jvmctl is a tool for deploying and managing Java applications on EL7
servers. It wraps systemd, git, jstack and other tools to provide a
friendly command-line interface to common deployment, process management
and debugging tasks.
- Install Python 2.7 (you probably already have it)
cd jvmctl && python setup.py install
Depending on the applications you want to run you may also want to install a JDK, version control (git, svn) and build tools (Maven, Gradle).
Application configuration files look like:
REPO=svn://svn.example.org/myapp/trunk
PORT=1234
HEAP_SIZE=512m
Basic shell-style $VARIABLE substition is supported:
JAVA_OPTS=-Dmyapp.port=$PORT
For backwards compatibility reasons lines can be prefixed with "export " (this has no effect). All options are passed to the deployment script and application as environment variables.
| Option | Default | Description |
|---|---|---|
| REPO | svn or git repository url to deploy from | |
| GIT_BRANCH | master | git branch to deploy from |
| Option | Default | Description |
|---|---|---|
| USER | webapp | unix account to run the application under |
| JAVA_HOME | /usr/lib/jvm/java-1.8.0 | path of the Java runtime to use |
| JAVA_OPTS | extra options to pass to java (system properties, GC options etc) | |
| HEAP_DUMP_PATH | /var/tmp/${NODE}.hprof | file or directory to store heap dumps |
| HEAP_SIZE | 128m | amount of memory allocated to the jvm |
| OOM_EMAIL | root@localhost | address to email out of memory errors to |
| EXEC_PREFIX | prefix to append to the executed command-line (use for wrapper scripts) |
| Option | Default | Description |
|---|---|---|
| CONTAINER | jetty | Servlet container to use or none |
| JETTY_VERSION | 9.2.5.v20141112 | Version of jetty to use (will be downloaded automatically) |
| PORT | HTTP port for servlet container | |
| ROOT_URL_PREFIX | / | path to mount web application under |
| NLA_ENVIRON | devel | (deprecated) application environment profile |
| WEBAPPS_PATH | /apps/$node | Directory to search for webapps and war files |
jvmctl delegates log handling to the systemd journald. Logs are stored
in an annotated binary format in /var/log/jornal and can be viewed, tailed and
searched using journalctl:
sudo jvmctl myapp log
sudo journalctl -u jvm:myapp -f
sudo journalctl -u jvm:myapp -n 100
See man journalctl for more options. You can also configure journald to
forward logs to syslog to write to text files or a remote logserver. See
man journald.conf.
It's installed by default on most servers, starts fast and has a large standard library with good error handling and APIs for interacting with OS services. And I know it much better than Perl. ;-)
jvmctl delegates to systemd for process and log management to systemd. While it would be possible to add support for other systems (and indeed our previous generation tool did) standardising on one platform has made the code considerably simpler. In future we may consider adding Solaris support again as SMF also provides much of the required functionality.