Installing

NATS philosophy is simplicity. Installation is just decompressing a zip file and copying the binary to an appropriate directory; you can also use your favorite package manager. Here's a list of different ways you can install or run NATS:

Installing via Docker

With Docker you can install the server easily without scattering binaries and other artifacts on your system. The only pre-requisite is to install docker.

> docker pull nats:latest
latest: Pulling from library/nats
Digest: sha256:0c98cdfc4332c0de539a064bfab502a24aae18ef7475ddcc7081331502327354
Status: Image is up to date for nats:latest
docker.io/library/nats:latest

To run NATS on Docker:

> docker run -p 4222:4222 -ti nats:latest
[1] 2019/05/24 15:42:58.228063 [INF] Starting nats-server version #.#.#
[1] 2019/05/24 15:42:58.228115 [INF] Git commit [#######]
[1] 2019/05/24 15:42:58.228201 [INF] Starting http monitor on 0.0.0.0:8222
[1] 2019/05/24 15:42:58.228740 [INF] Listening for client connections on 0.0.0.0:4222
[1] 2019/05/24 15:42:58.228765 [INF] Server is ready
[1] 2019/05/24 15:42:58.229003 [INF] Listening for route connections on 0.0.0.0:6222

More information on containerized NATS is available here.

Installing on Kubernetes with NATS Operator

Installation via the NATS Operator is beyond this tutorial. You can read about the NATS Operator here.

Installing via a Package Manager

On Windows:

> choco install nats-server

On Mac OS:

> brew install nats-server

To test your installation (provided the executable is visible to your shell):

> nats-server
[41634] 2019/05/13 09:42:11.745919 [INF] Starting nats-server version 2.0.0
[41634] 2019/05/13 09:42:11.746240 [INF] Listening for client connections on 0.0.0.0:4222
...
[41634] 2019/05/13 09:42:11.746249 [INF] Server id is NBNYNR4ZNTH4N2UQKSAAKBAFLDV3PZO4OUYONSUIQASTQT7BT4ZF6WX7
[41634] 2019/05/13 09:42:11.746252 [INF] Server is ready

Downloading a Release Build

You can find the latest release of nats-server here.

Download the zip file matching your systems architecture, and unzip. For this example, assuming version 2.0.0 of the server and a Linux AMD64:

> curl -L https://github.com/nats-io/nats-server/releases/download/v2.0.0/nats-server-v2.0.0-linux-amd64.zip -o nats-server.zip
> unzip nats-server.zip -d nats-server
Archive: nats-server.zip
creating: nats-server-v2.0.0-linux-amd64/
inflating: nats-server-v2.0.0-linux-amd64/README.md
inflating: nats-server-v2.0.0-linux-amd64/LICENSE
inflating: nats-server-v2.0.0-linux-amd64/nats-server
> sudo cp nats-server-v2.0.0-linux-amd64/nats-server /usr/bin

Installing From the Source

If you have Go installed, installing the binary is easy:

> GO111MODULE=on go get github.com/nats-io/nats-server/v2

This mechanism will install a build of master, which almost certainly will not be a released version. If you are a developer and want to play with the latest, this is the easiest way.

To test your installation (provided the $GOPATH/bin is set):

> nats-server
[41634] 2019/05/13 09:42:11.745919 [INF] Starting nats-server version 2.0.0
[41634] 2019/05/13 09:42:11.746240 [INF] Listening for client connections on 0.0.0.0:4222
...
[41634] 2019/05/13 09:42:11.746249 [INF] Server id is NBNYNR4ZNTH4N2UQKSAAKBAFLDV3PZO4OUYONSUIQASTQT7BT4ZF6WX7
[41634] 2019/05/13 09:42:11.746252 [INF] Server is ready

NATS v2 and Go Modules

If you are having issues when using the recent versions of NATS and Go modules such as:

go: github.com/nats-io/go-nats@v1.8.1: parsing go.mod: unexpected module path "github.com/nats-io/nats.go"
go: github.com/nats-io/go-nats-streaming@v0.5.0: parsing go.mod: unexpected module path "github.com/nats-io/stan.go"

To fix it:

1) Update your go.mod using the latest tags, for example for both NATS and NATS Streaming clients:

module github.com/wallyqs/hello-nats-go-mod
go 1.12
require (
github.com/nats-io/nats.go v1.8.1
github.com/nats-io/stan.go v0.5.0
)

Or if you want to import the NATS Server v2 to embed it, notice the /v2 after the nats-server module name. If that is not present, then go modules will not fetch it and would accidentally end up with 1.4.1 version of the server.

require (
github.com/nats-io/nats-server/v2 v2.0.0
github.com/nats-io/nats.go v1.8.1
)

If embedding both NATS Streaming and NATS Servers:

require (
github.com/nats-io/nats-server/v2 v2.0.0 // indirect
github.com/nats-io/nats-streaming-server v0.15.1
)

2) Next, update the imports within the repo:

find ./ -type f -name "*.go" -exec sed -i -e 's/github.com\/nats-io\/go-nats-streaming/github.com\/nats-io\/stan.go/g' {} \;
find ./ -type f -name "*.go" -exec sed -i -e 's/github.com\/nats-io\/go-nats/github.com\/nats-io\/nats.go/g' {} \;
find ./ -type f -name "*.go" -exec sed -i -e 's/github.com\/nats-io\/gnatsd/github.com\/nats-io\/nats-server\/v2/g' {} \;
find ./ -type f -name "*.go" -exec sed -i -e 's/github.com\/nats-io\/nats-server/github.com\/nats-io\/nats-server\/v2/g' {} \;

3) (Recommended) Run Go fmt as the rename will affect the proper ordering of the imports

Gotchas when using go get

When using go get to fetch the client, include an extra slash at the end of the repo. For example:

GO111MODULE=on go get github.com/nats-io/nats.go/@latest
GO111MODULE=on go get github.com/nats-io/nats.go/@v1.8.1

When trying to fetch the latest version of the server with go get, you have to add v2 at the end:

GO111MODULE=on go get github.com/nats-io/nats-server/v2@latest

Otherwise, go get will fetch the v1.4.1 version of the server, which is also named (gnatsd), the previous name for nats-server.

GO111MODULE=on go get github.com/nats-io/nats-server@latest
go: finding github.com/nats-io/gnatsd/server latest
go: finding golang.org/x/crypto/bcrypt latest
go: finding golang.org/x/crypto latest

In order to use an older tag, you will have to use the previous name (gnatsd) otherwise it will result in go mod parsing errors.

# OK
GO111MODULE=on go get github.com/nats-io/go-nats/@v1.7.2
# Not OK
GO111MODULE=on go get github.com/nats-io/nats.go/@v1.7.2
go: finding github.com/nats-io/nats.go v1.7.2
go: downloading github.com/nats-io/nats.go v1.7.2
go: extracting github.com/nats-io/nats.go v1.7.2
go: finding github.com/nats-io/go-nats/encoders/builtin latest
go: finding github.com/nats-io/go-nats/util latest
go: finding github.com/nats-io/go-nats/encoders latest
go: finding github.com/nats-io/go-nats v1.8.1
go: downloading github.com/nats-io/go-nats v1.8.1
go: extracting github.com/nats-io/go-nats v1.8.1
go: github.com/nats-io/go-nats@v1.8.1: parsing go.mod: unexpected module path "github.com/nats-io/nats.go"
go: error loading module requirements

For more information you can review the original issue in GitHub.