Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.
LogCLI
LogCLI is the command-line interface to Grafana Loki. It facilitates running LogQL queries against a Loki instance.
Installation
Binary (Recommended)
Download the logcli
binary from the
Loki releases page.
Build LogCLI from source
Clone the Loki repository and build logcli
from source:
git clone https://github.com/grafana/loki.git
cd loki
make logcli
Optionally, move the binary into a directory that is part of your $PATH
.
cp cmd/logcli/logcli /usr/local/bin/logcli
Set up command completion
You can set up tab-completion for logcli
with one of the two options, depending on your shell:
For bash, add this to your
~/.bashrc
file:eval "$(logcli --completion-script-bash)"
For zsh, add this to your
~/.zshrc
file:eval "$(logcli --completion-script-zsh)"
LogCLI usage
Grafana Cloud example
If you are running on Grafana Cloud, use:
export LOKI_ADDR=https://logs-us-west1.grafana.net
export LOKI_USERNAME=<username>
export LOKI_PASSWORD=<password>
Otherwise you can point LogCLI to a local instance directly without needing a username and password:
export LOKI_ADDR=http://localhost:3100
Note: If you are running Loki behind a proxy server and you have authentication configured, you will also have to pass in LOKI_USERNAME and LOKI_PASSWORD, LOKI_BEARER_TOKEN or LOKI_BEARER_TOKEN_FILE accordingly.
$ logcli labels job
https://logs-dev-ops-tools1.grafana.net/api/prom/label/job/values
loki-ops/consul
loki-ops/loki-gw
...
$ logcli query '{job="loki-ops/consul"}'
https://logs-dev-ops-tools1.grafana.net/api/prom/query?query=%7Bjob%3D%22loki-ops%2Fconsul%22%7D&limit=30&start=1529928228&end=1529931828&direction=backward®exp=
Common labels: {job="loki-ops/consul", namespace="loki-ops"}
2018-06-25T12:52:09Z {instance="consul-8576459955-pl75w"} 2018/06/25 12:52:09 [INFO] raft: Snapshot to 475409 complete
2018-06-25T12:52:09Z {instance="consul-8576459955-pl75w"} 2018/06/25 12:52:09 [INFO] raft: Compacting logs from 456973 to 465169
...
$ logcli series -q --match='{namespace="loki",container_name="loki"}'
{app="loki", container_name="loki", controller_revision_hash="loki-57c9df47f4", filename="/var/log/pods/loki_loki-0_8ed03ded-bacb-4b13-a6fe-53a445a15887/loki/0.log", instance="loki-0", job="loki/loki", name="loki", namespace="loki", release="loki", statefulset_kubernetes_io_pod_name="loki-0", stream="stderr"}
Batched queries
LogCLI sends queries to Loki such that query results arrive in batches.
The --limit
option for a logcli query
command caps the quantity of
log lines for a single query.
When not set, --limit
defaults to 30.
The limit protects the user from overwhelming the system
for cases in which the specified query would have returned a large quantity
of log lines.
The limit also protects the user from unexpectedly large responses.
The quantity of log line results that arrive in each batch
is set by the --batch
option in a logcli query
command.
When not set, --batch
defaults to 1000.
Setting a --limit
value larger than the --batch
value causes the
requests from LogCLI to Loki to be batched.
Loki has a server-side limit that defaults to 5000 for the maximum quantity
of lines returned for a single query.
The batching of requests allows you to query for a results set that
is larger than the server-side limit,
as long as the --batch
value is less than the server limit.
Query metadata is output to stderr
for each batch.
Set the --quiet
option on the logcli query
command line to suppress
the output of the query metadata.
Configuration
Configuration values are considered in the following order (lowest to highest):
- Environment variables
- Command-line options
LogCLI command reference
The output of logcli help
:
usage: logcli [<flags>] <command> [<args> ...]
A command-line for loki.
Flags:
--help Show context-sensitive help (also try --help-long and
--help-man).
--version Show application version.
-q, --quiet Suppress query metadata
--stats Show query statistics
-o, --output=default Specify output mode [default, raw, jsonl]. raw
suppresses log labels and timestamp.
-z, --timezone=Local Specify the timezone to use when formatting output
timestamps [Local, UTC]
--cpuprofile="" Specify the location for writing a CPU profile.
--memprofile="" Specify the location for writing a memory profile.
--stdin Take input logs from stdin
--addr="http://localhost:3100"
Server address. Can also be set using LOKI_ADDR env
var.
--username="" Username for HTTP basic auth. Can also be set using
LOKI_USERNAME env var.
--password="" Password for HTTP basic auth. Can also be set using
LOKI_PASSWORD env var.
--ca-cert="" Path to the server Certificate Authority. Can also be
set using LOKI_CA_CERT_PATH env var.
--tls-skip-verify Server certificate TLS skip verify.
--cert="" Path to the client certificate. Can also be set using
LOKI_CLIENT_CERT_PATH env var.
--key="" Path to the client certificate key. Can also be set
using LOKI_CLIENT_KEY_PATH env var.
--org-id="" adds X-Scope-OrgID to API requests for representing
tenant ID. Useful for requesting tenant data when
bypassing an auth gateway.
Commands:
help [<command>...]
Show help.
query [<flags>] <query>
Run a LogQL query.
The "query" command is useful for querying for logs. Logs can be returned in
a few output modes:
raw: log line
default: log timestamp + log labels + log line
jsonl: JSON response from Loki API of log line
The output of the log can be specified with the "-o" flag, for example, "-o
raw" for the raw output format.
The "query" command will output extra information about the query and its
results, such as the API URL, set of common labels, and set of excluded
labels. This extra information can be suppressed with the --quiet flag.
By default we look over the last hour of data; use --since to modify or
provide specific start and end times with --from and --to respectively.
Notice that when using --from and --to then ensure to use RFC3339Nano time
format, but without timezone at the end. The local timezone will be added
automatically or if using --timezone flag.
Example:
logcli query
--timezone=UTC
--from="2021-01-19T10:00:00Z"
--to="2021-01-19T20:00:00Z"
--output=jsonl
'my-query'
The output is limited to 30 entries by default; use --limit to increase.
While "query" does support metrics queries, its output contains multiple
data points between the start and end query time. This output is used to
build graphs, similar to what is seen in the Grafana Explore graph view. If
you are querying metrics and just want the most recent data point (like what
is seen in the Grafana Explore table view), then you should use the
"instant-query" command instead.
instant-query [<flags>] <query>
Run an instant LogQL query.
The "instant-query" command is useful for evaluating a metric query for a
single point in time. This is equivalent to the Grafana Explore table view;
if you want a metrics query that is used to build a Grafana graph, you
should use the "query" command instead.
This command does not produce useful output when querying for log lines; you
should always use the "query" command when you are running log queries.
For more information about log queries and metric queries, refer to the
LogQL documentation:
https://grafana.com/docs/loki/latest/logql/
labels [<flags>] [<label>]
Find values for a given label.
series [<flags>] <matcher>
Run series query.
The "series" command will take the provided label matcher and return all the
log streams found in the time window.
It is possible to send an empty label matcher '{}' to return all streams.
Use the --analyze-labels flag to get a summary of the labels found in all
streams. This is helpful to find high cardinality labels.
LogCLI query command reference
The output of logcli help query
:
usage: logcli query [<flags>] <query>
Run a LogQL query.
The "query" command is useful for querying for logs. Logs can be returned in a few output modes:
raw: log line
default: log timestamp + log labels + log line
jsonl: JSON response from Loki API of log line
The output of the log can be specified with the "-o" flag, for example, "-o raw" for the raw output format.
The "query" command will output extra information about the query and its results, such as the API URL, set of common labels, and set of excluded labels. This extra information can be
suppressed with the --quiet flag.
By default we look over the last hour of data; use --since to modify or provide specific start and end times with --from and --to respectively.
Notice that when using --from and --to then ensure to use RFC3339Nano time format, but without timezone at the end. The local timezone will be added automatically or if using --timezone
flag.
Example:
logcli query
--timezone=UTC
--from="2021-01-19T10:00:00Z"
--to="2021-01-19T20:00:00Z"
--output=jsonl
'my-query'
The output is limited to 30 entries by default; use --limit to increase.
While "query" does support metrics queries, its output contains multiple data points between the start and end query time. This output is used to build graphs, similar to what is seen
in the Grafana Explore graph view. If you are querying metrics and just want the most recent data point (like what is seen in the Grafana Explore table view), then you should use the
"instant-query" command instead.
Parallelization:
You can download an unlimited number of logs in parallel, there are a few flags which control this behaviour:
--parallel-duration
--parallel-max-workers
--part-path-prefix
--overwrite-completed-parts
--merge-parts
--keep-parts
Refer to the help for each flag for details about what each of them do.
Example:
logcli query
--timezone=UTC
--from="2021-01-19T10:00:00Z"
--to="2021-01-19T20:00:00Z"
--output=jsonl
--parallel-duration="15m"
--parallel-max-workers="4"
--part-path-prefix="/tmp/my_query"
--merge-parts
'my-query'
This example will create a queue of jobs to execute, each being 15 minutes in duration. In this case, that means, for the 10-hour total duration, there will be forty 15-minute jobs.
The --limit flag is ignored.
It will start four workers, and they will each take a job to work on from the queue until all the jobs have been completed.
Each job will save a "part" file to the location specified by the --part-path-prefix. Different prefixes can be used to run multiple queries at the same time. The timestamp of the start and
end of the part is in the file name. While the part is being downloaded, the filename will end in ".part", when it is complete, the file will be renamed to remove this ".part" extension.
By default, if a completed part file is found, that part will not be downloaded again. This can be overridden with the --overwrite-completed-parts flag.
Part file example using the previous command, adding --keep-parts so they are not deleted:
Since we don't have the --forward flag, the parts will be downloaded in reverse. Two of the workers have finished their jobs (last two files), and have picked up the next jobs in the queue.
Running ls, this is what we should expect to see.
$ ls -1 /tmp/my_query* /tmp/my_query_20210119T183000_20210119T184500.part.tmp /tmp/my_query_20210119T184500_20210119T190000.part.tmp /tmp/my_query_20210119T190000_20210119T191500.part.tmp
/tmp/my_query_20210119T191500_20210119T193000.part.tmp /tmp/my_query_20210119T193000_20210119T194500.part /tmp/my_query_20210119T194500_20210119T200000.part
If you do not specify the --merge-parts flag, the part files will be downloaded, and logcli will exit, and you can process the files as you wish. With the flag specified, the part files
will be read in order, and the output printed to the terminal. The lines will be printed as soon as the next part is complete, you don't have to wait for all the parts to download before
getting output. The --merge-parts flag will remove the part files when it is done reading each of them. To change this, you can use the --keep-parts flag, and the part files will not be
removed.
Flags:
--help Show context-sensitive help (also try --help-long and --help-man).
--version Show application version.
-q, --quiet Suppress query metadata
--stats Show query statistics
-o, --output=default Specify output mode [default, raw, jsonl]. raw suppresses log labels and timestamp.
-z, --timezone=Local Specify the timezone to use when formatting output timestamps [Local, UTC]
--cpuprofile="" Specify the location for writing a CPU profile.
--memprofile="" Specify the location for writing a memory profile.
--stdin Take input logs from stdin
--addr="http://localhost:3100"
Server address. Can also be set using LOKI_ADDR env var.
--username="" Username for HTTP basic auth. Can also be set using LOKI_USERNAME env var.
--password="" Password for HTTP basic auth. Can also be set using LOKI_PASSWORD env var.
--ca-cert="" Path to the server Certificate Authority. Can also be set using LOKI_CA_CERT_PATH env var.
--tls-skip-verify Server certificate TLS skip verify. Can also be set using LOKI_TLS_SKIP_VERIFY env var.
--cert="" Path to the client certificate. Can also be set using LOKI_CLIENT_CERT_PATH env var.
--key="" Path to the client certificate key. Can also be set using LOKI_CLIENT_KEY_PATH env var.
--org-id="" adds X-Scope-OrgID to API requests for representing tenant ID. Useful for requesting tenant data when bypassing an auth gateway. Can also be set using
LOKI_ORG_ID env var.
--query-tags="" adds X-Query-Tags http header to API requests. This header value will be part of `metrics.go` statistics. Useful for tracking the query. Can also be set
using LOKI_QUERY_TAGS env var.
--bearer-token="" adds the Authorization header to API requests for authentication purposes. Can also be set using LOKI_BEARER_TOKEN env var.
--bearer-token-file="" adds the Authorization header to API requests for authentication purposes. Can also be set using LOKI_BEARER_TOKEN_FILE env var.
--retries=0 How many times to retry each query when getting an error response from Loki. Can also be set using LOKI_CLIENT_RETRIES env var.
--min-backoff=0 Minimum backoff time between retries. Can also be set using LOKI_CLIENT_MIN_BACKOFF env var.
--max-backoff=0 Maximum backoff time between retries. Can also be set using LOKI_CLIENT_MAX_BACKOFF env var.
--auth-header="Authorization"
The authorization header used. Can also be set using LOKI_AUTH_HEADER env var.
--proxy-url="" The http or https proxy to use when making requests. Can also be set using LOKI_HTTP_PROXY_URL env var.
--limit=30 Limit on number of entries to print. Setting it to 0 will fetch all entries.
--since=1h Lookback window.
--from=FROM Start looking for logs at this absolute time (inclusive)
--to=TO Stop looking for logs at this absolute time (exclusive)
--step=STEP Query resolution step width, for metric queries. Evaluate the query at the specified step over the time range.
--interval=INTERVAL Query interval, for log queries. Return entries at the specified interval, ignoring those between. **This parameter is experimental, please see Issue 1779**
--batch=1000 Query batch size to use until 'limit' is reached
--parallel-duration=1h Split the range into jobs of this length to download the logs in parallel. This will result in the logs being out of order. Use --part-path-prefix to create
a file per job to maintain ordering.
--parallel-max-workers=1 Max number of workers to start up for parallel jobs. A value of 1 will not create any parallel workers. When using parallel workers, limit is ignored.
--part-path-prefix=PART-PATH-PREFIX
When set, each server response will be saved to a file with this prefix. Creates files in the format: 'prefix-utc_start-utc_end.part'. Intended to be used
with the parallel-* flags so that you can combine the files to maintain ordering based on the filename. Default is to write to stdout.
--overwrite-completed-parts
Overwrites completed part files. This will download the range again, and replace the original completed part file. Default will skip a range if it's part
file is already downloaded.
--merge-parts Reads the part files in order and writes the output to stdout. Original part files will be deleted with this option.
--keep-parts Overrides the default behaviour of --merge-parts which will delete the part files once all the files have been read. This option will keep the part files.
--forward Scan forwards through logs.
--no-labels Do not print any labels
--exclude-label=EXCLUDE-LABEL ...
Exclude labels given the provided key during output.
--include-label=INCLUDE-LABEL ...
Include labels given the provided key during output.
--labels-length=0 Set a fixed padding to labels
--store-config="" Execute the current query using a configured storage from a given Loki configuration file.
--remote-schema Execute the current query using a remote schema retrieved using the configured storage in the given Loki configuration file.
--colored-output Show output with colored labels
-t, --tail Tail the logs
-f, --follow Alias for --tail
--delay-for=0 Delay in tailing by number of seconds to accumulate logs for re-ordering
Args:
<query> eg '{foo="bar",baz=~".*blip"} |~ ".*error.*"'
LogCLI labels command reference
The output of logcli help labels
:
usage: logcli labels [<flags>] [<label>]
Find values for a given label.
Flags:
--help Show context-sensitive help (also try --help-long and
--help-man).
--version Show application version.
-q, --quiet Suppress query metadata
--stats Show query statistics
-o, --output=default Specify output mode [default, raw, jsonl]. raw
suppresses log labels and timestamp.
-z, --timezone=Local Specify the timezone to use when formatting output
timestamps [Local, UTC]
--cpuprofile="" Specify the location for writing a CPU profile.
--memprofile="" Specify the location for writing a memory profile.
--stdin Take input logs from stdin
--addr="http://localhost:3100"
Server address. Can also be set using LOKI_ADDR env
var.
--username="" Username for HTTP basic auth. Can also be set using
LOKI_USERNAME env var.
--password="" Password for HTTP basic auth. Can also be set using
LOKI_PASSWORD env var.
--ca-cert="" Path to the server Certificate Authority. Can also be
set using LOKI_CA_CERT_PATH env var.
--tls-skip-verify Server certificate TLS skip verify.
--cert="" Path to the client certificate. Can also be set using
LOKI_CLIENT_CERT_PATH env var.
--key="" Path to the client certificate key. Can also be set
using LOKI_CLIENT_KEY_PATH env var.
--org-id="" adds X-Scope-OrgID to API requests for representing
tenant ID. Useful for requesting tenant data when
bypassing an auth gateway.
--since=1h Lookback window.
--from=FROM Start looking for labels at this absolute time
(inclusive)
--to=TO Stop looking for labels at this absolute time
(exclusive)
Args:
[<label>] The name of the label.
LogCLI series command reference
The output of logcli help series
:
usage: logcli series [<flags>] <matcher>
Run series query.
The "series" command will take the provided label matcher and return all the log
streams found in the time window.
It is possible to send an empty label matcher '{}' to return all streams.
Use the --analyze-labels flag to get a summary of the labels found in all
streams. This is helpful to find high cardinality labels.
Flags:
--help Show context-sensitive help (also try --help-long and
--help-man).
--version Show application version.
-q, --quiet Suppress query metadata
--stats Show query statistics
-o, --output=default Specify output mode [default, raw, jsonl]. raw
suppresses log labels and timestamp.
-z, --timezone=Local Specify the timezone to use when formatting output
timestamps [Local, UTC]
--cpuprofile="" Specify the location for writing a CPU profile.
--memprofile="" Specify the location for writing a memory profile.
--stdin Take input logs from stdin
--addr="http://localhost:3100"
Server address. Can also be set using LOKI_ADDR env
var.
--username="" Username for HTTP basic auth. Can also be set using
LOKI_USERNAME env var.
--password="" Password for HTTP basic auth. Can also be set using
LOKI_PASSWORD env var.
--ca-cert="" Path to the server Certificate Authority. Can also be
set using LOKI_CA_CERT_PATH env var.
--tls-skip-verify Server certificate TLS skip verify.
--cert="" Path to the client certificate. Can also be set using
LOKI_CLIENT_CERT_PATH env var.
--key="" Path to the client certificate key. Can also be set
using LOKI_CLIENT_KEY_PATH env var.
--org-id="" adds X-Scope-OrgID to API requests for representing
tenant ID. Useful for requesting tenant data when
bypassing an auth gateway.
--since=1h Lookback window.
--from=FROM Start looking for logs at this absolute time
(inclusive)
--to=TO Stop looking for logs at this absolute time (exclusive)
--analyze-labels Printout a summary of labels including count of label
value combinations, useful for debugging high
cardinality series
Args:
<matcher> eg '{foo="bar",baz=~".*blip"}'
LogCLI --stdin
usage
You can consume log lines from your stdin
instead of Loki servers.
Say you have log files in your local, and just want to do run some LogQL queries for that, --stdin
flag can help.
NOTE: Currently it doesn’t support any type of metric queries
You may have to use stdin
flag for several reasons
- Quick way to check and validate a LogQL expressions.
- Learn basics of LogQL with just Log files and
LogCLI
tool ( without needing set up Loki servers, Grafana etc.) - Easy discussion on public forums. Like Q&A, Share the LogQL expressions.
NOTES on Usage
--limits
flag doesn’t have any meaning when using--stdin
(use pager likeless
for that)- Be aware there are no labels when using
--stdin
- So stream selector in the query is optional e.g just
|="timeout"|logfmt|level="error"
is same as{foo="bar"}|="timeout|logfmt|level="error"
- So stream selector in the query is optional e.g just
Examples
- Line filter -
cat mylog.log | logcli --stdin query '|="too many open connections"'
- Label matcher -
echo 'msg="timeout happened" level="warning"' | logcli --stdin query '|logfmt|level="warning"'
- Different parsers (logfmt, json, pattern, regexp) -
cat mylog.log | logcli --stdin query '|pattern <ip> - - <_> "<method> <uri> <_>" <status> <size> <_> "<agent>" <_>'
- Line formatters -
cat mylog.log | logcli --stdin query '|logfmt|line_format "{{.query}} {{.duration}}"'