132 lines
9.2 KiB
Markdown
132 lines
9.2 KiB
Markdown
# Supported tags and respective `Dockerfile` links
|
|
|
|
- [`1.4.3`, `1.4` (*1.4/Dockerfile*)](https://github.com/docker-library/golang/blob/a4f3927494b48c7bdb6ea6edac8f89818853b45b/1.4/Dockerfile)
|
|
- [`1.4.3-onbuild`, `1.4-onbuild` (*1.4/onbuild/Dockerfile*)](https://github.com/docker-library/golang/blob/3427e88341de17a4d8921b859180a2649e1ab96e/1.4/onbuild/Dockerfile)
|
|
- [`1.4.3-cross`, `1.4-cross` (*1.4/cross/Dockerfile*)](https://github.com/docker-library/golang/blob/3427e88341de17a4d8921b859180a2649e1ab96e/1.4/cross/Dockerfile)
|
|
- [`1.4.3-wheezy`, `1.4-wheezy` (*1.4/wheezy/Dockerfile*)](https://github.com/docker-library/golang/blob/a4f3927494b48c7bdb6ea6edac8f89818853b45b/1.4/wheezy/Dockerfile)
|
|
- [`1.4.3-alpine`, `1.4-alpine` (*1.4/alpine/Dockerfile*)](https://github.com/docker-library/golang/blob/63a33bf151190592eaf0540dd4b7027a9ca13f9b/1.4/alpine/Dockerfile)
|
|
- [`1.5.2`, `1.5`, `1`, `latest` (*1.5/Dockerfile*)](https://github.com/docker-library/golang/blob/e5ff96b1ab32db028f608f89eacf2b827b85f69e/1.5/Dockerfile)
|
|
- [`1.5.2-onbuild`, `1.5-onbuild`, `1-onbuild`, `onbuild` (*1.5/onbuild/Dockerfile*)](https://github.com/docker-library/golang/blob/f1f65c0ab0097a5e3d079d5a74e2468e8d47563d/1.5/onbuild/Dockerfile)
|
|
- [`1.5.2-wheezy`, `1.5-wheezy`, `1-wheezy`, `wheezy` (*1.5/wheezy/Dockerfile*)](https://github.com/docker-library/golang/blob/e5ff96b1ab32db028f608f89eacf2b827b85f69e/1.5/wheezy/Dockerfile)
|
|
- [`1.5.2-alpine`, `1.5-alpine`, `1-alpine`, `alpine` (*1.5/alpine/Dockerfile*)](https://github.com/docker-library/golang/blob/e5ff96b1ab32db028f608f89eacf2b827b85f69e/1.5/alpine/Dockerfile)
|
|
|
|
For more information about this image and its history, please see [the relevant manifest file (`library/golang`)](https://github.com/docker-library/official-images/blob/master/library/golang). This image is updated via pull requests to [the `docker-library/official-images` GitHub repo](https://github.com/docker-library/official-images).
|
|
|
|
For detailed information about the virtual/transfer sizes and individual layers of each of the above supported tags, please see [the `golang/tag-details.md` file](https://github.com/docker-library/docs/blob/master/golang/tag-details.md) in [the `docker-library/docs` GitHub repo](https://github.com/docker-library/docs).
|
|
|
|
# What is Go?
|
|
|
|
Go (a.k.a., Golang) is a programming language first developed at Google. It is a statically-typed language with syntax loosely derived from C, but with additional features such as garbage collection, type safety, some dynamic-typing capabilities, additional built-in types (e.g., variable-length arrays and key-value maps), and a large standard library.
|
|
|
|
> [wikipedia.org/wiki/Go_(programming_language)](http://en.wikipedia.org/wiki/Go_%28programming_language%29)
|
|
|
|
|
|
|
|
# How to use this image
|
|
|
|
## Start a Go instance in your app
|
|
|
|
The most straightforward way to use this image is to use a Go container as both the build and runtime environment. In your `Dockerfile`, writing something along the lines of the following will compile and run your project:
|
|
|
|
```dockerfile
|
|
FROM golang:1.3-onbuild
|
|
```
|
|
|
|
This image includes multiple `ONBUILD` triggers which should cover most applications. The build will `COPY . /go/src/app`, `RUN go get -d -v`, and `RUN go install -v`.
|
|
|
|
This image also includes the `CMD ["app"]` instruction which is the default command when running the image without arguments.
|
|
|
|
You can then build and run the Docker image:
|
|
|
|
```console
|
|
$ docker build -t my-golang-app .
|
|
$ docker run -it --rm --name my-running-app my-golang-app
|
|
```
|
|
|
|
## Compile your app inside the Docker container
|
|
|
|
There may be occasions where it is not appropriate to run your app inside a container. To compile, but not run your app inside the Docker instance, you can write something like:
|
|
|
|
```console
|
|
$ docker run --rm -v "$PWD":/usr/src/myapp -w /usr/src/myapp golang:1.3 go build -v
|
|
```
|
|
|
|
This will add your current directory as a volume to the container, set the working directory to the volume, and run the command `go build` which will tell go to compile the project in the working directory and output the executable to `myapp`. Alternatively, if you have a `Makefile`, you can run the `make` command inside your container.
|
|
|
|
```console
|
|
$ docker run --rm -v "$PWD":/usr/src/myapp -w /usr/src/myapp golang:1.3 make
|
|
```
|
|
|
|
## Cross-compile your app inside the Docker container
|
|
|
|
If you need to compile your application for a platform other than `linux/amd64` (such as `windows/386`), this can be easily accomplished with the provided `cross` tags:
|
|
|
|
```console
|
|
$ docker run --rm -v "$PWD":/usr/src/myapp -w /usr/src/myapp -e GOOS=windows -e GOARCH=386 golang:1.3-cross go build -v
|
|
```
|
|
|
|
Alternatively, you can build for multiple platforms at once:
|
|
|
|
```console
|
|
$ docker run --rm -it -v "$PWD":/usr/src/myapp -w /usr/src/myapp golang:1.3-cross bash
|
|
$ for GOOS in darwin linux; do
|
|
> for GOARCH in 386 amd64; do
|
|
> go build -v -o myapp-$GOOS-$GOARCH
|
|
> done
|
|
> done
|
|
```
|
|
|
|
# Image Variants
|
|
|
|
The `golang` images come in many flavors, each designed for a specific use case.
|
|
|
|
## `golang:<version>`
|
|
|
|
This is the defacto image. If you are unsure about what your needs are, you probably want to use this one. It is designed to be used both as a throw away container (mount your source code and start the container to start your app), as well as the base to build other images off of.
|
|
|
|
## `golang:alpine`
|
|
|
|
This image is based on the popular [Alpine Linux project](http://alpinelinux.org), available in [the `alpine` official image](https://hub.docker.com/_/alpine). Alpine Linux is much smaller than most distribution base images (~5MB), and thus leads to much slimmer images in general.
|
|
|
|
This variant is highly recommended when final image size being as small as possible is desired. The only caveat to note is that it does use [musl libc](http://www.musl-libc.org) instead of [glibc and friends](http://www.etalabs.net/compare_libcs.html), so certain software might run into issues depending on the depth of their libc requirements. However, most software doesn't have an issue with this, so this variant is usually a very safe choice.
|
|
|
|
To minimize image size, it's uncommon for additional related tools to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile.
|
|
|
|
## `golang:onbuild`
|
|
|
|
This image makes building derivative images easier. For most use cases, creating a `Dockerfile` in the base of your project directory with the line `FROM golang:onbuild` will be enough to create a stand-alone image for your project.
|
|
|
|
While the `onbuild` variant is really useful for "getting off the ground running" (zero to Dockerized in a short period of time), it's not recommended for long-term usage within a project due to the lack of control over *when* the `ONBUILD` triggers fire (see also [`docker/docker#5714`](https://github.com/docker/docker/issues/5714), [`docker/docker#8240`](https://github.com/docker/docker/issues/8240), [`docker/docker#11917`](https://github.com/docker/docker/issues/11917)).
|
|
|
|
Once you've got a handle on how your project functions within Docker, you'll probably want to adjust your `Dockerfile` to inherit from a non-`onbuild` variant and copy the commands from the `onbuild` variant `Dockerfile` (moving the `ONBUILD` lines to the end and removing the `ONBUILD` keywords) into your own file so that you have tighter control over them and more transparency for yourself and others looking at your `Dockerfile` as to what it does. This also makes it easier to add additional requirements as time goes on (such as installing more packages before performing the previously-`ONBUILD` steps).
|
|
|
|
# License
|
|
|
|
View [license information](http://golang.org/LICENSE) for the software contained in this image.
|
|
|
|
# Supported Docker versions
|
|
|
|
This image is officially supported on Docker version 1.9.1.
|
|
|
|
Support for older versions (down to 1.6) is provided on a best-effort basis.
|
|
|
|
Please see [the Docker installation documentation](https://docs.docker.com/installation/) for details on how to upgrade your Docker daemon.
|
|
|
|
# User Feedback
|
|
|
|
## Documentation
|
|
|
|
Documentation for this image is stored in the [`golang/` directory](https://github.com/docker-library/docs/tree/master/golang) of the [`docker-library/docs` GitHub repo](https://github.com/docker-library/docs). Be sure to familiarize yourself with the [repository's `README.md` file](https://github.com/docker-library/docs/blob/master/README.md) before attempting a pull request.
|
|
|
|
## Issues
|
|
|
|
If you have any problems with or questions about this image, please contact us through a [GitHub issue](https://github.com/docker-library/golang/issues).
|
|
|
|
You can also reach many of the official image maintainers via the `#docker-library` IRC channel on [Freenode](https://freenode.net).
|
|
|
|
## Contributing
|
|
|
|
You are invited to contribute new features, fixes, or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.
|
|
|
|
Before you start to code, we recommend discussing your plans through a [GitHub issue](https://github.com/docker-library/golang/issues), especially for more ambitious contributions. This gives other contributors a chance to point you in the right direction, give you feedback on your design, and help you find out if someone else is working on the same thing.
|