I am trying to adjust path name so that it no longer has the time stamp attached to the end. I am input many different logs so it would be impractical to write a conditional filter for every possible log. If possible I would just like to trim the last nine characters of the value.
For example "random.log-20140827" would become "random.log".
mutate {
gsub => [
"path", "-\d{8}$", ""
]
}
So if you know it's always going to be random.log-something --
if [path] =~ /random.log/ {
mutate {
replace => ["path", "random.log"]
}
}
If you want to "fix" anything that has a date in it:
if [path] =~ /-\d\d\d\d\d\d\d\d/ {
grok {
match => [ "path", "^(?<pathPrefix>[^-]+)-" ]
}
mutate {
replace => ["path", "%{pathPrefix}"]
remove_field => "pathPrefix"
}
}
Of the two, the first is going to be less compute intensive.
I haven't tested either of these, but they should work.
Related
I wonder if there is a way of using a substring when using add_field in mutate filter, maybe with %{field} syntax.
For example:
filter {
mutate {
add_field => { "shorter_field" => "%{field[0:4]}" }
}
}
I saw solutions using ruby filters, but I prefer only using mutate because I have a sequence of operation I'm doing using the filter and I prefer keeping it simple
Try this:
(assuming that you need first 4 characters of the field.)
CODE:
filter {
mutate {
gsub => ["shorter_field", "(?<=^....)(.*)", ""]
}
}
In here all characters except first 4 characters will be removed from shorter_field.
example:
INPUT:
shorter_field = example_value
OUTPUT:
shorter_field = exam
How can I trim to only the last part of a key in logstash?
I have URLs formatted in the form of http://aaa.bbb/get?a=1&b=2, putting them into 'request' and splitting the field based on '?&' to save the GET parameters.
I care only about the specific API call, and not the host or protocol. What filter(s) can I chain to keep only the part after the final '/'? I've read up a bit on patterns but haven't stumbled upon how to reference the last part of a split field.
grok {
match => [ "message", "%{TIMESTAMP_ISO8601:timestamp}
%{NOTSPACE:loadbalancer} %{IP:client_ip}:%{NUMBER:client_port:int}
%{IP:backend_ip}:%{NUMBER:backend_port:int}
%{NUMBER:request_processing_time:float}
%{NUMBER:backend_processing_time:float}
%{NUMBER:response_processing_time:float}
%{NUMBER:elb_status_code:int}
%{NUMBER:backend_status_code:int}
%{NUMBER:received_bytes:int} %{NUMBER:sent_bytes:int}
%{QS:request}" ]
}
date {
match => [ "timestamp", "ISO8601" ]
}
kv {
field_split => "&?"
source => "request"
}
I would suggest taking the existing URI-related patterns and modifying them to your needs. You will note that URIPATHPARAM parses out the URIPATH and URIPARAM but doesn't shove them into fields.
So, make your own URIPATHPARAM:
MYURIPATHPARM URIPATHPARAM %{URIPATH:uripath}(?:%{URIPARAM:uriparam})?
and then call it from your own URI:
MYURI URI %{URIPROTO}://(?:%{USER}(?::[^#]*)?#)?(?:%{URIHOST})?(?:%{MYURIPATHPARAM})?
In your previous grok{}, you ended up with %{request}. Make a new grok{} that runs [request] through MYURI, and you should end up with the two fields that you're after.
I have log files coming in to an ELK stack. I want to copy a field (foo) in order to perform various mutations on it, However the field (foo) isn't always present.
If foo doesn't exist, then bar still gets created, but is assigned the literal string "%{foo}"
How can I perform a mutation only if a field exists?
I'm trying to do something like this.
if ["foo"] {
mutate {
add_field => "bar" => "%{foo}
}
}
To check if field foo exists:
1) For numeric type fields use:
if ([foo]) {
...
}
2) For types other than numeric like boolean, string use:
if ("" in [foo]) {
...
}
"foo" is a literal string.
[foo] is a field.
# technically anything that returns 'true', so good for numbers and basic strings:
if [foo] {
}
# contains a value
if [foo] =~ /.+/ {
}
On Logstash 2.2.2, the ("" in [field]) construct does not appear to work for me.
if ![field] { }
does, for a non-numerical field.
It's 2020 and none of the above answers are quite correct. I've been working with logstash since 2014 and expressions in filter were, are and will be a thing...
For example, you may have a boolean field with false value and with the above solutions you may not know if false is the value of the field or the resulting value of the expression because the field doesn't exists.
Workaround for checking if a field exists in all versions
I think all versions of logstash supports [#metadata] field. That is, a field that will not be visible for output plugins and lives only in the filtering state. So this is what I have to workaround:
filter {
mutate {
# we use a "temporal" field with a predefined arbitrary known value that
# lives only in filtering stage.
add_field => { "[#metadata][testField_check]" => "unknown arbitrary value" }
# we copy the field of interest into that temporal field.
# If the field doesn't exist, copy is not executed.
copy => { "testField" => "[#metadata][testField_check]" }
}
# now we now if testField didn't exists, our field will have
# the initial arbitrary value
if [#metadata][testField_check] == "unknown arbitrary value" {
# just for debugging purpouses...
mutate { add_field => { "FIELD_DID_NOT_EXISTED" => true }}
} else {
# just for debugging purpouses...
mutate { add_field => { "FIELD_DID_ALREADY_EXISTED" => true }}
}
}
Old solution for logstash prior version 7.0.0
Check my issue in github.
I've been struggling a lot with expressions in logstash. My old solution worked until version 7. This was for boolean fields, for instance:
filter {
# if the field does not exists, `convert` will create it with "false" string. If
# the field exists, it will be the boolean value converted into string.
mutate { convert => { "field" => "string" } }
# This condition breaks on logstash > 7 (see my bug report). Before version 7,
# this condition will be true if a boolean field didn't exists.
if ![field] {
mutate { add_field => { "field" => false } }
}
# at this stage, we are sure field exists, so make it boolean again
mutate { convert => { "field" => "boolean" } }
}
I'm creating a logstash grok filter to pull events out of a backup server, and I want to be able to test a field for a pattern, and if it matches the pattern, further process that field and pull out additional information.
To that end I'm embedding an if statement within the grok statement itself. This is causing the test to fail with Error: Expected one of #, => right after the if.
This is the filter statement:
filter {
grok {
patterns_dir => "./patterns"
# NetWorker logfiles have some unusual fields that include undocumented engineering codes and what not
# time is in 12h format (ugh) so custom patterns need to be used.
match => [ "message", "%{NUMBER:engcode1} %{DATESTAMP_12H:timestamp} %{NUMBER:engcode2} %{NUMBER:engcode3} %{NUMBER:engcode4} %{NUMBER:ppid} %{NUMBER:pid} %{NUMBER:engcode5} %{WORD:processhost} %{WORD:processname} %{GREEDYDATA:daemon_message}" ]
# attempt to find completed savesets and pull that info from the daemon_message field
if [daemon_message] =~ /done\ saving\ to\ pool/ {
grok {
match => [ "daemon_message", "%{WORD:savehost}\:%{WORD:saveset} done saving to pool \'%{WORD:pool}\' \(%{WORD:volume}\) %{WORD:saveset_size}" ]
}
}
}
date {
# This is requred to set the time from the logline to the timestamp and not have it create it's own.
# Note the use of the trailing 'a' to denote AM or PM.
match => ["timestamp", "MM/dd/yyyy HH:mm:ss a"]
}
}
This block fails with the following:
$ /opt/logstash/bin/logstash -f ./networker_daemonlog.conf --configtest
Error: Expected one of #, => at line 12, column 12 (byte 929) after # Basic dumb simple networker daemon log grok filter for the NetWorker daemon.log
# no smarts to this and not really pulling any useful info from the files (yet)
filter {
grok {
... lines deleted ...
# attempt to find completed savesets and pull that info from the daemon_message field
if
I'm new to logstash, and I realise that using a conditional within the grok statement may not be possible, but I'd prefer doing conditional processing this way to additional match lines as this would leave the daemon_message field intact for other uses while pulling out the data I want.
ETA: I should also point out that totally removing the if statement allows the configtest to pass and the filter to parse logs.
Thanks in advance...
Conditionals go outside the filters, so something like:
if [field] == "value" {
grok {
...
}
]
would be correct. In your case, do the first grok, then test to run the second, i.e.:
grok {
match => [ "message", "%{NUMBER:engcode1} %{DATESTAMP_12H:timestamp} %{NUMBER:engcode2} %{NUMBER:engcode3} %{NUMBER:engcode4} %{NUMBER:ppid} %{NUMBER:pid} %{NUMBER:engcode5} %{WORD:processhost} %{WORD:processname} %{GREEDYDATA:daemon_message}" ]
}
if [daemon_message] =~ /done\ saving\ to\ pool/ {
grok {
match => [ "daemon_message", "%{WORD:savehost}\:%{WORD:saveset} done saving to pool \'%{WORD:pool}\' \(%{WORD:volume}\) %{WORD:saveset_size}" ]
}
}
This is really running two regexps for a record that matches. Since grok will only make fields when the regexp matches, you can do this:
grok {
match => [ "message", "%{NUMBER:engcode1} %{DATESTAMP_12H:timestamp} %{NUMBER:engcode2} %{NUMBER:engcode3} %{NUMBER:engcode4} %{NUMBER:ppid} %{NUMBER:pid} %{NUMBER:engcode5} %{WORD:processhost} %{WORD:processname} %{GREEDYDATA:daemon_message}" ]
}
grok {
match => [ "daemon_message", "%{WORD:savehost}\:%{WORD:saveset} done saving to pool \'%{WORD:pool}\' \(%{WORD:volume}\) %{WORD:saveset_size}" ]
}
You'd have to measure the performance across your actual log files since this will run fewer regexps, but the second one is more complicated.
If you really want to go nuts, you can do all of this in one grok{}, using the break_on_match feature.
I've got log lines in the following format and want to extract fields:
[field1: content1] [field2: content2] [field3: content3] ...
I neither know the field names, nor the number of fields.
I tried it with backreferences and the sprintf format but got no results:
match => [ "message", "(?:\[(\w+): %{DATA:\k<-1>}\])+" ] # not working
match => [ "message", "(?:\[%{WORD:fieldname}: %{DATA:%{fieldname}}\])+" ] # not working
This seems to work for only one field but not more:
match => [ "message", "(?:\[%{WORD:field}: %{DATA:content}\] ?)+" ]
add_field => { "%{field}" => "%{content}" }
The kv filter is also not appropriate because the content of the fields may contain whitespaces.
Is there any plugin / strategy to fix this problem?
Logstash Ruby Plugin can help you. :)
Here is the configuration:
input {
stdin {}
}
filter {
ruby {
code => "
fieldArray = event['message'].split('] [')
for field in fieldArray
field = field.delete '['
field = field.delete ']'
result = field.split(': ')
event[result[0]] = result[1]
end
"
}
}
output {
stdout {
codec => rubydebug
}
}
With your logs:
[field1: content1] [field2: content2] [field3: content3]
This is the output:
{
"message" => "[field1: content1] [field2: content2] [field3: content3]",
"#version" => "1",
"#timestamp" => "2014-07-07T08:49:28.543Z",
"host" => "abc",
"field1" => "content1",
"field2" => "content2",
"field3" => "content3"
}
I have try with 4 fields, it also works.
Please note that the event in the ruby code is logstash event. You can use it to get all your event field such as message, #timestamp etc.
Enjoy it!!!
I found another way using regex:
ruby {
code => "
fields = event['message'].scan(/(?<=\[)\w+: .*?(?=\](?: |$))/)
for field in fields
field = field.split(': ')
event[field[0]] = field[1]
end
"
}
I know that this is an old post, but I just came across it today, so I thought I'd offer an alternate method. Please note that, as a rule, I would almost always use a ruby filter, as suggested in either of the two previous answers. However, I thought I would offer this as an alternative.
If there is a fixed number of fields or a maximum number of fields (i.e., there may be fewer than three fields, but there will never be more than three fields), this can be done with a combination of grok and mutate filters, as well.
# Test message is: `[fieldname: value]`
# Store values in [#metadata] so we don't have to explicitly delete them.
grok {
match => {
"[message]" => [
"\[%{DATA:[#metadata][_field_name_01]}:\s+%{DATA:[#metadata][_field_value_01]}\]( \[%{DATA:[#metadata][_field_name_02]}:\s+%{DATA:[#metadata][_field_value_02]}\])?( \[%{DATA:[#metadata][_field_name_03]}:\s+%{DATA:[#metadata][_field_value_03]}\])?"
]
}
}
# Rename the fieldname, value combinations. I.e., if the following data is in the message:
#
# [foo: bar]
#
# It will be saved in the elasticsearch output as:
#
# {"foo":"bar"}
#
mutate {
rename => {
"[#metadata][_field_value_01]" => "[%{[#metadata][_field_name_01]}]"
"[#metadata][_field_value_02]" => "[%{[#metadata][_field_name_02]}]"
"[#metadata][_field_value_03]" => "[%{[#metadata][_field_name_03]}]"
}
tag_on_failure => []
}
For those who may not be as familiar with regex, the captures in ()? are optional regex matches, meaning that if there is no match, the expression won't fail. The tag_on_failure => [] option in the mutate filter ensures that no error will be appended to tags if one of the renames fails because there was no data to capture and, as a result, there is no field to rename.