Split command execution functions into separate library

These may need to be executed by repmgrd.
2026-03-22 22:56:29 +00:00 · 2019-02-27 14:40:08 +09:00
parent 5c2264eb8d
commit b1875a8d91
8 changed files with 219 additions and 149 deletions
--- a/sysutils.c
+++ b/sysutils.c
@@ -0,0 +1,178 @@
+/*
+ * sysutils.c
+ *
+ * Copyright (c) 2ndQuadrant, 2010-2019
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "repmgr.h"
+
+static bool _local_command(const char *command, PQExpBufferData *outputbuf, bool simple, int *return_value);
+
+
+/*
+ * Execute a command locally. "outputbuf" should either be an
+ * initialised PQexpbuffer, or NULL
+ */
+bool
+local_command(const char *command, PQExpBufferData *outputbuf)
+{
+	return _local_command(command, outputbuf, false, NULL);
+}
+
+bool
+local_command_return_value(const char *command, PQExpBufferData *outputbuf, int *return_value)
+{
+	return _local_command(command, outputbuf, false, return_value);
+}
+
+
+bool
+local_command_simple(const char *command, PQExpBufferData *outputbuf)
+{
+	return _local_command(command, outputbuf, true, NULL);
+}
+
+
+static bool
+_local_command(const char *command, PQExpBufferData *outputbuf, bool simple, int *return_value)
+{
+	FILE	   *fp = NULL;
+	char		output[MAXLEN];
+	int			retval = 0;
+	bool		success;
+
+	log_verbose(LOG_DEBUG, "executing:\n  %s", command);
+
+	if (outputbuf == NULL)
+	{
+		retval = system(command);
+
+		if (return_value != NULL)
+			*return_value = WEXITSTATUS(retval);
+
+		return (retval == 0) ? true : false;
+	}
+
+	fp = popen(command, "r");
+
+	if (fp == NULL)
+	{
+		log_error(_("unable to execute local command:\n%s"), command);
+		return false;
+	}
+
+
+	while (fgets(output, MAXLEN, fp) != NULL)
+	{
+		appendPQExpBuffer(outputbuf, "%s", output);
+
+		if (!feof(fp) && simple == false)
+		{
+			break;
+		}
+	}
+
+	retval = pclose(fp);
+
+	/*  */
+	success = (WEXITSTATUS(retval) == 0 || WEXITSTATUS(retval) == 141) ? true : false;
+
+	log_verbose(LOG_DEBUG, "result of command was %i (%i)", WEXITSTATUS(retval), retval);
+
+	if (return_value != NULL)
+		*return_value = WEXITSTATUS(retval);
+
+	if (outputbuf->data != NULL && outputbuf->data[0] != '\0')
+		log_verbose(LOG_DEBUG, "local_command(): output returned was:\n%s", outputbuf->data);
+	else
+		log_verbose(LOG_DEBUG, "local_command(): no output returned");
+
+	return success;
+}
+
+
+/*
+ * Execute a command via ssh on the remote host.
+ *
+ * TODO: implement SSH calls using libssh2.
+ */
+bool
+remote_command(const char *host, const char *user, const char *command, const char *ssh_options, PQExpBufferData *outputbuf)
+{
+	FILE	   *fp;
+	char		ssh_command[MAXLEN] = "";
+	PQExpBufferData ssh_host;
+
+	char		output[MAXLEN] = "";
+
+	initPQExpBuffer(&ssh_host);
+
+	if (*user != '\0')
+	{
+		appendPQExpBuffer(&ssh_host, "%s@", user);
+	}
+
+	appendPQExpBuffer(&ssh_host, "%s", host);
+
+	maxlen_snprintf(ssh_command,
+					"ssh -o Batchmode=yes %s %s %s",
+					ssh_options,
+					ssh_host.data,
+					command);
+
+	termPQExpBuffer(&ssh_host);
+
+	log_debug("remote_command():\n  %s", ssh_command);
+
+	fp = popen(ssh_command, "r");
+
+	if (fp == NULL)
+	{
+		log_error(_("unable to execute remote command:\n  %s"), ssh_command);
+		return false;
+	}
+
+	if (outputbuf != NULL)
+	{
+		/* TODO: better error handling */
+		while (fgets(output, MAXLEN, fp) != NULL)
+		{
+			appendPQExpBuffer(outputbuf, "%s", output);
+		}
+	}
+	else
+	{
+		while (fgets(output, MAXLEN, fp) != NULL)
+		{
+			if (!feof(fp))
+			{
+				break;
+			}
+		}
+	}
+
+	pclose(fp);
+
+	if (outputbuf != NULL)
+	{
+		if (outputbuf->data != NULL && outputbuf->data[0] != '\0')
+			log_verbose(LOG_DEBUG, "remote_command(): output returned was:\n%s", outputbuf->data);
+		else
+			log_verbose(LOG_DEBUG, "remote_command(): no output returned");
+	}
+
+	return true;
+}