Run update.sh

clojure/README.md

@@ -74,14 +74,6 @@ The `clojure` images come in many flavors, each designed for a specific use case
 
 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.
 
-## `clojure: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
-
-To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
-
 ## `clojure: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 clojure:onbuild` will be enough to create a stand-alone image for your project.
@@ -90,6 +82,14 @@ While the `onbuild` variant is really useful for "getting off the ground running
 
 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).
 
+## `clojure: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](http://clojure.org/license) for the software contained in this image.

django/README.md

@@ -62,6 +62,22 @@ $ docker run -it --rm --user "$(id -u):$(id -g)" -v "$PWD":/usr/src/app -w /usr/
 
 This will create a sub-directory named `mysite` inside your current directory.
 
+# Image Variants
+
+The `django` images come in many flavors, each designed for a specific use case.
+
+## `django:<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.
+
+## `django: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 django: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](https://github.com/django/django/blob/master/LICENSE) for the software contained in this image.

elixir/README.md

@@ -59,6 +59,10 @@ The `elixir` images come in many flavors, each designed for a specific use case.
 
 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.
 
+## `elixir:slim`
+
+This image does not contain the common packages contained in the default tag and only contains the minimal packages needed to run `elixir`. Unless you are working in an environment where *only* the elixir image will be deployed and you have space constraints, we highly recommend using the default image of this repository.
+
 ## `elixir: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 elixir:onbuild` will be enough to create a stand-alone image for your project.
@@ -67,10 +71,6 @@ While the `onbuild` variant is really useful for "getting off the ground running
 
 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).
 
-## `elixir:slim`
-
-This image does not contain the common packages contained in the default tag and only contains the minimal packages needed to run `elixir`. Unless you are working in an environment where *only* the elixir image will be deployed and you have space constraints, we highly recommend using the default image of this repository.
-
 # License
 
 Copyright 2012 Plataformatec

erlang/README.md

@@ -64,6 +64,26 @@ User switch command
 $ docker run -it --rm --name erlang-inst1 -v "$PWD":/usr/src/myapp -w /usr/src/myapp erlang escript your-escript.erl
 ```
 
+# Image Variants
+
+The `erlang` images come in many flavors, each designed for a specific use case.
+
+## `erlang:<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. This tag is based off of [`buildpack-deps`](https://registry.hub.docker.com/_/buildpack-deps/). `buildpack-deps` is designed for the average user of docker who has many images on their system. It, by design, has a large number of extremely common Debian packages. This reduces the number of packages that images that derive from it need to install, thus reducing the overall size of all images on your system.
+
+## `erlang:slim`
+
+This image does not contain the common packages contained in the default tag and only contains the minimal packages needed to run `erlang`. Unless you are working in an environment where *only* the erlang image will be deployed and you have space constraints, we highly recommend using the default image of this repository.
+
+## `erlang: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 erlang: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://www.erlang.org/about.html) for the software contained in this image.

golang/README.md

@@ -83,6 +83,30 @@ $ for GOOS in darwin linux; do
 > 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. This tag is based off of [`buildpack-deps`](https://registry.hub.docker.com/_/buildpack-deps/). `buildpack-deps` is designed for the average user of docker who has many images on their system. It, by design, has a large number of extremely common Debian packages. This reduces the number of packages that images that derive from it need to install, thus reducing the overall size of all images on your system.
+
+## `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).
+
+## `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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](http://golang.org/LICENSE) for the software contained in this image.

haproxy/README.md

@@ -72,6 +72,22 @@ $ docker kill -s HUP my-running-haproxy
 
 The entrypoint script in the image checks for running the command `haproxy` and replaces it with `haproxy-systemd-wrapper` from haproxy upstream which takes care of signal handling to do the graceful reload. Under the hood this uses the `-sf` option of haproxy so "there are two small windows of a few milliseconds each where it is possible that a few connection failures will be noticed during high loads" (see [Stopping and restarting HAProxy](http://www.haproxy.org/download/1.6/doc/management.txt)).
 
+# Image Variants
+
+The `haproxy` images come in many flavors, each designed for a specific use case.
+
+## `haproxy:<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.
+
+## `haproxy: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](http://www.haproxy.org/download/1.5/doc/LICENSE) for the software contained in this image.

influxdb/README.md

@@ -137,6 +137,22 @@ Navigate to [localhost:8083](http://localhost:8083) with your browser while runn
 
 See more about using the web administrator interface [here](https://docs.influxdata.com/influxdb/latest/tools/web_admin/).
 
+# Image Variants
+
+The `influxdb` images come in many flavors, each designed for a specific use case.
+
+## `influxdb:<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. This tag is based off of [`buildpack-deps`](https://registry.hub.docker.com/_/buildpack-deps/). `buildpack-deps` is designed for the average user of docker who has many images on their system. It, by design, has a large number of extremely common Debian packages. This reduces the number of packages that images that derive from it need to install, thus reducing the overall size of all images on your system.
+
+## `influxdb: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](https://github.com/influxdata/influxdb/blob/master/LICENSE) for the software contained in this image.

java/README.md

@@ -71,6 +71,22 @@ As all of the major upstream Linux distributions are unwilling to redistribute O
 -	CentOS requires users to go and download the rpm provided by Oracle at java.com and thus accept the Oracle license ([wiki.centos.org](https://wiki.centos.org/HowTos/JavaRuntimeEnvironment)).
 -	RedHat provides instructions to add a repo that is maintained by Oracle ([access.redhat.com](https://access.redhat.com/solutions/732883)).
 
+# Image Variants
+
+The `java` images come in many flavors, each designed for a specific use case.
+
+## `java:<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. This tag is based off of [`buildpack-deps`](https://registry.hub.docker.com/_/buildpack-deps/). `buildpack-deps` is designed for the average user of docker who has many images on their system. It, by design, has a large number of extremely common Debian packages. This reduces the number of packages that images that derive from it need to install, thus reducing the overall size of all images on your system.
+
+## `java: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](http://openjdk.java.net/legal/gplv2+ce.html) for the software contained in this image.

jetty/README.md

@@ -107,6 +107,22 @@ If you would like the image to start immediately as user `jetty` instead of star
 $ docker run -d -u jetty jetty
 ```
 
+# Image Variants
+
+The `jetty` images come in many flavors, each designed for a specific use case.
+
+## `jetty:<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.
+
+## `jetty: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](http://eclipse.org/jetty/licenses.php) for the software contained in this image.

kapacitor/README.md

@@ -145,6 +145,22 @@ Then, from within the container, you can use the `kapacitor` command to interact
 
 See [this](https://docs.influxdata.com/kapacitor/latest/introduction/getting_started/) for a more detailed getting started guide with Kapacitor.
 
+# Image Variants
+
+The `kapacitor` images come in many flavors, each designed for a specific use case.
+
+## `kapacitor:<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. This tag is based off of [`buildpack-deps`](https://registry.hub.docker.com/_/buildpack-deps/). `buildpack-deps` is designed for the average user of docker who has many images on their system. It, by design, has a large number of extremely common Debian packages. This reduces the number of packages that images that derive from it need to install, thus reducing the overall size of all images on your system.
+
+## `kapacitor: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](https://github.com/influxdata/kapacitor/blob/master/LICENSE) for the software contained in this image.

memcached/README.md

@@ -41,6 +41,22 @@ This would set the memcache server to use 64 megabytes for storage.
 
 For infomation on configuring your memcached server, see the extensive [wiki](https://github.com/memcached/memcached/wiki).
 
+# Image Variants
+
+The `memcached` images come in many flavors, each designed for a specific use case.
+
+## `memcached:<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.
+
+## `memcached: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](https://github.com/memcached/memcached/blob/master/LICENSE) for the software contained in this image.

php/README.md

@@ -156,6 +156,22 @@ If you don't want to include a `Dockerfile` in your project, it is sufficient to
 $ docker run -d -p 80:80 --name my-apache-php-app -v "$PWD":/var/www/html php:5.6-apache
 ```
 
+# Image Variants
+
+The `php` images come in many flavors, each designed for a specific use case.
+
+## `php:<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.
+
+## `php: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](http://php.net/license/) for the software contained in this image.

pypy/README.md

@@ -62,6 +62,26 @@ or (again, if you need to use Python 2):
 $ docker run -it --rm --name my-running-script -v "$PWD":/usr/src/myapp -w /usr/src/myapp pypy:2 pypy your-daemon-or-script.py
 ```
 
+# Image Variants
+
+The `pypy` images come in many flavors, each designed for a specific use case.
+
+## `pypy:<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. This tag is based off of [`buildpack-deps`](https://registry.hub.docker.com/_/buildpack-deps/). `buildpack-deps` is designed for the average user of docker who has many images on their system. It, by design, has a large number of extremely common Debian packages. This reduces the number of packages that images that derive from it need to install, thus reducing the overall size of all images on your system.
+
+## `pypy:slim`
+
+This image does not contain the common packages contained in the default tag and only contains the minimal packages needed to run `pypy`. Unless you are working in an environment where *only* the pypy image will be deployed and you have space constraints, we highly recommend using the default image of this repository.
+
+## `pypy: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 pypy: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](https://bitbucket.org/pypy/pypy/src/c3ff0dd6252b6ba0d230f3624dbb4aab8973a1d0/LICENSE?at=default) for software contained in this image.

python/README.md

@@ -73,6 +73,34 @@ or (again, if you need to use Python 2):
 $ docker run -it --rm --name my-running-script -v "$PWD":/usr/src/myapp -w /usr/src/myapp python:2 python your-daemon-or-script.py
 ```
 
+# Image Variants
+
+The `python` images come in many flavors, each designed for a specific use case.
+
+## `python:<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. This tag is based off of [`buildpack-deps`](https://registry.hub.docker.com/_/buildpack-deps/). `buildpack-deps` is designed for the average user of docker who has many images on their system. It, by design, has a large number of extremely common Debian packages. This reduces the number of packages that images that derive from it need to install, thus reducing the overall size of all images on your system.
+
+## `python:slim`
+
+This image does not contain the common packages contained in the default tag and only contains the minimal packages needed to run `python`. Unless you are working in an environment where *only* the python image will be deployed and you have space constraints, we highly recommend using the default image of this repository.
+
+## `python: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
+## `python:onbuild`
+
+This image feeds your `requirements.txt` file automatically to `pip` in order to make building derivative images easier. For most use cases, creating a `Dockerfile` in the base of your project directory with the line `FROM python: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 for [Python 2](https://docs.python.org/2/license.html) and [Python 3](https://docs.python.org/3/license.html).

rails/README.md

@@ -63,6 +63,22 @@ $ docker run -it --rm --user "$(id -u):$(id -g)" -v "$PWD":/usr/src/app -w /usr/
 
 This will create a sub-directory named `webapp` inside your current directory.
 
+# Image Variants
+
+The `rails` images come in many flavors, each designed for a specific use case.
+
+## `rails:<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.
+
+## `rails: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 rails: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](https://github.com/rails/rails#license) for the software contained in this image.

redis/README.md

@@ -75,6 +75,22 @@ Where `/myredis/conf/` is a local directory containing your `redis.conf` file. U
 
 This variant is *not* a 32bit image (and will not run on 32bit hardware), but includes Redis compiled as a 32bit binary, especially for users who need the decreased memory requirements associated with that. See ["Using 32 bit instances"](http://redis.io/topics/memory-optimization#using-32-bit-instances) in the Redis documentation for more information.
 
+# Image Variants
+
+The `redis` images come in many flavors, each designed for a specific use case.
+
+## `redis:<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.
+
+## `redis: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](http://redis.io/topics/license) for the software contained in this image.

ruby/README.md

@@ -64,6 +64,34 @@ For many simple, single file projects, you may find it inconvenient to write a c
 $ docker run -it --rm --name my-running-script -v "$PWD":/usr/src/myapp -w /usr/src/myapp ruby:2.1 ruby your-daemon-or-script.rb
 ```
 
+# Image Variants
+
+The `ruby` images come in many flavors, each designed for a specific use case.
+
+## `ruby:<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. This tag is based off of [`buildpack-deps`](https://registry.hub.docker.com/_/buildpack-deps/). `buildpack-deps` is designed for the average user of docker who has many images on their system. It, by design, has a large number of extremely common Debian packages. This reduces the number of packages that images that derive from it need to install, thus reducing the overall size of all images on your system.
+
+## `ruby:slim`
+
+This image does not contain the common packages contained in the default tag and only contains the minimal packages needed to run `ruby`. Unless you are working in an environment where *only* the ruby image will be deployed and you have space constraints, we highly recommend using the default image of this repository.
+
+## `ruby: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
+## `ruby: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 ruby: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](https://www.ruby-lang.org/en/about/license.txt) for the software contained in this image.

telegraf/README.md

@@ -186,6 +186,22 @@ Check that the measurement `foo` is added in the DB.
 
 -	[Output Plugins](https://docs.influxdata.com/telegraf/latest/outputs/)
 
+# Image Variants
+
+The `telegraf` images come in many flavors, each designed for a specific use case.
+
+## `telegraf:<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. This tag is based off of [`buildpack-deps`](https://registry.hub.docker.com/_/buildpack-deps/). `buildpack-deps` is designed for the average user of docker who has many images on their system. It, by design, has a large number of extremely common Debian packages. This reduces the number of packages that images that derive from it need to install, thus reducing the overall size of all images on your system.
+
+## `telegraf: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 main 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. See [this Hacker News comment thread](https://news.ycombinator.com/item?id=10782897) for more discussion of the issues that might arise and some pro/con comparisons of using Alpine-based images.
+
+To minimize image size, it's uncommon for additional related tools (such as `git` or `bash`) to be included in Alpine-based images. Using this image as a base, add the things you need in your own Dockerfile (see the [`alpine` image description](https://hub.docker.com/_/alpine/) for examples of how to install packages if you are unfamiliar).
+
 # License
 
 View [license information](https://github.com/influxdata/telegraf/blob/master/LICENSE) for the software contained in this image.