When an application is run as an executable archive with nested jars,
the application's own classes need to be able to load classes from
within the nested jars. This means that the application's classes need
to be loaded by the same class loader as is used for the nested jars.
When an application is launched with java -jar the contents of the
jar are on the class path of the app class loader, which is the
parent of the LaunchedURLClassLoader that is used to load classes
from within the nested jars. If the root of the jar includes the
application's classes, they would be loaded by the app class loader
and, therefore, would not be able to load classes from within the
nested jars.
Previously, this problem was resolved by LaunchedURLClassLoader being
created with a copy of all of the app class laoder's URLs and by
using an unconventional delegation model that caused it to skip its
parent (the app class loader) and jump straight to its root class
loader. This ensured that the LaunchedURLClassLoader would load both
the application's own classes and those from within any nested jars.
Unfortunately, this unusual delegation model has proved to be
problematic. We have seen and worked around some problems with Java
Agents (see gh-4911 and gh-863), but there are others (see gh-4868)
that cannot be made to work with the current delegation model.
This commit reworks LaunchedURLClassLoader to use a conventional
delegate model with the app class loader as its parent. With this
change in place, the application's own classes need to be hidden
from the app class loader via some other means. This is now achieved
by packaging application classes in BOOT-INF/classes (and, for
symmetry, nested jars are now packaged in BOOT-INF/lib). Both the
JarLauncher and the PropertiesLauncher (which supports the executable
jar layout) have been updated to look for classes and nested jars in
these new locations.
Closes gh-4897
Fixes gh-4868
Commit 5a1ee6eb added support for disabling use of start-stop-daemon
via a placeholder in the default launch script. Unfortunately, that
placeholder was subsequently broken in 81a47639.
This commit reinstates the placeholder and adds tests to verify that all
of the placeholders in the launch script can be replaced and that they
have the required default values. Furthermore, it also allows the use of
start-stop-daemon to be configured via USE_START_STOP_DAEMON in an
app’s .conf file. This allows the configuration to be changed after the
app has been built.
Closes gh-4985
Previously, the default launch script would send SIGTERM once and then
wait for up to 60 seconds for the app to have stopped. If the service
was stopped immediately after being started the first SIGTERM would
occasionally be ignored (presumably because the JVM was not yet in a
state to handle it) causing the service stop request to fail.
This commit updates the launch script to resend SIGTERM to the process
if it's still running 30 seconds after the first SIGTERM was sent.
Closes gh-4941
$arguments needs to be split on spaces so it can’t just be wrapped
in quotes. This commit updates arguments to be an array that is then
expanded ("{arguments[@]}"). The use of @ and double quotes means that
it is expanded into all elements individually quoted.
See gh-4866
81a4763 introduced a regression when multiple RUN_ARGS or JAVA_OPTS were
configured. Rather than the JVM being launched with multiple arguments
all of the RUN_ARGS or JAVA_OPTS were passed as a single argument. This
caused unexpected behaviour and typically caused the application to fail
to start.
This commit updates the quoting of the arguments the are supplied when
launching the app using start-stop-daemon so that space-separated
entries in RUN_ARGS and JAVA_OPTS remain separate.
Closes gh-4866
Previously, the launch script used which to determine the availability
of start-stop-daemon. which isn’t available by default on all OSs.
For example, it’s not available by default on CentOS 5.
This commit updates the launch script to use type when determining if
start-stop-daemon is available. This improves the portability of the
script and makes the use of type consistent throughout the script.
Closes gh-4925
Previously, the launch script would wait for the pid file to exist
before continuing. This didn’t work 100% of the time as it left a
window where the file had been created but the PID had not been written
to it that could result in an incorrect report of the app failing to
start.
This commit updates the script to wait for the file to have a size
greater than zero before continuing. This ensures that the pid has
been written to the file before the pid is read from the file and used
to check that the process is running.
Closes gh-4923
Exiting with 0 when cd fails is likely to be incorrectly interpreted
as success so we should exit with a non-zero value. Ideally, the init
script status action would exit with 4 but, at the point when
the cd is performed, we don’t even know if we’re running as an init
script. Exiting with 1 seems to be a reasonable compromise as it’s
fine for the non init-script case as well as being correct for all
init script actions other than status.
See gh-4653
Allow users to easily opt-opt of using the start-stop-daemon in the
launch script. This may be required on distros that include older
versions.
Fixes gh-4732
There’s a race condition in start-stop-daemon when --make-pidfile and
--background are used together [1]. This race condition can lead to the
command returning before the PID file has been created. The missing PID
file then causes the launch script to incorrectly report that the
service failed to start.
This commit updates the launch script to wait for up to 10 seconds for
the PID file to be created when start-stop-daemon is used to launch the
app.
Closes gh-4524
[1] https://bugs.launchpad.net/ubuntu/+source/dpkg/+bug/1036899
Update the launch script so that the PID file is not longer removed at
the beginning of the stop method. Prior to this commit if a service
wasn't able to stop on the first run, it wasn't possible to use the
launch script anymore.
Fixes gh-4369
Closes gh-4371
The HUP signal was being used to stop the service and for some reason,
sometimes it was being ignored. This commit change forces the use of the
TERM signal (the default signal of kill).
Fixes gh-4378
Closes gh-4414
By default, start-stop-daemon will chdir to the root directory before
starting the process. This prevents an application.properties file that
sits alongside the jar from being found.
This commit updates the call to start-stop-daemon to use --chdir to
set the working directory to that of the jar that’s being launched.
Closes gh-4281
Update the "INIT INFO section" of `launch.script` to include
`initInfoProvides`, `initInfoShortDescription` and `initInfoDescription`
property substitutions.
The Maven plugin has been updated to populate substitutions with
`${project.artifactId}`, `${project.name}` and `${project.description}`.
Fixes gh-4245
The init script spec [1] describes a number of requirements with which
our launch.script did not comply. This commit makes the following
corrections:
- Add support for force-reload which should be implemented by all
init scripts
- Don't fail restart if the service is already stopped or not running
- Consider stop to be successful if the service is already stopped
- Exit with 1 if stop fails (indicating a generic or unspecified error)
rather than 3 (unimplemented feature)
- Report a status of 1 if app is not running but the pid file exists
- Report a status of 3 if the app is not running (no pid file)
Closes gh-4231
[1] http://refspecs.linuxbase.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/iniscrptact.html
Previously, the launch script would always use a file named
<appname>.log to capture the application's console output. This commit
adds a variable, LOG_FILENAME, for specifying the file name defaulting
to <appname>.log.
Fixes gh-4194
Update `launch.script` to use `start-stop-daemon` when possible to
manage daemon processes. When `start-stop-daemon` is not available `su`
is used.
Closes gh-4137
The recommended usage for the java executable is:
java [-options] -jar jarfile [args...]
This commit updates the default launch script to match this recommended
usage by moving -jar to be the last option, after both the
disableJarChecking system property and any JAVA_OPTS.
Closes gh-3930
Use "return" instead of "exit" where possible, especially in
function definitions.
Also fixed the exit codes to match the LSB spec for some specific
conditions (fixes gh-3521).
Fixes gh-3199, fixes gh-3535
When writing a jar, once an entry has been written it will never be
overwritten, i.e. the first write of a given entry will win. Previously,
when repackaging a jar, the existing contents were written followed by
any libraries. This caused a problem when repackaged a WAR file and
a library needed to be unpacked as the existing entry in WEB-INF/lib
would prevent the library with the UNPACK comment from being written.
This was addressed in f761916b by inverting the order so libraries
would take precedence over entries in the source jar.
It’s now become apparent that this change in the order causes a problem
for users who are obfuscating their code. The obfuscated code exists in
the source jar but is also provided to the repackager in its original
form as a library. When libraries take precedence, this means that the
code in its original form ends up in the repackaged war and the
obfuscation is lost.
This commit updates the repackager to write libraries that require
unpacking first. This allows the UNPACK comment to be written even if
there’s also a source entry for the library. Next, source entries are
written. This allows obfuscated source entries to take precedence over
any unobfuscated library equivalents. Lastly, standard libraries that
do not require unpacking are written into the repackaged archive.
Closes gh-3444
Update the embedded launch script to include a `chkconfig` comment. This
solves the "Service doesn't support chkconfig" error when executing
the chkconfig command.
Fixes gh-3115
Update the launch script used in fully executable jars to:
- Include LSB-Header comments
- Source `.conf` files either next to the jar for additional script
configuration
Fixes gh-3243
SpringApplicationLifecycle provides basic lifecycle operations on the
current Spring Boot application (that is checking if the application has
fully started and gracefully terminate the app). It can be registered as
an MBean of the platform MBean server if a specific property is set.
The Maven plugin uses that MBean to check that the application is ready
before ending the "start" phase. It uses it to trigger a proper shutdown
of the application during the "stop" phase.
If the process has to be forked, the platform MBean server is exposed on
a configurable port so that the maven plugin can connect to it.
Such change permits the maven plugin to integrate a classical integration
test scenario where the "start" goal is invoked during the
pre-integration phase and the "stop" goal during the post-integration
phase.
Closes gh-2525
Some of the features of the launch.script were not exposed for users
to be able to control at runtime. It now accepts things like
PID_FOLDER and LOG_FOLDER as environment variables, and also adopts
a clear naming convention where only the inputs are UPPER_CASE.
Update JarWriter to set the entry timestamp for nested jars. The
timestamp is set to same time as the first (non directory) entry in
the nested jar.
This change should make it easier to created layered docker images.
Fixes gh-2807
SpringApplicationLifecycle provides lifecycle operations on the current
Spring Boot application. It can be registered as an MBean of the platform
MBean server if a specific property is set. Besides, the JMX name can
also be customized via a property in case more than one Spring Boot
application is started in the same process.
The Maven plugin uses that MBean to check that the application is ready
before ending the "start" phase. It uses it to trigger a proper shutdown
of the application during the "stop" phase.
If the process has to be forked, the platform MBean server is exposed on
a configurable port so that the maven plugin can connect to it.
Such change permits the maven plugin to integrate a classical integration
test scenario where the "start" goal is invoked during the
pre-integration phase and the "stop" goal during the post-integration
phase.
Closes gh-2525
Update the Maven and Gradle plugin to generate fully executable jar
files on Unix like machines. A launcher bash script is added to the
front of the jar file which handles execution.
The default execution script will either launch the application or
handle init.d service operations (start/stop/restart) depending on if
the application is executed directly, or via a symlink to init.d.
See gh-1117
Previously repackaging of an archive was performed in three steps:
1. Write the manifest
2. Write entries from the source archive into the destination
3. Write any libraries into the destination if they’re not already there
This worked fine for jar files, but not for war files. In the war file
case the libraries are already in the source archive’s WEB-INF/lib
directory so they’re copied into the destination in step 2. This means
that step 3 largely becomes a no-op and, crucially, the UNPACK comment
is not applied to any libraries that require it.
This commit reorders steps 2 and 3 so that the libraries are copied into
the destination first (allowing the UNPACK comment to be written, if
required) and then any entries in the source are written into the
destination if they’re not already there.
Fixes gh-2588
Add a 'module' layout for the repackager which includes all 'compile'
and 'runtime' scope dependencies and does not require a main class.
Fixes gh-1941
Prior to this commit, the repackage goal silently ignored the case of
two libraries having the same name and version but a different group.
As a result, the second library was overwriting the first one in the
repackaged jar.
This commit adds support for custom Library names and updates the
Maven and Gradle plugins so that the name includes the group ID
when there would otherwise be a duplicate.
Fixes gh-1475