Today our shell scripts march on if they encounter an error during
execution. One place that this actually causes a problem is with the
Java version checker. What can happen is this: if the user botches their
installation so that the JavaVersionChecker can not be found on the
classpath, when we attempt to run the Java version checker, first an
error message that the class can not be found is displayed, and then we
print a message that their version of Java is not compatible; this
happens even if they are using a Java 8 installation. The problem is
that we should have immediately aborted when the class could not be
loaded. Since we do not exit when the shell script encounters an error,
we end up conflating failue to run the version check with a failed
version check. Instead, we really should abort the moment that one of
our scripts encounters an error. To do this, we make the following
changes:
- enable set -e and set -o pipefail
- make the Java version checker responsible for printing the error
message to the console
- remove the exit status check from the scripts
- actually on Windows, we still have to check the exit status because
there is no equivalent of set -e
- when we check for daemonization, we can no longer check the exit
status from grep because a failed grep will abort the script;
instead, we move the grep execution to be the condition for the if as
this does not trip the set -e failure conditions
- we should source elasticsearch-env before doing anything, so we move
the definition of parse_jvm_options below sourcing elasticsearch-env
- we make consistent all places where we use a subshell to use
backticks
Relates #26057
This commit fixes tests for environment-aware commands. A previous
change added a check that es.path.conf is not null. The problem is that
this system property is not being set in tests so this check trips every
single time. To fix this, we move the check into a method that can be
overridden, and then override this method in relevant places in tests to
avoid having to set the property in tests. We also add a test that this
check works as expected.
By default, the remove plugin CLI command preserves configuration
files. This is so that if a user is upgrading the plugin (which is done
by first removing the old version and then installing the new version)
they do not lose their configuration file. Yet, there are circumstances
where preserving the configuration file is not desired. This commit adds
a purge option to the remove plugin CLI command.
Relates #24981
This commit renames all rest test files to use the .yml extension
instead of .yaml. This way the extension used within all of
elasticsearch for yaml is consistent.
When installing plugin permissions, we try to set the permissions on all
installed files ourselves because a umask from the user could violate
everything needed to get the permissions right. Sadly, directories were
not handled correctly at all and so we were still left with broken
installations with umasks like 0077. This commit fixes this issue, adds
a thorough unit test for the situation, and most importantly, adds a
test that sets the umask before installing the plugin.
Relates #24527
This commit fixes an issue when deleting the plugin directory while
executing the remove plugin command. Namely, we take out a file
descriptor on the plugin directory to traverse its contents to obtain
the list of files to delete. We leaked this file descriptor. On
Unix-based filesystems, this is not a problem, deleting the plugin
directory deletes the plugin directory. On Windows though, a delete is
not executed until the last file descriptor is closed. Since we leaked
this file descriptor, the plugin was not actually deleted. This led to
test failures that tried to cleanup left behind temporary directories
but these test failures were just exposing this bug. This commit fixes
this issue by ensuring that we close the file descriptor to the plugin
directory when we are finished with it.
Relates #24266
Today when removing a plugin, we attempt to move the plugin directory to
a temporary directory and then delete that directory from the
filesystem. We do this to avoid a plugin being in a half-removed
state. We previously tried an atomic move, and fell back to a non-atomic
move if that failed. Atomic moves can fail on union filesystems when the
plugin directory is not in the top layer of the
filesystem. Interestingly, the regular move can fail as well. This is
because when the JDK is executing such a move, it first tries to rename
the source directory to the target directory and if this fails with
EXDEV (as in the case of an atomic move failing), it falls back to
copying the source to the target, and then attempts to rmdir the
source. The bug here is that the JDK never deleted the contents of the
source so the rmdir will always fail (except in the case of an empty
directory).
Given all this silliness, we were inspired to find a different
strategy. The strategy is simple. We will add a marker file to the
plugin directory that indicates the plugin is in a state of
removal. This file will be the last file out the door during removal. If
this file exists during startup, we fail startup.
Relates #24252
The plugin cli currently resides inside the elasticsearch jar. This
commit moves it into a plugin-cli jar. This is change alone is a no-op;
it does not change anything about what is loaded at runtime. But it will
allow easier testing (with fixtures in the future to test ES or maven
installation), as well as eventually not loading these classes when
starting elasticsearch.
Today when users start Elasticsearch with their Java configuration
pointing to a pre-Java 8 install, they encounter a cryptic message:
Exception in thread "main" java.lang.UnsupportedClassVersionError:
org/elasticsearch/bootstrap/Elasticsearch : Unsupported major.minor
version 52.0
They often think that they have Java 8 installed but if their JAVA_HOME
or other configuration is causing them to start with a pre-Java 8
install, this error message does not help them.
We introduce a Java version checker that runs on Java 6 as part of the
startup scripts. If the Java version is pre-Java 8, we can display a
helpful error message to the user informing them of the Java version
that the runtime was started with. Otherwise, Elasticsearch starts as it
does today.
Jason Tedor
Ryan Ernst