influxdb/CONTRIBUTING.md

# Contributing to InfluxDB v2

## Bug reports
Before you file an issue, please search existing issues in case it has already been filed, or perhaps even fixed.
If you file an issue, please include the following.
* Full details of your operating system (or distribution) e.g. `64bit Ubuntu 18.04`.
* The version of InfluxDB you are running
* Whether you installed it using a pre-built package, or built it from source.
* Clear steps to reproduce the issue described, if at all possible.

The easier it is for us to reproduce the problem, the easier it is for us to fix it.
If you have never written a bug report before, or if you want to brush up on your bug reporting skills, we recommend reading [Simon Tatham's essay "How to Report Bugs Effectively."](http://www.chiark.greenend.org.uk/~sgtatham/bugs.html)


Ideally, test cases would be in the form of `curl` commands.
For example:
```bash
# write data
curl -XPOST "http://localhost:8086/api/v2/write?org=YOUR_ORG&bucket=YOUR_BUCKET&precision=s" \
  --header "Authorization: Token YOURAUTHTOKEN" \
  --data-raw "mem,host=host1 used_percent=23.43234543 1556896326"

# query data
# Bug: expected it to return no data, but data comes back.
curl http://localhost:8086/api/v2/query?org=my-org -XPOST -sS \
  -H 'Authorization: Token YOURAUTHTOKEN' \
  -H 'Accept: application/csv' \
  -H 'Content-type: application/vnd.flux' \
  -d 'from(bucket:"example-bucket")
    |> range(start:-1000h)
    |> group(columns:["_measurement"], mode:"by")
    |> sum()'
```

Test cases with `influx` commands are also helpful.
For example:
```
# write data
influx write -o YOUR_ORG -b YOUR_BUCKET -p s -t YOURAUTHTOKEN \
  "mem,host=host1 used_percent=23.43234543 1556896326"

# query data
# Bug: expected it to return no data, but data comes back.
influx query -o YOUR_ORG -t YOURAUTHTOKEN 'from(bucket:"example-bucket")
  |> range(start:-1000h)
  |> group(columns:["_measurement"], mode:"by")
  |> sum()'
```

If you don't include a clear test case like this it will be very difficult for us to investigate your issue.
If writing the data is too difficult, please zip up your data directory and include a link to it in your bug report.

Please note that issues are *not the place to file general support requests* such as "how do I use collectd with InfluxDB?"
Questions of this nature should be sent to the [InfluxData Community](https://community.influxdata.com/), not filed as issues.

## Feature requests
We really like to receive feature requests as it helps us prioritize our work.
Please be clear about your requirements and goals, help us to understand what you would like to see added to InfluxD with examples and the reasons why it is important to you.
If you find your feature request already exists as a Github issue please indicate your support for that feature by using the "thumbs up" reaction.

## Contributing to the source code
InfluxDB requires Go 1.13 and uses Go modules.

You should read our [coding guide](https://github.com/influxdata/influxdb/blob/master/DEVELOPMENT.md), to understand better how to write code for InfluxDB.

## Submitting a pull request
To submit a pull request you should fork the InfluxDB repository, and make your change on a feature branch of your fork.
Then generate a pull request from your branch against *master* of the InfluxDB repository.
Include in your pull request details of your change -- the why *and* the how -- as well as the testing your performed.
Also, be sure to run the test suite with your change in place.
Changes that cause tests to fail cannot be merged.

There will usually be some back and forth as we finalize the change, but once that completes it may be merged.

To assist in review for the PR, please add the following to your pull request comment:

```md
- [ ] CHANGELOG.md updated
- [ ] Rebased/mergable
- [ ] Tests pass
- [ ] Sign [CLA](https://influxdata.com/community/cla/) (if not already signed)
```

## Security Vulnerability Reporting
InfluxData takes security and our users' trust very seriously.
If you believe you have found a security issue in any of our open source projects, please responsibly disclose it by contacting security@influxdata.com.
More details about security vulnerability reporting, including our GPG key, [can be found here](https://www.influxdata.com/how-to-report-security-vulnerabilities/).


## Signing the CLA

If you are going to be contributing back to InfluxDB please take a second to sign our CLA, which can be found [on our website](https://influxdata.com/community/cla/).

## Installing Go
InfluxDB requires Go 1.13.

At InfluxData we find `gvm`, a Go version manager, useful for installing Go.
For instructions on how to install it see [the gvm page on github](https://github.com/moovweb/gvm).

After installing gvm you can install and set the default go version by running the following:
```bash
$ gvm install go1.13
$ gvm use go1.13 --default
```

## Revision Control Systems
Go has the ability to import remote packages via revision control systems with the `go get` command.
To ensure that you can retrieve any remote package, be sure to install the following rcs software to your system.
Currently the project only depends on `git` and `bzr`.

 * [Install Git](http://git-scm.com/book/en/Getting-Started-Installing-Git)
 * [Install Bazaar](http://doc.bazaar.canonical.com/latest/en/user-guide/installing_bazaar.html)

## Getting & Building From Source

Since we depend on Go modules and use standard Go tooling, you can simply check out and build InfluxDB at your preferred location on your filesystem.

```bash
$ git clone git@github.com:influxdata/influxdb.git
```

## Building, Testing, and Installing

InfluxDB uses the standard Go tooling so the `build`, `install`, and `test` subcommands work as expected.
In the root of the InfluxDB git repository, you can simply run the following commands:

### Building

```bash
$ go build ./...
```

### Installing

```bash
$ go install ./...
```

### Testing

This project is built from various languages. To run test for all langauges and components use:

```bash
$ make test
```

To run tests for just the Javascript component use:

```bash
$ make test-js
```

To run tests for just the Go/Rust components use:

```bash
$ make test-go
```


## Generated Google Protobuf code

Most changes to the source do not require that the generated protocol buffer code be changed.
But if you need to modify the protocol buffer code, you'll first need to install the protocol buffers toolchain.

First install the [protocol buffer compiler](https://developers.google.com/protocol-buffers/
) 2.6.1 or later for your OS:

Then install the go plugins:

```bash
$ go get github.com/gogo/protobuf/proto
$ go get github.com/gogo/protobuf/protoc-gen-gogo
$ go get github.com/gogo/protobuf/gogoproto
```

Finally run, `go generate` after updating any `*.proto` file:

```bash
$ go generate ./...
```
**Troubleshooting**

If generating the protobuf code is failing for you, check each of the following:
* Ensure the protobuf library can be found. Make sure that `LD_LIBRARY_PATH` includes the directory in which the library `libprotoc.so` has been installed.
* Ensure the command `protoc-gen-gogo`, found in `GOPATH/bin`, is on your path. This can be done by adding `GOPATH/bin` to `PATH`.


## Generated Go Templates

The query engine requires optimized data structures for each data type so instead of writing each implementation several times we use templates.
_Do not change code that ends in a `.gen.go` extension!_
Instead you must edit the `.gen.go.tmpl` file that was used to generate it.

Once you've edited the template file, you'll need the [`tmpl`][tmpl] utility to generate the code:

```sh
$ go get github.com/benbjohnson/tmpl
```

Then you can regenerate all templates in the project:

```sh
$ go generate ./...
```

[tmpl]: https://github.com/benbjohnson/tmpl

## Profiling

When troubleshooting problems with CPU or memory the Go toolchain can be helpful.
You can start InfluxDB with CPU and memory profiling turned on.
For example:

```bash
# start influx with profiling

$ ./influxd -cpuprofile influxdcpu.prof -memprof influxdmem.prof

# run queries, writes, whatever you're testing
# Quit out of influxd and influxd.prof will then be written.
# open up pprof to examine the profiling data.

$ go tool pprof ./influxd influxd.prof

# once inside run "web", opens up browser with the CPU graph
# can also run "web <function name>" to zoom in. Or "list <function name>" to see specific lines
```
Note that when you pass the binary to `go tool pprof` *you must specify the path to the binary*.

If you are profiling benchmarks built with the `testing` package, you may wish
to use the [`github.com/pkg/profile`](github.com/pkg/profile) package to limit
the code being profiled:

```go
func BenchmarkSomething(b *testing.B) {
  // do something intensive like fill database with data...
  defer profile.Start(profile.ProfilePath("/tmp"), profile.MemProfile).Stop()
  // do something that you want to profile...
}
```