Deprecated. Use remote_syslog2 instead of this repo
remote_syslog Ruby daemon & sender
remote_syslog has been rewritten in Go as remote_syslog2. As a standalone binary, remote_syslog2 has fewer dependencies. It also depends on less code between the daemon and the OS.
Use remote_syslog2 instead of this repo.
Introduction
Lightweight Ruby daemon to tail one or more log files and transmit UDP syslog messages to a remote syslog host (centralized log aggregation).
remote_syslog generates UDP packets itself instead of depending on a system syslog daemon, so its configuration doesn't affect system-wide logging - syslog is just the transport.
Uses:
- collecting logs from servers & daemons which don't natively support syslog
- when reconfiguring the system logger is less convenient than a purpose-built daemon (e.g., automated app deployments)
- aggregating files not generated by daemons (e.g., package manager logs)
The library can also be used to generate one-off log messages from Ruby code.
Tested with the hosted log management service Papertrail and should work for transmitting to any syslog server.
Installation
Install the gem, which includes a binary called "remote_syslog":
$ [sudo] gem install remote_syslog
Optionally, create a log_files.yml with the log file paths to read and the host/port to log to (see examples/log_files.yml.example). These can also be specified as command-line arguments (below).
Usage
Usage: remote_syslog [OPTION]... <FILE>...
Options:
-c, --configfile PATH Path to config (/etc/log_files.yml)
-d, --dest-host HOSTNAME Destination syslog hostname or IP (logs.papertrailapp.com)
-p, --dest-port PORT Destination syslog port (514)
-D, --no-detach Don't daemonize and detach from the terminal
-f, --facility FACILITY Facility (user)
--hostname HOST Local hostname to send from
-P, --pid-dir DIRECTORY DEPRECATED: Directory to write .pid file in
--pid-file FILENAME Location of the PID file (default /var/run/remote_syslog.pid)
--parse-syslog Parse file as syslog-formatted file
-s, --severity SEVERITY Severity (notice)
--strip-color Strip color codes
--tls Connect via TCP with TLS
--tcp Connect via TCP (no TLS)
--new-file-check-interval INTERVAL
Time between checks for new files
Advanced options:
--[no-]eventmachine-tail Enable or disable using eventmachine-tail
--debug-log FILE Log internal debug messages
--debug-level LEVEL Log internal debug messages at level
Common options:
-h, --help Show this message
--version Show version
Example:
$ remote_syslog -c configs/logs.yml -p 12345 /var/log/mysqld.log
Example
Typical:
$ remote_syslog
Daemonize and collect messages from files listed in ./config/logs.yml as
well as the file /var/log/mysqld.log. Send to port logs.papertrailapp.com:12345:
$ remote_syslog -c configs/logs.yml -p 12345 /var/log/mysqld.log
Stay attached to the terminal, look for and use /etc/log_files.yml if it
exists, write PID to /tmp/remote_syslog.pid, and send with facility local0
to a.example.com:514:
$ remote_syslog -D -d a.example.com -f local0 --pid-file /tmp/remote_syslog.pid /var/log/mysqld.log
Windows
Windows is not currently supported, though in certain situations it may work.
Auto-starting at boot
The gem includes sample init files, also available here. You may be able to:
$ cp examples/remote_syslog.init.d /etc/init.d/remote_syslog
$ chmod 755 /etc/init.d/remote_syslog
And then ensure it's started at boot, either by using:
$ sudo update-rc.d remote_syslog defaults
or by creating a link manually:
$ sudo ln -s /etc/init.d/remote_syslog /etc/rc3.d/S30remote_syslog
remote_syslog will daemonize by default.
Init files: remote_syslog.init.d (init.d), OS X launchd, supervisor, Ubuntu upstart
Optional: rvm
Remember that when using a Ruby version manager such as rvm,
your interactive shell and init files need the version manager environment loaded.
The rvm init.d instructions show how to
create a wrapper script for the init files to run. A typical example is:
rvm wrapper ruby-1.9.3-p392 bootup remote_syslog
.. where ruby-1.9.3-p392 is the desired Ruby from rvm list. rvm will output
the path to the new wrapper script which it created. Edit the init file to run the
new wrapper script instead of running remote_syslog directly.
Sending messages securely
If the receiving system supports sending syslog over TCP with TLS, you can
pass the --tls option when running remote_syslog:
$ remote_syslog --tls -p 1234 /var/log/mysqld.log
Important: remote_syslog depends on I/O code provided by the Ruby
VM, eventmachine library, and OS. There is at least one environment
and failure case where remote_syslog will not reconnect when using the
--tls option. Although we've never been able to reproduce this problem,
enough Papertrail customers have run into it that we'd suggest looking at
alternative solutions. One of those is forwarding data to rsyslog and
then using its TLS capabilities to log to Papertrail. For more
information on that and other alternatives, please contact
[email protected]
Configuration
By default, the gem looks for a configuration in /etc/log_files.yml.
The gem comes with a sample config. Optionally:
$ cp examples/log_files.yml.example /etc/log_files.yml
log_files.yml has filenames to log from (as an array) and hostname and port to log to (as a hash). Wildcards are supported using * and standard shell globbing. Filenames given on the command line are additive to those in the config file.
Only 1 destination server is supported; the command-line argument wins.
files:
- /var/log/httpd/access_log
- /var/log/httpd/error_log
- /var/log/mysqld.log
- /var/run/mysqld/mysqld-slow.log
destination:
host: logs.papertrailapp.com
port: 12345
remote_syslog sends the name of the file without a path ("mysqld.log") as the syslog tag (program name). RFCs 3164 and 5424 limit the tag to 32 characters. Longer filenames are truncated to 32 characters.
After changing the configuration file, restart remote_syslog using the
init script or by manually killing and restarting the process. For example:
/etc/init.d/remote_syslog restart
Advanced Configuration (Optional)
Here's an advanced config which uses all options.
Override hostname
Provide --hostname somehostname or use the hostname configuration option:
hostname: somehostname
Verify server certificate
Provide the public key for the remote host when using TLS:
ssl_server_cert: syslog.crt
Use a client certificate
Provide a client certificate when connecting via TLS:
ssl_client_cert_chain: syslog_client.crt
ssl_client_private_key: syslog_client.key
Detecting new files
remote_syslog automatically detects and activates new log files that match
its file specifiers. For example, *.log may be provided as a file specifier,
and remote_syslog will detect a some.log file created after it was started.
Globs are re-checked every 10 seconds. Ruby's Dir.glob is used.
Note: messages may be written to files in the 0-10 seconds between when the file is created and when the periodic glob check detects it. This data is not currently acted on, though the default behavior may change in the future.
Also, explicitly-provided filenames need not exist when remote_syslog is
started. remote_syslog can be pre-configured to monitor log files which are
created later (or may never be created).
If globs are specified on the command-line, enclose each one in single-quotes
('*.log') so the shell passes the raw glob string to remote_syslog (rather
than the current set of matches). This is not necessary for globs defined in
the config file.
Log rotation
External log rotation scripts often move or remove an existing log file
and replace it with a new one (at a new inode). The Linux standard script
logrotate supports a copytruncate config
option. With that option, logrotate will copy files, operate on the copies,
and truncate the original so that the inode remains the same.
This comes closest to ensuring that programs watching these files (including
remote_syslog) will not be affected by, or need to be notified of, the
rotation. The only tradeoff of copytruncate is slightly higher disk usage
during rotation, so we recommend this option whether or not you use
remote_syslog.
Excluding files from being sent
Provide one or more regular expressions to prevent certain files from being matched.
exclude_files:
- \.\d$
- .bz2
- .gz
Multiple instances
Run multiple instances to support more than one message-specific file format or to specify unique syslog hostnames.
To do that, provide an alternate PID path as a command-line option to the additional instance(s). For example:
--pid-file /var/run/remote_syslog_2.pid
Parse fields from log messages
Rarely needed. Usually only used when remote_syslog is watching files
generated by syslogd (rather than by apps), like /var/log/messages.
remote_syslog can parse the program and hostname from the log line. When one file contains logs from multiple programs (like with syslog), the log line may include text that is not part of the log message, like a timestamp, hostname, or program name. remote_syslog will extract those and use them in the corresponding syslog packet fields.
To do that, use the config file option parse_fields with the name of a
format supported by remote_syslog, or your own regex. Included format names
are syslog and rfc3339. For example:
parse_fields: syslog
The included syslog format uses the regex (\w+ \d+ \S+) (\S+) ([^:]+): (.*)
to parse standard syslog lines like this:
Jul 18 08:25:08 hostname programname[1234]: The log message
The included rfc3339 format uses the regex (\S+) (\S+) ([^: ]+):? (.*) to
parse syslog lines with high-precision RFC 3339 timestamps, like this:
2011-07-16T08:25:08.651413-07:00 hostname programname[1234]: The log message
To parse a format other than those, provide your own regex. It should include 4 backreferences to parse, in order: timestamp, system name, program name, message.
Match and return empty strings for any empty positions where the log line doesn't provide a value. For example, given the log message:
something-meaningless The log message
One could use a regex to ignore "something-meaningless" (and not to extract a program or hostname). To ignore that prefix and return 3 empty values then the log message, use parse_fields with this regex:
parse_fields: "something-meaningless ()()()(.*)"
Per-file regexes are not supported. Run multiple instances with different config files.
Excluding lines matching a pattern
There may be certain log messages that you do not want to be sent. These may repetitive log lines that are "noise" that you might not be able to filter out easily from the respective application. To filter these lines, use the exclude_patterns with an array or regexes:
exclude_patterns:
- exclude this
- \d+ things
Prepending a string to log messages
Use prepend to prepend a string to every log message before
transmitting. The string is prepended to the log message body, as if it
occurred at the start of every log file line. Include a trailing space
if desired.
Examples:
prepend: important:
or:
prepend: cafebabe-1024-4096-badd-1234abcd1234
Choosing app name
remote_syslog uses the log file name (like "access_log") as the syslog program name, or what the syslog RFCs call the "tag." This is ideal unless remote_syslog watches many files that have the same name.
In that case, tell remote_syslog to set another program name by creating symbolic link to the generically-named file:
cd /path/to/logs
ln -s generic_name.log unique_name.log
Point remote_syslog at unique_name.log. It will use that as the program name.
Troubleshooting
Installation
gem not found
Install a Ruby distribution, which typically takes a minute.
g++ not found
Install gcc and g++ so this system can compile C/C++ source. Installation
is typically sudo yum install gcc-c++ (RPM-based distros) or sudo apt-get
install build-essential (.deb-based distros).
Getting Encryption not available... or TLS is not supported...
The exact error might appear as:
Encryption not available on this event-machine
or
TLS is not supported by eventmachine installed on this system. The openssl-devel/openssl-dev package must be installed before installing eventmachine.
Install the OpenSSL C++ package for your distribution, then reinstall the eventmachine. For example:
- .deb distros like Ubuntu:
sudo apt-get install libssl-dev - RPM distros like Fedora
sudo yum install openssl-devel
Then:
gem install eventmachine -f
Getting no such file to load -- mkmf (LoadError)?
Try these:
- Ubuntu: determine which Ruby version is active with
ruby -v.
For 1.8.7: sudo apt-get install build-essential ruby1.8 ruby1.8-dev rubygems.
For 1.9.x, including 1.9.1 and 1.9.3: sudo apt-get install build-essential ruby1.9.1-dev.
For 2.0: sudo apt-get install build-essential ruby2.0-dev
Fedora:
sudo yum install ruby-devel.- Getting errors about missing header files, like
ssl.cpp? Try:
- Getting errors about missing header files, like
CentOS:
sudo yum install libstdc++-devel ruby-devel
Getting Package ruby1.8 is not available...
The exact error might appear as:
Package ruby1.8 is not available, but is referred to by another package.` and/or `Package rubygems is not available, but is referred to by another package.` on Ubuntu 14.04
Ubuntu 14.04 changed the name of the ruby 1.8.7 packages. Try this instead:
sudo apt-get install build-essential ruby-full ruby
Freezes at the compilation stage
This can happen when the system is low on memory. The installation process starts up
the compiler, but it gets killed as soon it consumes too much memory.
Tailing /var/log/syslog or /var/log/messages will confirm whether or not this is
occurring.
The solution is to temporarily stop any memory intensive tasks, install remote_syslog, and then restart them.
Operations
Reconnect failures
remote_syslog depends on I/O code provided by the Ruby VM, eventmachine library,
and OS. There is at least one environment and failure case where remote_syslog will
not reconnect when using the --tls option. Although we've never been able to
reproduce this problem (and known occurrences are correspondingly rare), the dependency
and problem are worth noting.
remote_syslog not found?
It may not be in your path. Run find / -name remote_syslog to locate it, then run it
with the full path (such as /var/lib/gems/1.8/bin/remote_syslog).
The system rebooted and remote_syslog didn't start
Install an init file.
Logs not appearing?
Two commands are particularly useful for observing remote_syslog
behavior. First, its own debugging:
remote_syslog --debug-level DEBUG --debug-log remote_syslog.log
This will write internal operations to the file remote_syslog.log.
Second, strace or ktrace shows the interaction between remote_syslog
and the OS. To run strace against an existing remote_syslog instance
(process ID 12345):
strace -fp 12345 -s 500
Feel free to ask questions or report bugs.
Reporting bugs
- See whether the issue has already been reported: https://github.com/papertrail/remote_syslog/issues/
- If you don't find one, create an issue with a repro case.
Contributing
Once you've made your great commits: