From e2b0b25a7dfd9c6b61cb036cf6021fecafe4787e Mon Sep 17 00:00:00 2001
From: Nichamon Naksinehaboon <nichamon@opengridcomputing.com>
Date: Wed, 21 Feb 2024 13:21:30 -0600
Subject: [PATCH] Add pid_file configuration command

The `pid_file` configuration command is an alternative approach to set
the PID file path in configuration file to the `-r` command-line option.
---
 ldms/src/ldmsd/ldmsd_request.c      | 31 +++++++++++++++++++++++++++++
 ldms/src/ldmsd/ldmsd_request.h      |  1 +
 ldms/src/ldmsd/ldmsd_request_util.c |  1 +
 3 files changed, 33 insertions(+)

diff --git a/ldms/src/ldmsd/ldmsd_request.c b/ldms/src/ldmsd/ldmsd_request.c
index fe26be957..654a10df2 100644
--- a/ldms/src/ldmsd/ldmsd_request.c
+++ b/ldms/src/ldmsd/ldmsd_request.c
@@ -312,6 +312,7 @@ static int publish_kernel_handler(ldmsd_req_ctxt_t reqc);
 static int daemon_name_set_handler(ldmsd_req_ctxt_t reqc);
 static int worker_threads_set_handler(ldmsd_req_ctxt_t reqc);
 static int default_credits_set_handler(ldmsd_req_ctxt_t reqc);
+static int pid_file_handler(ldmsd_req_ctxt_t reqc);
 
 /* executable for all */
 #define XALL 0111
@@ -679,6 +680,9 @@ static struct request_handler_entry request_handler[] = {
 	[LDMSD_DEFAULT_CREDITS_REQ] = {
 		LDMSD_DEFAULT_CREDITS_REQ, default_credits_set_handler, XUG
 	},
+	[LDMSD_PID_FILE_REQ] = {
+		LDMSD_PID_FILE_REQ, pid_file_handler, XUG
+	},
 };
 
 int is_req_id_priority(enum ldmsd_request req_id)
@@ -697,6 +701,7 @@ int is_req_id_priority(enum ldmsd_request req_id)
 	case LDMSD_DAEMON_NAME_SET_REQ:
 	case LDMSD_WORKER_THR_SET_REQ:
 	case LDMSD_DEFAULT_CREDITS_REQ:
+	case LDMSD_PID_FILE_REQ:
 		return 1;
 	default:
 		return 0;
@@ -9267,3 +9272,29 @@ static int default_credits_set_handler(ldmsd_req_ctxt_t reqc)
 	free(value);
 	return rc;
 }
+
+static int pid_file_handler(ldmsd_req_ctxt_t reqc)
+{
+	int rc = 0;
+	char *path = NULL;
+
+	path = ldmsd_req_attr_str_value_get_by_id(reqc, LDMSD_ATTR_PATH);
+	if (!path) {
+		reqc->errcode = EINVAL;
+		reqc->line_off = snprintf(reqc->line_buf, reqc->line_len,
+					  "The attribute 'path' is missing.");
+		goto send_reply;
+	}
+
+	reqc->errcode = ldmsd_process_cmd_line_arg('r', path);
+	if (reqc->errcode) {
+		reqc->line_off = snprintf(reqc->line_buf, reqc->line_len,
+					  "Failed to open the log file '%s'.", path);
+		goto send_reply;
+	}
+
+send_reply:
+	ldmsd_send_req_response(reqc, reqc->line_buf);
+	free(path);
+	return rc;
+}
diff --git a/ldms/src/ldmsd/ldmsd_request.h b/ldms/src/ldmsd/ldmsd_request.h
index 6e85dcc9c..047ef1c79 100644
--- a/ldms/src/ldmsd/ldmsd_request.h
+++ b/ldms/src/ldmsd/ldmsd_request.h
@@ -153,6 +153,7 @@ enum ldmsd_request {
 	LDMSD_DAEMON_NAME_SET_REQ,
 	LDMSD_WORKER_THR_SET_REQ,
 	LDMSD_DEFAULT_CREDITS_REQ,
+	LDMSD_PID_FILE_REQ,
 
 	/* failover requests by user */
 	LDMSD_FAILOVER_CONFIG_REQ = 0x700, /* "failover_config" user command */
diff --git a/ldms/src/ldmsd/ldmsd_request_util.c b/ldms/src/ldmsd/ldmsd_request_util.c
index 9966c4843..4d779f449 100644
--- a/ldms/src/ldmsd/ldmsd_request_util.c
+++ b/ldms/src/ldmsd/ldmsd_request_util.c
@@ -98,6 +98,7 @@ const struct req_str_id req_str_id_table[] = {
 	{  "metric_sets_default_authz", LDMSD_SET_DEFAULT_AUTHZ_REQ  },
 	{  "oneshot",            LDMSD_ONESHOT_REQ  },
 	{  "option",             LDMSD_CMDLINE_OPTIONS_SET_REQ  },
+	{  "pid_file",           LDMSD_PID_FILE_REQ  },
 	{  "plugn_sets",         LDMSD_PLUGN_SETS_REQ  },
 	{  "plugn_status",       LDMSD_PLUGN_STATUS_REQ  },
 	{  "prdcr_add",          LDMSD_PRDCR_ADD_REQ  },