWD: /bin/sh -c ps -ef | grep cron | grep -v grep
#scomuser ALL=(root) NOPASSWD: /usr/sbin/cron & 

# End user configuration for Operations Manager agent
#-----------------------------------------------------------------------------------

SUSE Linux Enterprise Server (SLES)

Important

Starting with version 15, SUSE falls under Universal Linux.

SLES 12

#-----------------------------------------------------------------------------------
# Example user configuration for Operations Manager 2022
# Example assumes users named: scomadm & scomuser
# Replace usernames & corresponding /tmp/scx-\<username\> specification for your environment

# General requirements
Defaults:scomadm !requiretty

# Agent maintenance
## Certificate signing
scomadm ALL=(root) NOPASSWD: /bin/sh -c cp /tmp/scx-scomadm/scx.pem /etc/opt/microsoft/scx/ssl/scx.pem; rm -rf /tmp/scx-scomadm; /opt/microsoft/scx/bin/tools/scxadmin -restart
scomadm ALL=(root) NOPASSWD: /bin/sh -c cat /etc/opt/microsoft/scx/ssl/scx.pem
scomadm ALL=(root) NOPASSWD: /bin/sh -c if test -f /opt/microsoft/omsagent/bin/service_control; then cp /tmp/scx-scomadm/omsadmin.conf /etc/opt/microsoft/omsagent/scom/conf/omsadmin.conf; /opt/microsoft/omsagent/bin/service_control restart scom; fi

## Install or upgrade
# Compiler mitigated agent version changes
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].sles.1[[\:digit\:]].s.x[6-8][4-6].sh --install --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9][0-9]-[0-9].sles.1[[\:digit\:]].x[6-8][4-6].sh --install --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].sles.1[[\:digit\:]].x[6-8][4-6].sh --install --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].sles.1[[\:digit\:]].s.x[6-8][4-6].sh --upgrade --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9][0-9]-[0-9].sles.1[[\:digit\:]].x[6-8][4-6].sh --upgrade --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].sles.1[[\:digit\:]].x[6-8][4-6].sh --upgrade --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC

## Uninstall
#scomadm ALL=(root) NOPASSWD: /bin/sh -c /opt/microsoft/scx/bin/uninstall
scomadm ALL=(root) NOPASSWD: /bin/sh -c if test -f /opt/microsoft/omsagent/bin/omsadmin.sh; then if test "$(/opt/microsoft/omsagent/bin/omsadmin.sh -l | grep scom | wc -l)" \= "1" && test "$(/opt/microsoft/omsagent/bin/omsadmin.sh -l | wc -l)" \= "1" || test "$(/opt/microsoft/omsagent/bin/omsadmin.sh -l)" \= "No Workspace"; then /opt/microsoft/omsagent/bin/uninstall; else /opt/microsoft/omsagent/bin/omsadmin.sh -x scom; fi; else /opt/microsoft/scx/bin/uninstall; fi

## Log file monitoring
scomuser ALL=(root) NOPASSWD: /opt/microsoft/scx/bin/scxlogfilereader -p

### Examples ###
## Custom shell command monitoring example – replace \<shell command\> with the correct command string
#scomuser ALL=(root) NOPASSWD: /bin/sh -c echo error

## Daemon diagnostic and restart recovery tasks example (using cron)
#scomuser ALL=(root) NOPASSWD: /bin/sh -c ps -ef | grep cron | grep -v grep
#scomuser ALL=(root) NOPASSWD: /usr/sbin/cron & 

# End user configuration for Operations Manager agent
#-----------------------------------------------------------------------------------

Universal Linux

Universal Linux encompasses both Debian and Red Hat based operating systems and is where to find the latest supported Linux operating systems and distributions. For a list of distros that fall under this class type, refer to: Supported UNIX and Linux Operating System Versions

#----------------------------------------------------------------------------------------
# Example user configuration for Operations Manager 2022
# Example assumes users named: scomadm & scomuser
# Replace usernames & corresponding /tmp/scx-\<username\> specification for your environment

# General requirements
Defaults:scomadm !requiretty

# Agent maintenance
## Certificate signing
scomadm ALL=(root) NOPASSWD: /bin/sh -c cp /tmp/scx-scomadm/scx.pem /etc/opt/microsoft/scx/ssl/scx.pem; rm -rf /tmp/scx-scomadm; /opt/microsoft/scx/bin/tools/scxadmin -restart
scomadm ALL=(root) NOPASSWD: /bin/sh -c cat /etc/opt/microsoft/scx/ssl/scx.pem
scomadm ALL=(root) NOPASSWD: /bin/sh -c if test -f /opt/microsoft/omsagent/bin/service_control; then cp /tmp/scx-scomadm/omsadmin.conf /etc/opt/microsoft/omsagent/scom/conf/omsadmin.conf; /opt/microsoft/omsagent/bin/service_control restart scom; fi

## Install or upgrade
# Compiler mitigated agent version changes
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].universal[[\:alpha\:]].[[\:digit\:]].s.x[6-8][4-6].sh --install --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9]-[0-9].universal[[\:alpha\:]].[[\:digit\:]].x[6-8][4-6].sh --install --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].universal[[\:alpha\:]].[[\:digit\:]].x[6-8][4-6].sh --install --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].universal[[\:alpha\:]].[[\:digit\:]].s.x[6-8][4-6].sh --upgrade --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9]-[0-9].universal[[\:alpha\:]].[[\:digit\:]].x[6-8][4-6].sh --upgrade --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC
scomadm ALL=(root) NOPASSWD: /bin/sh -c sh /tmp/scx-scomadm/scx-1.[5-9].[0-9]-[0-9].universal[[\:alpha\:]].[[\:digit\:]].x[6-8][4-6].sh --upgrade --enable-opsmgr; EC=$?; cd /tmp; rm -rf /tmp/scx-scomadm; exit $EC

## Uninstall
#scomadm ALL=(root) NOPASSWD: /bin/sh -c /opt/microsoft/scx/bin/uninstall
scomadm ALL=(root) NOPASSWD: /bin/sh -c if test -f /opt/microsoft/omsagent/bin/omsadmin.sh; then if test "$(/opt/microsoft/omsagent/bin/omsadmin.sh -l | grep scom | wc -l)" \= "1" && test "$(/opt/microsoft/omsagent/bin/omsadmin.sh -l | wc -l)" \= "1" || test "$(/opt/microsoft/omsagent/bin/omsadmin.sh -l)" \= "No Workspace"; then /opt/microsoft/omsagent/bin/uninstall; else /opt/microsoft/omsagent/bin/omsadmin.sh -x scom; fi; else /opt/microsoft/scx/bin/uninstall; fi

## Log file monitoring
scomuser ALL=(root) NOPASSWD: /opt/microsoft/scx/bin/scxlogfilereader -p

### Examples ###
## Custom shell command monitoring example – replace \<shell command\> with the correct command string
#scomuser ALL=(root) NOPASSWD: /bin/sh -c echo error

## For ubuntu18
#scomuser ALL=(root) NOPASSWD: /bin/bash -c echo error

## Daemon diagnostic and restart recovery tasks example (using cron)
#scomuser ALL=(root) NOPASSWD: /bin/sh -c ps -ef | grep cron | grep -v grep
#scomuser ALL=(root) NOPASSWD: /usr/sbin/cron & 

# End user configuration for Operations Manager 
#-----------------------------------------------------------------------------------

Other commands

When using the ExecuteShellScript method to run elevated scripts, add the following line your sudoers file for your user:

scomuser ALL=(root) NOPASSWD: /etc/opt/microsoft/scx/conf/tmpdir/scx*

This line is required as the ExecuteShellScript method copies the contents of the elevated script to a temporary file with a randomly generated filename in tmpdir and execute it from there.

When using the ExecuteShellCommand method to run elevated commands, add something like this in your sudoers file:

• /bin/sh is the default shell of the user running the command, and (in this example).
• /usr/bin/vmstat -c is the command you want to run.

scomuser ALL=(root) NOPASSWD: /bin/sh -c /usr/bin/vmstat -c

There should be no quotes around the command as only the shell recognizes them, sudo doesn't.

Troubleshooting

Sudo error log

One of the best ways to troubleshoot authentication failures related to sudoers configurations can be to inspect the sudo log on the agent host.

• For RedHat based operating systems, the default log location is /var/log/secure.
• For Debian based operating systems, the default log location is /var/log/auth.log.

Check the /etc/sudoers file for the logfile parameter to see where the log is currently being written to if using a different operating system or customized log location.

Password prompts and timeouts

By default, sudo prompts for a password if a command isn't configured with NOPASSWD for the user, there's no functionality to automatically input passwords when prompted like this, and breaks monitoring. To prevent extended issues if NOPASSWD isn't configured for a command, the recommendation is to configure the following option in sudoers for the user account:

Defaults:scomuser passwd_tries = 1, passwd_timeout = 1

This example sets a one-minute password prompt timeout for the user scomuser, which allows the command to fail quickly if a sudo configuration problem exists.

Password errors or other authentication failures

For guidelines on password and authentication configurations, see Planning Security Credentials for Accessing UNIX and Linux Computers.