<p>As I wrote this question I found a link to the original source code for these official images, which answered my questions:</p>

<p>For example, for official image <code>php:7.2-fpm</code>, the base image is: <a href="https://github.com/docker-library/php/blob/master/7.2/stretch/fpm/Dockerfile" rel="nofollow noreferrer">debian:stretch-slim</a> </p>

<p>And for official Apache image, <code>httpd</code> it's <a href="https://github.com/docker-library/httpd/blob/master/2.4/Dockerfile" rel="nofollow noreferrer">debian:buster-slim</a></p>

<p>So, to find out the distro upon which official images are based on, go here: <a href="https://github.com/docker-library" rel="nofollow noreferrer">https://github.com/docker-library</a></p>

<p>...and append your official image of interest to the URL.</p>

CC BY-SA 4.0
2019-10-21T20:24:12.387Z
2019-10-21T20:24:12.387Z
therobyouknow
<p>I already think I understand that docker containers "share" the same Linux kernel running on their host. But inside a particular docker container, the software stack could be a distro debian, alpine, centos or ubuntu and on top of that various other software components, such as a web server, database, language interpreter etc.</p>

<p>Indeed there are official images for such distros.</p>

<p>But there are also official images for Apache (<a href="https://hub.docker.com/_/httpd" rel="nofollow noreferrer">httpd</a>) and PHP (<a href="https://hub.docker.com/_/php" rel="nofollow noreferrer">php</a>)</p>

<p>My question is, how can I find out the default distro that these sit upon?</p>

<p>I ask, because for example, I've seen a Dockerfile which starts with:</p>

<p><code>FROM php:7.2-fpm</code> (which is one of the official PHP images)</p>

<p>Followed by:</p>

<pre><code>RUN apt-get update &amp;&amp; apt-get install -y \
        libfreetype6-dev \
        libjpeg62-turbo-dev \
        libpng-dev \
    &amp;&amp; docker-php-ext-install -j$(nproc) iconv \
    &amp;&amp; docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ \
    &amp;&amp; docker-php-ext-install -j$(nproc) gd
</code></pre>

<p>Source: <a href="https://hub.docker.com/_/php" rel="nofollow noreferrer">hub.docker.com/_/php</a> (see section "How to install more PHP extensions")</p>

<p>Also, what distro is used for the httpd (Apache) official image?</p>

CC BY-SA 4.0
2019-10-28T11:34:19.600Z
-1 downvote - why? The opinion might be that this might not be a valid question - but in any case the answer I give, provides the answer and suggests that a different question might be better to ask. I'd never downvote a question without giving a reason. In fact I've never downvoted a question, only provided constructive comments. Also credit me with giving my own answer (almost immediately after - benefit for all); I'm not a help vampire. Shame that the techie stereotype of limited communication skills is perpetuated by this negative score without reason. Thanks for your time reading though.
therobyouknow
<docker><dockerfile>
How to find the Linux distro used as the basis for an official docker image?
therobyouknow
# How to find the Linux distro used as the basis for an official docker image?

(Asked by: username_0 on 2019-10-21)

I already think I understand that docker containers "share" the same Linux kernel running on their host. But inside a particular docker container, the software stack could be a distro debian, alpine, centos or ubuntu and on top of that various other software components, such as a web server, database, language interpreter etc.
Indeed there are official images for such distros.
But there are also official images for Apache (httpd) and PHP (php)
My question is, how can I find out the default distro that these sit upon?
I ask, because for example, I've seen a Dockerfile which starts with:
FROM php:7.2-fpm (which is one of the official PHP images)
Followed by:
RUN apt-get update && apt-get install -y \
        libfreetype6-dev \
        libjpeg62-turbo-dev \
        libpng-dev \
    && docker-php-ext-install -j$(nproc) iconv \
    && docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ \
    && docker-php-ext-install -j$(nproc) gd

Source: hub.docker.com/_/php (see section "How to install more PHP extensions")
Also, what distro is used for the httpd (Apache) official image?

**Tags:** docker, dockerfile

> **Comments:**
> **username_0**: -1 downvote - why? The opinion might be that this might not be a valid question - but in any case the answer I give, provides the answer and suggests that a different question might be better to ask. I'd never downvote a question without giving a reason. In fact I've never downvoted a question, only provided constructive comments. Also credit me with giving my own answer (almost immediately after - benefit for all); I'm not a help vampire. Shame that the techie stereotype of limited communication skills is perpetuated by this negative score without reason. Thanks for your time reading though.  

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## 1 answers

### Answer by username_0 on 2019-10-21. Score: 1 | Accepted answer

As I wrote this question I found a link to the original source code for these official images, which answered my questions:

For example, for official image `php:7.2-fpm`, the base image is: [debian:stretch-slim](https://github.com/docker-library/php/blob/master/7.2/stretch/fpm/Dockerfile)

And for official Apache image, `httpd` it's [debian:buster-slim](https://github.com/docker-library/httpd/blob/master/2.4/Dockerfile)

So, to find out the distro upon which official images are based on, go here: <https://github.com/docker-library>

...and append your official image of interest to the URL.


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