[lttng-dev] [RFC PATCH lttng-tools] Allow environment variable LTTNG_HOME to override HOME - for lttng-tools
Amit Margalit
AMITM at il.ibm.com
Thu Jun 13 05:39:19 EDT 2013
I think I've done all that you suggested, for lttng-tools only, though,
based on cfa9a5a2b4a96e0d6a9eeddd2622a6d7c173b7ac which is the latest
master as of right now.
Here is the patch:
>From 5881718a60608d640ac1124c9c1f439a2a084707 Mon Sep 17 00:00:00 2001
From: Amit Margalit <amitm at il.ibm.com>
Date: Thu, 13 Jun 2013 12:35:13 +0300
Subject: [PATCH] Using LTTNG_HOME environment variable if exists, with
fallback to HOME
---
src/bin/lttng-relayd/utils.c | 10 +---------
src/bin/lttng-sessiond/main.c | 2 +-
src/bin/lttng-sessiond/utils.c | 10 ----------
src/bin/lttng/commands/create.c | 2 +-
src/bin/lttng/conf.c | 13 +++----------
src/bin/lttng/conf.h | 1 -
src/bin/lttng/utils.c | 3 ++-
src/common/defaults.h | 2 ++
src/common/utils.c | 15 +++++++++++++++
src/common/utils.h | 1 +
src/lib/lttng-ctl/lttng-ctl.c | 5 +++--
11 files changed, 29 insertions(+), 35 deletions(-)
diff --git a/src/bin/lttng-relayd/utils.c b/src/bin/lttng-relayd/utils.c
index ad13d32..392fab6 100644
--- a/src/bin/lttng-relayd/utils.c
+++ b/src/bin/lttng-relayd/utils.c
@@ -29,14 +29,6 @@
#include "lttng-relayd.h"
#include "utils.h"
-/*
- * Returns the HOME directory path. Caller MUST NOT free(3) the return
pointer.
- */
-static char *get_default_path(void)
-{
- return getenv("HOME");
-}
-
static char *create_output_path_auto(char *path_name)
{
int ret;
@@ -44,7 +36,7 @@ static char *create_output_path_auto(char *path_name)
char *alloc_path = NULL;
char *default_path;
- default_path = get_default_path();
+ default_path = utils_get_home_dir();
if (default_path == NULL) {
ERR("Home path not found.\n \
Please specify an output path using -o,
--output PATH");
diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 4470afc..256ffba 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -4136,7 +4136,7 @@ int main(int argc, char **argv)
DBG2("Kernel consumer cmd path: %s",
kconsumer_data.cmd_unix_sock_path);
} else {
- home_path = get_home_dir();
+ home_path = utils_get_home_dir();
if (home_path == NULL) {
/* TODO: Add --socket PATH option */
ERR("Can't get HOME directory for sockets
creation.");
diff --git a/src/bin/lttng-sessiond/utils.c
b/src/bin/lttng-sessiond/utils.c
index 5ea3374..af42ad0 100644
--- a/src/bin/lttng-sessiond/utils.c
+++ b/src/bin/lttng-sessiond/utils.c
@@ -45,13 +45,3 @@ int notify_thread_pipe(int wpipe)
return ret;
}
-
-/*
- * Return pointer to home directory path using the env variable HOME.
- *
- * No home, NULL is returned.
- */
-const char *get_home_dir(void)
-{
- return ((const char *) getenv("HOME"));
-}
diff --git a/src/bin/lttng/commands/create.c
b/src/bin/lttng/commands/create.c
index 805cdb1..ddd2983 100644
--- a/src/bin/lttng/commands/create.c
+++ b/src/bin/lttng/commands/create.c
@@ -250,7 +250,7 @@ static int create_session(void)
print_str_url = url;
} else {
/* Auto output path */
- alloc_path = config_get_default_path();
+ alloc_path = utils_get_home_dir();
if (alloc_path == NULL) {
ERR("HOME path not found.\n \
Please specify an output path
using -o, --output PATH");
diff --git a/src/bin/lttng/conf.c b/src/bin/lttng/conf.c
index b6632fc..5a0da9d 100644
--- a/src/bin/lttng/conf.c
+++ b/src/bin/lttng/conf.c
@@ -25,6 +25,7 @@
#include <unistd.h>
#include <common/error.h>
+#include <common/utils.h>
#include "conf.h"
@@ -123,14 +124,6 @@ end:
}
/*
- * Returns the HOME directory path. Caller MUST NOT free(3) the return
pointer.
- */
-char *config_get_default_path(void)
-{
- return getenv("HOME");
-}
-
-/*
* Destroys directory config and file config.
*/
void config_destroy(char *path)
@@ -161,7 +154,7 @@ end:
*/
void config_destroy_default(void)
{
- char *path = config_get_default_path();
+ char *path = utils_get_home_dir();
if (path == NULL) {
return;
}
@@ -277,7 +270,7 @@ int config_init(char *session_name)
int ret;
char *path;
- path = config_get_default_path();
+ path = utils_get_home_dir();
if (path == NULL) {
ret = -1;
goto error;
diff --git a/src/bin/lttng/conf.h b/src/bin/lttng/conf.h
index 2cb04b0..3bed59c 100644
--- a/src/bin/lttng/conf.h
+++ b/src/bin/lttng/conf.h
@@ -25,7 +25,6 @@ void config_destroy_default(void);
int config_exists(const char *path);
int config_init(char *path);
int config_add_session_name(char *path, char *name);
-char *config_get_default_path(void);
/* Must free() the return pointer */
char *config_read_session_name(char *path);
diff --git a/src/bin/lttng/utils.c b/src/bin/lttng/utils.c
index 94c4527..6041655 100644
--- a/src/bin/lttng/utils.c
+++ b/src/bin/lttng/utils.c
@@ -21,6 +21,7 @@
#include <limits.h>
#include <common/error.h>
+#include <common/utils.h>
#include "conf.h"
#include "utils.h"
@@ -36,7 +37,7 @@ char *get_session_name(void)
char *path, *session_name = NULL;
/* Get path to config file */
- path = config_get_default_path();
+ path = utils_get_home_dir();
if (path == NULL) {
goto error;
}
diff --git a/src/common/defaults.h b/src/common/defaults.h
index 66bb972..c040634 100644
--- a/src/common/defaults.h
+++ b/src/common/defaults.h
@@ -77,6 +77,8 @@
#define DEFAULT_USTCONSUMERD32_ERR_SOCK_PATH DEFAULT_USTCONSUMERD32_PATH
"/error"
/* Default lttng run directory */
+#define DEFAULT_LTTNG_HOME_ENV_VAR "LTTNG_HOME"
+#define DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR "HOME"
#define DEFAULT_LTTNG_RUNDIR "/var/run/lttng"
#define DEFAULT_LTTNG_HOME_RUNDIR "%s/.lttng"
#define DEFAULT_LTTNG_SESSIOND_PIDFILE "lttng-sessiond.pid"
diff --git a/src/common/utils.c b/src/common/utils.c
index 38f78a7..436febe 100644
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -32,6 +32,7 @@
#include <common/runas.h>
#include "utils.h"
+#include "defaults.h"
/*
* Return the realpath(3) of the path even if the last directory token
does not
@@ -584,3 +585,17 @@ int utils_get_count_order_u32(uint32_t x)
return fls_u32(x - 1);
}
+
+/**
+ * Obtain the value of LTTNG_HOME environment variable, if exists.
+ * Otherwise returns the value of HOME.
+ */
+char *utils_get_home_dir(void)
+{
+ char *val = NULL;
+ val = getenv(DEFAULT_LTTNG_HOME_ENV_VAR);
+ if (val != NULL) {
+ return val;
+ }
+ return getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR);
+}
diff --git a/src/common/utils.h b/src/common/utils.h
index 083acef..9e6fb37 100644
--- a/src/common/utils.h
+++ b/src/common/utils.h
@@ -40,5 +40,6 @@ int utils_rotate_stream_file(char *path_name, char
*file_name, uint64_t size,
uint64_t count, int uid, int gid, int out_fd, uint64_t
*new_count);
int utils_parse_size_suffix(char *str, uint64_t *size);
int utils_get_count_order_u32(uint32_t x);
+char *utils_get_home_dir(void);
#endif /* _COMMON_UTILS_H */
diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c
index a7328eb..9d76f79 100644
--- a/src/lib/lttng-ctl/lttng-ctl.c
+++ b/src/lib/lttng-ctl/lttng-ctl.c
@@ -32,6 +32,7 @@
#include <common/defaults.h>
#include <common/sessiond-comm/sessiond-comm.h>
#include <common/uri.h>
+#include <common/utils.h>
#include <lttng/lttng.h>
#include "filter/filter-ast.h"
@@ -485,7 +486,7 @@ static int set_session_daemon_path(void)
* With GNU C >= 2.1, snprintf returns the required size
(excluding closing null)
*/
ret = snprintf(sessiond_sock_path,
sizeof(sessiond_sock_path),
- DEFAULT_HOME_CLIENT_UNIX_SOCK,
getenv("HOME"));
+ DEFAULT_HOME_CLIENT_UNIX_SOCK,
utils_get_home_dir());
if ((ret < 0) || (ret >= sizeof(sessiond_sock_path))) {
goto error;
}
@@ -1543,7 +1544,7 @@ static int set_health_socket_path(void)
* With GNU C < 2.1, snprintf returns -1 if the target
buffer is too small;
* With GNU C >= 2.1, snprintf returns the required size
(excluding closing null)
*/
- home = getenv("HOME");
+ home = utils_get_home_dir();
if (home == NULL) {
/* Fallback in /tmp .. */
home = "/tmp";
--
1.7.11.7
Amit Margalit
IBM XIV - Storage Reinvented
XIV-NAS Development Team
Tel. 03-689-7774
Fax. 03-689-7230
From: David Goulet <dgoulet at efficios.com>
To: Amit Margalit/Israel/IBM at IBMIL
Cc: lttng-dev at lists.lttng.org
Date: 06/12/2013 05:46 PM
Subject: Re: [lttng-dev] [RFC PATCH lttng-tools] Allow environment
variable LTTNG_HOME to override HOME - for lttng-tools
This looks good! It appears that there are multiple callsites doing the
same
thing... We might want to just put it in src/common/utils.c with something
like
utils_get_home_dir() and use it from there.
Also, adding "LTTNG_HOME" in defaults.h as a defined value for the env.
variable
name. Finally, updating the man page would be also great. :)
Once you are ready to submit the patch, it would be good to use "git
format-patch" or send me a pull request based on git HEAD master.
Big thanks for this contribution!
David
Amit Margalit:
> Hello all,
>
> Patch functionality - If LTTNG_HOME environment variable exists, it is
used
> instead of HOME.
> Reason for patch - We are trying to deploy LTTng on a system where $HOME
is on a
> filesystem mounted read-only, but cannot afford to run lttng as a
different user
> and cannot move the home directories of users to writeable locations.
> Patch baseline: 2.2.0 rc2
>
> This patch handles only lttng-tools.
>
> I can provide the same patches against git, if asked.
>
> diff -ur lttng-tools-2.2.0-rc2-orig/src/bin/lttng/conf.c
> lttng-tools-2.2.0-rc2/src/bin/lttng/conf.c
> --- lttng-tools-2.2.0-rc2-orig/src/bin/lttng/conf.c 2013-05-06
> 21:50:59.000000000 +0300
> +++ lttng-tools-2.2.0-rc2/src/bin/lttng/conf.c 2013-06-11
> 14:17:34.681673309 +0300
> @@ -127,6 +127,11 @@
> */
> char *config_get_default_path(void)
> {
> + char *val = NULL;
> + val = getenv("LTTNG_HOME");
> + if (val != NULL) {
> + return val;
> + }
> return getenv("HOME");
> }
>
> diff -ur lttng-tools-2.2.0-rc2-orig/src/bin/lttng-relayd/utils.c
> lttng-tools-2.2.0-rc2/src/bin/lttng-relayd/utils.c
> --- lttng-tools-2.2.0-rc2-orig/src/bin/lttng-relayd/utils.c 2013-05-06
> 21:50:59.000000000 +0300
> +++ lttng-tools-2.2.0-rc2/src/bin/lttng-relayd/utils.c 2013-06-11
> 14:15:52.553673444 +0300
> @@ -34,7 +34,11 @@
> */
> static char *get_default_path(void)
> {
> - return getenv("HOME");
> + char *val = NULL;
> + val = getenv("LTTNG_HOME");
> + if (val != NULL) {
> + return val;
> + }
> }
>
> static char *create_output_path_auto(char *path_name)
> diff -ur lttng-tools-2.2.0-rc2-orig/src/bin/lttng-sessiond/utils.c
> lttng-tools-2.2.0-rc2/src/bin/lttng-sessiond/utils.c
> --- lttng-tools-2.2.0-rc2-orig/src/bin/lttng-sessiond/utils.c 2013-01-07
> 22:05:16.000000000 +0200
> +++ lttng-tools-2.2.0-rc2/src/bin/lttng-sessiond/utils.c 2013-06-11
> 14:16:16.697673412 +0300
> @@ -53,5 +53,10 @@
> */
> const char *get_home_dir(void)
> {
> + const char *val = NULL;
> + val = ((const char *) getenv("LTTNG_HOME"));
> + if (val != NULL) {
> + return val;
> + }
> return ((const char *) getenv("HOME"));
> }
> diff -ur lttng-tools-2.2.0-rc2-orig/src/lib/lttng-ctl/lttng-ctl.c
> lttng-tools-2.2.0-rc2/src/lib/lttng-ctl/lttng-ctl.c
> --- lttng-tools-2.2.0-rc2-orig/src/lib/lttng-ctl/lttng-ctl.c 2013-05-07
> 22:42:07.000000000 +0300
> +++ lttng-tools-2.2.0-rc2/src/lib/lttng-ctl/lttng-ctl.c 2013-06-11
> 14:19:15.177673176 +0300
> @@ -74,6 +74,22 @@
> int lttng_opt_verbose;
>
> /*
> + * Get the value of LTTNG_HOME if present, or HOME if not.
> + * Caller must not free the returned pointer.
> + * Used
> + */
> +static const char *get_lttng_home_dir(void)
> +{
> + const char *val = NULL;
> + val = ((const char *) getenv("LTTNG_HOME"));
> + if (val != NULL) {
> + return val;
> + }
> + return ((const char *) getenv("HOME"));
> +}
> +
> +
> +/*
> * Compare two URL destination.
> *
> * Return 0 is equal else is not equal.
> @@ -485,7 +501,7 @@
> * With GNU C >= 2.1, snprintf returns the required
size
> (excluding closing null)
> */
> ret = snprintf(sessiond_sock_path,
sizeof(sessiond_sock_path),
> - DEFAULT_HOME_CLIENT_UNIX_SOCK,
getenv("HOME"));
> + DEFAULT_HOME_CLIENT_UNIX_SOCK,
> get_lttng_home_dir());
> if ((ret < 0) || (ret >= sizeof(sessiond_sock_path))) {
> goto error;
> }
> @@ -1543,7 +1559,7 @@
> * With GNU C < 2.1, snprintf returns -1 if the target
buffer
> is too small;
> * With GNU C >= 2.1, snprintf returns the required
size
> (excluding closing null)
> */
> - home = getenv("HOME");
> + home = get_lttng_home_dir();
> if (home == NULL) {
> /* Fallback in /tmp .. */
> home = "/tmp";
>
> Thanks,
>
> Amit Margalit
> IBM XIV - /Storage Reinvented/
> XIV-NAS Development Team
> Tel. 03-689-7774
> Fax. 03-689-7230
>
>
> This body part will be downloaded on demand.
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