ctdb-common: Add utility code to get various paths

This will construct correct paths when running with CTDB_TEST_MODE.

Signed-off-by: Amitay Isaacs <amitay@gmail.com>
Reviewed-by: Martin Schwenke <martin@meltin.net>

ctdb/common/path.c

@@ -0,0 +1,179 @@
+/*
+   Construct runtime paths
+
+   Copyright (C) Amitay Isaacs  2018
+
+   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 "replace.h"
+#include "system/filesys.h"
+
+#include "lib/util/debug.h"
+
+#include "common/path.h"
+
+#define CTDB_CONFIG_FILE	"ctdb.conf"
+
+struct {
+	char *basedir;
+	char etcdir[PATH_MAX];
+	char rundir[PATH_MAX];
+	char vardir[PATH_MAX];
+	bool test_mode;
+	bool basedir_set;
+	bool etcdir_set;
+	bool rundir_set;
+	bool vardir_set;
+} ctdb_paths = {
+	.etcdir = CTDB_ETCDIR,
+	.rundir = CTDB_RUNDIR,
+	.vardir = CTDB_VARDIR,
+};
+
+static void path_set_basedir(void)
+{
+	const char *t;
+
+	t = getenv("CTDB_TEST_MODE");
+	if (t == NULL) {
+		goto done;
+	}
+
+	ctdb_paths.test_mode = true;
+
+	ctdb_paths.basedir = getenv("CTDB_BASE");
+	if (ctdb_paths.basedir == NULL) {
+		D_ERR("Broken CTDB setup, CTDB_BASE not set in test mode\n");
+		abort();
+	}
+
+done:
+	ctdb_paths.basedir_set = true;
+}
+
+static bool path_construct(char *path, const char *subdir)
+{
+	char p[PATH_MAX];
+	int len;
+
+	if (! ctdb_paths.basedir_set) {
+		path_set_basedir();
+	}
+
+	if (! ctdb_paths.test_mode) {
+		return true;
+	}
+
+	if (subdir == NULL) {
+		len = snprintf(p, sizeof(p), "%s", ctdb_paths.basedir);
+	} else {
+		len = snprintf(p,
+			       sizeof(p),
+			       "%s/%s",
+			       ctdb_paths.basedir,
+			       subdir);
+	}
+
+	if (len >= sizeof(p)) {
+		return false;
+	}
+
+	strncpy(path, p, PATH_MAX);
+	return true;
+}
+
+const char *path_etcdir(void)
+{
+	bool ok;
+
+	if (! ctdb_paths.etcdir_set) {
+		ok = path_construct(ctdb_paths.etcdir, NULL);
+		if (!ok) {
+			D_ERR("Failed to construct ETCDIR\n");
+		} else {
+			ctdb_paths.etcdir_set = true;
+		}
+	}
+
+	return ctdb_paths.etcdir;
+}
+
+const char *path_rundir(void)
+{
+	bool ok;
+
+	if (! ctdb_paths.rundir_set) {
+		ok = path_construct(ctdb_paths.rundir, "run");
+		if (!ok) {
+			D_ERR("Failed to construct RUNDIR\n");
+		} else {
+			ctdb_paths.rundir_set = true;
+		}
+	}
+
+	return ctdb_paths.rundir;
+}
+
+const char *path_vardir(void)
+{
+	bool ok;
+
+	if (! ctdb_paths.rundir_set) {
+		ok = path_construct(ctdb_paths.vardir, "var");
+		if (!ok) {
+			D_ERR("Failed to construct VARDIR\n");
+		} else {
+			ctdb_paths.vardir_set = true;
+		}
+	}
+
+	return ctdb_paths.vardir;
+}
+
+char *path_etcdir_append(TALLOC_CTX *mem_ctx, const char *path)
+{
+	return talloc_asprintf(mem_ctx, "%s/%s", path_etcdir(), path);
+}
+
+char *path_rundir_append(TALLOC_CTX *mem_ctx, const char *path)
+{
+	return talloc_asprintf(mem_ctx, "%s/%s", path_rundir(), path);
+}
+
+char *path_vardir_append(TALLOC_CTX *mem_ctx, const char *path)
+{
+	return talloc_asprintf(mem_ctx, "%s/%s", path_vardir(), path);
+}
+
+char *path_config(TALLOC_CTX *mem_ctx)
+{
+	return path_etcdir_append(mem_ctx, CTDB_CONFIG_FILE);
+}
+
+char *path_socket(TALLOC_CTX *mem_ctx, const char *daemon)
+{
+	return talloc_asprintf(mem_ctx,
+			       "%s/%s.socket",
+			       path_rundir(),
+			       daemon);
+}
+
+char *path_pidfile(TALLOC_CTX *mem_ctx, const char *daemon)
+{
+	return talloc_asprintf(mem_ctx,
+			       "%s/%s.pid",
+			       path_rundir(),
+			       daemon);
+}

ctdb/common/path.h

@@ -0,0 +1,37 @@
+/*
+   Construct runtime paths
+
+   Copyright (C) Amitay Isaacs  2018
+
+   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/>.
+*/
+
+#ifndef __CTDB_PATH_H__
+#define __CTDB_PATH_H__
+
+#include <talloc.h>
+
+const char *path_etcdir(void);
+const char *path_rundir(void);
+const char *path_vardir(void);
+
+char *path_etcdir_append(TALLOC_CTX *mem_ctx, const char *path);
+char *path_rundir_append(TALLOC_CTX *mem_ctx, const char *path);
+char *path_vardir_append(TALLOC_CTX *mem_ctx, const char *path);
+
+char *path_config(TALLOC_CTX *mem_ctx);
+char *path_socket(TALLOC_CTX *mem_ctx, const char *daemon);
+char *path_pidfile(TALLOC_CTX *mem_ctx, const char *daemon);
+
+#endif /* __CTDB_PATH_H__ */

ctdb/wscript

@@ -400,7 +400,7 @@ def build(bld):
                                              pidfile.c run_proc.c
                                              hash_count.c run_event.c
                                              sock_client.c version.c
-                                             cmdline.c
+                                             cmdline.c path.c
                                           '''),
                         deps='''samba-util sys_rw tevent-util
                                 replace talloc tevent tdb popt''')