From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Fri, 20 Oct 2023 15:57:20 +0000 (-0400)
Subject: Revert "Add support for LTTNG_UST_HOME"
X-Git-Url: http://git.liburcu.org/?p=lttng-ust.git;a=commitdiff_plain;h=8bc1125eb851b2c52d3263c2992e6806017e98e7

Revert "Add support for LTTNG_UST_HOME"

This reverts commit 90d125c709f566f3663bf84677f100134cc618e0.

After discussion with Jeremie, we want to introduce two (not one)
environment variables:

- LTTNG_UST_APP_PATH,
- LTTNG_UST_CTL_PATH.

to accomodate use-cases where a sessiond within a container is traced by
a sessiond in the parent container. In that situation, we want the
sessiond in the parent container to access the tracee through the
LTTNG_UST_CTL_PATH, without making the unix sockets for tracing control
visible to the child container.

Therefore, remove the LTTNG_UST_HOME environment variable before it is
added into an official release.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/README.md b/README.md
index d53f8bb5..286703ba 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,3 @@
-Useless change
 LTTng-UST
 =========
 
diff --git a/doc/man/lttng-ust.3.txt b/doc/man/lttng-ust.3.txt
index 76b5c37a..0924a4de 100644
--- a/doc/man/lttng-ust.3.txt
+++ b/doc/man/lttng-ust.3.txt
@@ -1479,18 +1479,15 @@ int main(int argc, char* argv[])
 
 ENVIRONMENT VARIABLES
 ---------------------
-`LTTNG_UST_HOME`::
+`LTTNG_HOME`::
     Alternative user's home directory. This variable is useful when the
     user running the instrumented application has a non-writable home
     directory.
 +
 Unix sockets used for the communication between `liblttng-ust` and the
 LTTng session and consumer daemons (part of the LTTng-tools project)
-are located in a specific directory under `$LTTNG_UST_HOME` (or `$HOME` if
-`$LTTNG_UST_HOME` is not set).
-
-NOTE: `$LTTNG_HOME` is also supported as a fallback of `$LTTNG_UST_HOME` for
-backward compatibility reason.
+are located in a specific directory under `$LTTNG_HOME` (or `$HOME` if
+`$LTTNG_HOME` is not set).
 
 `LTTNG_UST_ALLOW_BLOCKING`::
     If set, allow the application to retry event tracing when there's
diff --git a/src/common/getenv.c b/src/common/getenv.c
index 1b5717c7..55e6ad7c 100644
--- a/src/common/getenv.c
+++ b/src/common/getenv.c
@@ -49,7 +49,6 @@ static struct lttng_env lttng_env[] = {
 	{ "LTTNG_UST_ALLOW_BLOCKING", LTTNG_ENV_SECURE, NULL, },
 	{ "HOME", LTTNG_ENV_SECURE, NULL, },
 	{ "LTTNG_HOME", LTTNG_ENV_SECURE, NULL, },
-	{ "LTTNG_UST_HOME", LTTNG_ENV_SECURE, NULL, },
 };
 
 static
diff --git a/src/lib/lttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java b/src/lib/lttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java
index 2c44a0df..cb84087a 100644
--- a/src/lib/lttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java
+++ b/src/lib/lttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java
@@ -197,29 +197,15 @@ public class LttngTcpSessiondClient implements Runnable {
 
 	private static String getHomePath() {
 		/*
-		 * The environment variable LTTNG_UST_HOME overrides LTTNG_HOME
-		 * if present.
 		 * The environment variable LTTNG_HOME overrides HOME if
 		 * defined.
 		 */
-		String lttngUstHomePath = System.getenv("LTTNG_UST_HOME");
-		String lttngHomePath = System.getenv("LTTNG_HOME");
-
-		if (lttngUstHomePath != null) {
-			/*
-			 * LTTNG_UST_HOME has priority over LTTNG_HOME and user
-			 * home directory.
-			 */
-			return lttngUstHomePath;
-		}
+		String homePath = System.getenv("LTTNG_HOME");
 
-		if (lttngHomePath != null) {
-			/* LTTNG_HOME has priority over user home directory. */
-			return lttngHomePath;
+		if (homePath == null) {
+			homePath = System.getProperty("user.home");
 		}
-
-		/* Default to the user home directory. */
-		return System.getProperty("user.home");
+		return homePath;
 	}
 
 	/**
diff --git a/src/lib/lttng-ust/lttng-ust-comm.c b/src/lib/lttng-ust/lttng-ust-comm.c
index e206456f..e57caa12 100644
--- a/src/lib/lttng-ust/lttng-ust-comm.c
+++ b/src/lib/lttng-ust/lttng-ust-comm.c
@@ -370,26 +370,16 @@ static char *get_map_shm(struct sock_info *sock_info);
 /*
  * Returns the HOME directory path. Caller MUST NOT free(3) the returned
  * pointer.
- * The following env are checked in order of priority:
- *  1 - LTTNG_UST_HOME
- *  2 - LTTNG_HOME
- *  3 - HOME
  */
 static
 const char *get_lttng_home_dir(void)
 {
        const char *val;
 
-       val = (const char *) lttng_ust_getenv("LTTNG_UST_HOME");
-       if (val != NULL) {
-               return val;
-       }
-
        val = (const char *) lttng_ust_getenv("LTTNG_HOME");
        if (val != NULL) {
                return val;
        }
-
        return (const char *) lttng_ust_getenv("HOME");
 }
 
diff --git a/src/python-lttngust/lttngust/agent.py b/src/python-lttngust/lttngust/agent.py
index b9929342..66dbbd5e 100644
--- a/src/python-lttngust/lttngust/agent.py
+++ b/src/python-lttngust/lttngust/agent.py
@@ -268,10 +268,8 @@ def _get_port_from_file(path):
 
 
 def _get_user_home_path():
-    # $LTTNG_UST_HOME overrides $LTTNG_HOME if it exist.
-    # In turn, $LTTNG_HOME overrides $HOME if it exists
-    return os.getenv('LTTNG_UST_HOME', os.getenv('LTTNG_HOME',
-        os.path.expanduser('~')))
+    # $LTTNG_HOME overrides $HOME if it exists
+    return os.getenv('LTTNG_HOME', os.path.expanduser('~'))
 
 
 _initialized = False