[2/2] mesos git commit: Avoided modifying process environment.

[ti...@apache.org]

Avoided modifying process environment.

This code modified the process environment in order to support upgrading
on the fly from old-style libprocess SSL variables \`SSL\_\` to
\`LIBPROCESS_SSL\_\`. Modifying the process environment at this point is
not safe as other actors might concurrently read out that same
environment.

Instead avoid changing the process environment altogether since flags
can just as well be read from a map.

Review: https://reviews.apache.org/r/52154/


Project: http://git-wip-us.apache.org/repos/asf/mesos/repo
Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/acbebcc6
Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/acbebcc6
Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/acbebcc6

Branch: refs/heads/master
Commit: acbebcc6f13d75956022f849ef93955fdfb33f4c
Parents: 677faaf
Author: Benjamin Bannier <be...@mesosphere.io>
Authored: Fri Oct 7 14:56:59 2016 +0200
Committer: Till Toenshoff <to...@me.com>
Committed: Fri Oct 7 14:56:59 2016 +0200

----------------------------------------------------------------------
 3rdparty/libprocess/src/openssl.cpp | 40 +++++++++++++++++---------------
 1 file changed, 21 insertions(+), 19 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/mesos/blob/acbebcc6/3rdparty/libprocess/src/openssl.cpp
----------------------------------------------------------------------
diff --git a/3rdparty/libprocess/src/openssl.cpp b/3rdparty/libprocess/src/openssl.cpp
index d73abbd..5ddb10d 100644
--- a/3rdparty/libprocess/src/openssl.cpp
+++ b/3rdparty/libprocess/src/openssl.cpp
@@ -297,24 +297,24 @@ void reinitialize()
   // environment. See comment at top of openssl.hpp for a full list.
   //
   // NOTE: We used to look for environment variables prefixed by SSL_.
-  // To be backward compatible, for each environment variable prefixed
-  // by SSL_, we generate the corresponding LIBPROCESS_SSL_ version.
-  // See details in MESOS-5863.
-  map<string, string> environments = os::environment();
-  foreachpair (const string& key, const string& value, environments) {
-    if (strings::startsWith(key, "SSL_")) {
-      const string new_key = "LIBPROCESS_" + key;
-      if (environments.count(new_key) == 0) {
-        os::setenv(new_key, value);
-      } else if (environments[new_key] != value) {
-        LOG(WARNING) << "Mismatched SSL environment variables: "
-                     << key << "=" << value << ", "
-                     << new_key << "=" << environments[new_key];
-      }
+  // To be backward compatible, we interpret environment variables
+  // prefixed with either SSL_ and LIBPROCESS_SSL_ where the latter
+  // one takes precedence. See details in MESOS-5863.
+  map<string, Option<string>> environment_ssl =
+      ssl_flags->extract("SSL_");
+  map<string, Option<string>> environments =
+      ssl_flags->extract("LIBPROCESS_SSL_");
+  foreachpair (
+      const string& key, const Option<string>& value, environment_ssl) {
+    if (environments.count(key) > 0 && environments.at(key) != value) {
+      LOG(WARNING) << "Mismatched values for SSL environment variables "
+                   << "SSL_" << key << " and "
+                   << "LIBPROCESS_SSL_" << key;
     }
   }
+  environments.insert(environment_ssl.begin(), environment_ssl.begin());
 
-  Try<flags::Warnings> load = ssl_flags->load("LIBPROCESS_SSL_");
+  Try<flags::Warnings> load = ssl_flags->load(environments);
   if (load.isError()) {
     EXIT(EXIT_FAILURE)
       << "Failed to load flags from environment variables "
@@ -489,16 +489,18 @@ void reinitialize()
       // defaults.
       string ca_dir;
 
-      if (environments.count(X509_get_default_cert_dir_env()) > 0) {
-        ca_dir = environments.at(X509_get_default_cert_dir_env());
+      const map<string, string> environment = os::environment();
+
+      if (environment.count(X509_get_default_cert_dir_env()) > 0) {
+        ca_dir = environment.at(X509_get_default_cert_dir_env());
       } else {
         ca_dir = X509_get_default_cert_dir();
       }
 
       string ca_file;
 
-      if (environments.count(X509_get_default_cert_file_env()) > 0) {
-        ca_file = environments.at(X509_get_default_cert_file_env());
+      if (environment.count(X509_get_default_cert_file_env()) > 0) {
+        ca_file = environment.at(X509_get_default_cert_file_env());
       } else {
         ca_file = X509_get_default_cert_file();
       }