# Contributing to rqlite
rqlite is software, and it goes without saying it can always be improved. It's by no means finished -- issues are tracked, and I plan to develop this project further. Pull requests are welcome, though larger proposals should be discussed first. The design and implementation of rqlite is somewhat opinionated conservative however, so feature and design changes may be slow to become part of rqlite. 

rqlite can be compiled and executed on Linux, OSX, and Microsoft Windows.

## Google Group
You may also wish to check out the [rqlite Google Group](https://groups.google.com/forum/#!forum/rqlite).

## Clean commit histories
If you open a pull request, please ensure the commit history is clean. Squash the commits into logical blocks, perhaps a single commit if that makes sense. What you want to avoid is commits such as "WIP" and "fix test" in the history. This is so we keep history on master clean and straightforward.

## Third-party libraries
Please avoid using libaries other than those available in the standard library, unless necessary. This requirement is relaxed somewhat for software other than rqlite node software itself. To understand why this approach is taken, check out this [post](https://blog.gopheracademy.com/advent-2014/case-against-3pl/).

## Building rqlite
*Building rqlite requires Go 1.18 or later. [gvm](https://github.com/moovweb/gvm) is a great tool for installing and managing your versions of Go.*

One goal of rqlite is to keep the build process as simple. Download, build, and run rqlite like so (tested on 64-bit Kubuntu 16.04 and OSX):

```bash
mkdir rqlite # Or any directory of your choice.
cd rqlite/
export GOPATH=$PWD
mkdir -p src/github.com/rqlite
cd src/github.com/rqlite
git clone https://github.com/rqlite/rqlite.git
cd rqlite
go install ./...
$GOPATH/bin/rqlited ~/node.1
```
This starts a rqlite server listening on localhost, port 4001. This single node automatically becomes the leader.

To rebuild and run, perhaps after making some changes to the source, do something like the following:
```bash
cd $GOPATH/src/github.com/rqlite/rqlite
go install ./...
$GOPATH/bin/rqlited ~/node.1
```

### Linking behavior
Note that the above commands build a dynamically-linked version of `rqlited`. When officially released, `rqlited` statically links all its requirements e.g. `libc`.

### Raspberry Pi
The process outlined above will work for Linux, OSX, and Windows. For Raspberry Pi, check out [this issue](https://github.com/rqlite/rqlite/issues/340).

### Protobuf code generation
_This step is not necessary unless you are making changes to protobuf definitions._

Ensure you have the required tools installed, and that `GOPATH` is set.
```bash
go install google.golang.org/protobuf/cmd/protoc-gen-go
export GOBIN=$GOPATH/bin
export PATH=$PATH:$GOBIN
export DEST_DIR=$GOPATH/src

export SRC_DIR=$GOPATH/src/github.com/rqlite/rqlite/command
protoc -I=$SRC_DIR --proto_path=$GOPATH/src/github.com/rqlite/rqlite --go_out=$DEST_DIR $SRC_DIR/command.proto

export SRC_DIR=$GOPATH/src/github.com/rqlite/rqlite/cluster
protoc -I=$SRC_DIR --proto_path=$GOPATH/src/github.com/rqlite/rqlite --go_out=$DEST_DIR $SRC_DIR/message.proto
```

### Speeding up the build process
It can be rather slow to rebuild rqlite, due to the repeated compilation of the SQLite source code. You can compile and install the SQLite libary once, so subsequent builds are much faster. To do so, execute the following commands:
```bash
cd $GOPATH
go install github.com/rqlite/go-sqlite3
```

## Cloning a fork
If you wish to work with fork of rqlite, your own fork for example, you must still follow the directory structure above. But instead of cloning the main repo, instead clone your fork. You must fork the project if you want to contribute upstream.

Follow the steps below to work with a fork:

```bash
export GOPATH=$HOME/rqlite
mkdir -p $GOPATH/src/github.com/rqlite
cd $GOPATH/src/github.com/rqlite
git clone git@github.com:<your Github username>/rqlite
```

Retaining the directory structure `$GOPATH/src/github.com/rqlite` is necessary so that Go imports work correctly.

## Testing
Be sure to run the unit test suite before opening a pull request. An example test run is shown below.
```bash
$ cd $GOPATH/src/github.com/rqlite/rqlite
$ go test ./...
?       github.com/rqlite/rqlite       [no test files]
ok      github.com/rqlite/rqlite/auth  0.001s
?       github.com/rqlite/rqlite/cmd/rqlite    [no test files]
?       github.com/rqlite/rqlite/cmd/rqlited   [no test files]
ok      github.com/rqlite/rqlite/db    0.769s
ok      github.com/rqlite/rqlite/http  0.006s
ok      github.com/rqlite/rqlite/store 6.117s
ok      github.com/rqlite/rqlite/system_test   7.853s
```