* rounds nanoseconds boundaries to milliseconds

* convert also store query

* Added tail length limit to limit duration of live tailing of logs to 1 hour

* Some code refactoring suggested from PR review for live tailing duration limit

* Fixed error messages in live tailing of logs

* Fixed lint errors

* add benchmark for storage queries
* improve iterator to load only on next
* fix memory retained by lazy chunks
* reverse backward lazy iterator

Support for reading systemd journal entries has been added. 
promtail will look for a job in scrape_configs with a journal key 
to activate the journal target. 

If GOOS=linux and CGO_ENABLED=1, promtail will now require 
libsystemd headers to be available for building. If GOOS is not 
linux or CGO_ENABLED is not 1, journal support will be unavailable
and a log message will be printed warning the user that their config 
file has journal tailing configured without it being built into promtail. 

See docs/promtail-examples.md for a concrete example of 
using journal support. 

Other structural changes made: 

  1. Ability for checking if scrape.Config.ServiceDiscoveryConfig is 
     non-zero has been added. 

     This was chosen over making ServiceDiscoveryConfig a pointer
     as yaml.v2 cannot parse an inline struct into a pointer value. 

  2. Updated pipeline logger component name to journal_pipeline and
     file_pipeline for JournalTargetManager and FileTargetManager
     respectively.

  3. The positions file will now store positions as strings instead of 
     integers. Existing positions will be read in properly but written out 
     as strings the next time the positions file is saved. This is done to 
     be able to store the journal cursor, which is a string. The positions 
     API has been updated to support reading in the old integer values 
     and the new string values. 

use strconf.FormatFloat instead of fmt.Sprintf for converting floats to strings, this way we can eliminate non significant trailing zeros such that the float value 1 would be "1" as a string instead of "1.000000"

canary will suspend all operations on SIGINT but not exit, allowing you to shutdown the canary without it being restarted by docker/kubernetes
SIGTERM will shutdown everything and end the process

* Query label values and names are now fetched from the store.

A time range is now required by the /api/prom/label with a sane default (6 hours from now).

* fix http querystring and update doc

* update vendor

* rebased

removing entries.go as we are no longer using the custom Histogram for the log_entries_bytes histogram

changing the log length histogram to be a normal histogram with only a `path` label, also removing the label values when no longer tailing the file.  Following the same pattern we used for readBytes and totalBytes.

* Improvements in live tailing of logs

Instead of polling for new logs, a grpc stream is opened between ingester and querier to get live logs
Querier reconnects to disconnected or newly added ingesters

* Added more comments to code for live log tailing

* Some code refactoring in live log tailing

* handling delayfor in logcli, max delayfor to be 5 seconds

* some changes in tail response in live tailing

* Fixed issue with stopping ingesters gracefully when live tailing is being used

* Added tests for tailer in querier

* Live tailing made logql compatible, some code refactoring suggested in PR

Removing the pre-allocation of a buffer when serializing blocks, in most of my empirical testing we were using 9-10k out of the 32k allocated leaving about 2/3 of the buffer allocated and unused times the number of blocks per chunk, times the number of chunks kept in memory.  This was adding up to a fair amount of allocated but unused space.

* fix docker plugin ci

* use binary cache

* adds first version of docker driver

* without logrus and fixes some linter issue

* fix the driver and start a build system

* adds swarm label discovery

* Add documentation and more targets

* make the linter happy ❤️

* indent config.json

* with circleci steps for master and branch

* Review Feebacks

adding a list of received entries (acknowledged) to use for comparison against entries which were not expected so that we can report them as duplicates.

refactoring things so that the comparator can use the reader to make a direct query to loki to look for logs not received over the websocket  before reporting them as missing

* fix(promtail/targets): remove dependency on prometheus/relabel

`filetargetmanager.go` had a dependency on prometheus/relabel, a package that
has been removed in favor of prometheus/pkg/relabel.
This converts the code to the new package, to allow the prometheus vendor be
updated to master

* chore(vendor): update prometheus vendor

Updates prometheus vendor to current master, to add support for InitContainers
in kubernetes service discovery

* chore(vendor): do dep's homework

Gives dep hints on how to resolve the vendor so that it work

* fix(promtail/targets): non-nil check

Accidentally checked against the wrong labelSet, this one can never get nil

Signed-off-by: Xiang Dai <764524258@qq.com>

removed helm entry in scrape_config.sh because there doesn't seem to be anyway to make it work with new pipeline config

renaming `metric` stage to `metrics` as it defines multiple metrics, similar to labels stage which is also plural.
Adding a couple unit tests to regex and json stage to act as examples

cleaning up GoDoc
pipeline_name is now optional for matcher stage

refactored and improved some of the tests, each stage type should now have a test using actual YAML
A few TODO's remaining and some comment cleanup

metric test is still failing because of missing metrics when the counter is 0
added a lot of TODO's I need to go back and cleanup