2.5.5. Starting an Agent with a Custom Command

When configuring the agent to run as a service in Section 2.5.4, “Running the Agent as a Daemon or init.d Service”, the agent can be configured to start with a custom start command. This is used mainly to start the agent using su or sudo, allowing the agent to run as a different user.

The start command is defined with the other agent properties in the rhq-agent-env.sh file. There are two parts to the configuration: the start command itself and then a setting to enable a password prompt.

RHQ_AGENT_START_COMMAND="su -m test -c '${RHQ_AGENT_HOME}/bin/rhq-agent.sh'"
RHQ_AGENT_PASSWORD_PROMPT=true

RHQ_AGENT_START_COMMAND="su -m test -c '${RHQ_AGENT_HOME}/bin/rhq-agent.sh'"
RHQ_AGENT_PASSWORD_PROMPT=true

Setting a start command overrides whatever command is passed in the command line to start the agent.

The password prompt may not be required; it depends on the sudo and agent user configuration. If it is required, then the password prompt should be enabled so that the user can enter the password or a password should be set in the RHQ_AGENT_PASSWORD parameter; otherwise, the start process will appear to hang.

If the defined start command is invalid, then the agent can fail to start. Along with the command formatting, the directory name can be affected; if there are spaces or special characters in the name, those must be escaped for the command to run.