[04/23] docker: compact debian base

- install common/basic tools at once
- one-line Emdebian setup
- use eatmydata and remove apt cache to save space
- add bison and flex and git

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 tests/docker/dockerfiles/debian.docker | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

Philippe Mathieu-Daudé <f4bug@amsat.org> writes:

> - install common/basic tools at once
> - one-line Emdebian setup
> - use eatmydata and remove apt cache to save space
> - add bison and flex and git
>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  tests/docker/dockerfiles/debian.docker | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/tests/docker/dockerfiles/debian.docker b/tests/docker/dockerfiles/debian.docker
> index 52bd79938e..694f8d3b63 100644
> --- a/tests/docker/dockerfiles/debian.docker
> +++ b/tests/docker/dockerfiles/debian.docker
> @@ -9,17 +9,19 @@
>  #
>  FROM debian:stable-slim
>
> -# Setup some basic tools we need
> -RUN apt update
> -RUN apt install -yy curl aptitude
> -
> -# Setup Emdebian
> -RUN echo "deb http://emdebian.org/tools/debian/ jessie main" >> /etc/apt/sources.list
> -RUN curl http://emdebian.org/tools/debian/emdebian-toolchain-archive.key | apt-key add -
> +# Install some basic tools and common build utilities
> +RUN apt-get update && \
> +    DEBIAN_FRONTEND=noninteractive apt-get install -yy \
> +        eatmydata && \

I wonder if we should just use ENV instead to set DEBIAN_FRONTEND?

> +    DEBIAN_FRONTEND=noninteractive eatmydata apt-get install -y --no-install-recommends \
> +        curl aptitude \
> +        build-essential clang git \
> +        bison flex && \
> +    rm -rf /var/lib/apt

Use apt clean to do this.

>
>  # Duplicate deb line as deb-src
>  RUN cat /etc/apt/sources.list | sed "s/deb/deb-src/" >> /etc/apt/sources.list
>
> -# Install common build utilities
> -RUN apt update
> -RUN apt install -yy build-essential clang
> +# Setup Emdebian
> +RUN echo "deb http://emdebian.org/tools/debian/ jessie main" >> /etc/apt/sources.list && \
> +    curl http://emdebian.org/tools/debian/emdebian-toolchain-archive.key | apt-key add -

Why move this to the end? Once we have curl installed it would be nice
to do just one update step and have emdebian synced up in the base
image.


--
Alex Bennée

On 05/08/2017 08:04 AM, Alex Bennée wrote:
>
> Philippe Mathieu-Daudé <f4bug@amsat.org> writes:
>
>> - install common/basic tools at once
>> - one-line Emdebian setup
>> - use eatmydata and remove apt cache to save space
>> - add bison and flex and git
>>
>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> ---
>>  tests/docker/dockerfiles/debian.docker | 22 ++++++++++++----------
>>  1 file changed, 12 insertions(+), 10 deletions(-)
>>
>> diff --git a/tests/docker/dockerfiles/debian.docker b/tests/docker/dockerfiles/debian.docker
>> index 52bd79938e..694f8d3b63 100644
>> --- a/tests/docker/dockerfiles/debian.docker
>> +++ b/tests/docker/dockerfiles/debian.docker
>> @@ -9,17 +9,19 @@
>>  #
>>  FROM debian:stable-slim
>>
>> -# Setup some basic tools we need
>> -RUN apt update
>> -RUN apt install -yy curl aptitude
>> -
>> -# Setup Emdebian
>> -RUN echo "deb http://emdebian.org/tools/debian/ jessie main" >> /etc/apt/sources.list
>> -RUN curl http://emdebian.org/tools/debian/emdebian-toolchain-archive.key | apt-key add -
>> +# Install some basic tools and common build utilities
>> +RUN apt-get update && \
>> +    DEBIAN_FRONTEND=noninteractive apt-get install -yy \
>> +        eatmydata && \
>
> I wonder if we should just use ENV instead to set DEBIAN_FRONTEND?

In https://github.com/moby/moby/issues/4032#issuecomment-34597177 Tianon 
Gravi commented:

[...] setting it via ENV should be actively discouraged. [...]
The reason it's not a good default is that if I docker run -i -t ... 
bash, I'm now interactive, and this variable being set is very, very wrong.

>
>> +    DEBIAN_FRONTEND=noninteractive eatmydata apt-get install -y --no-install-recommends \
>> +        curl aptitude \
>> +        build-essential clang git \
>> +        bison flex && \
>> +    rm -rf /var/lib/apt
>
> Use apt clean to do this.

Ok.

>>
>>  # Duplicate deb line as deb-src
>>  RUN cat /etc/apt/sources.list | sed "s/deb/deb-src/" >> /etc/apt/sources.list
>>
>> -# Install common build utilities
>> -RUN apt update
>> -RUN apt install -yy build-essential clang
>> +# Setup Emdebian
>> +RUN echo "deb http://emdebian.org/tools/debian/ jessie main" >> /etc/apt/sources.list && \
>> +    curl http://emdebian.org/tools/debian/emdebian-toolchain-archive.key | apt-key add -
>
> Why move this to the end? Once we have curl installed it would be nice
> to do just one update step and have emdebian synced up in the base
> image.

In the first apt-get can install curl + build-essential clang in the 
same call, and there is no need to fetch emdebian.org index.

Using 'apt clean' at the end of a layer keeps smaller layer but the next 
layer have to call `apt-get update` again. Since this base image is used 
to cross-compile, the child image will have to call `dpkg 
--add-architecture ...` before fetching emdebian.org arch index again 
(apt-get update) to be able to install the `crossbuild-essential-$arch` 
package.
So there is no need to update right after adding this repo, the 'child' 
will do it (and have to do it).

>
> --
> Alex Bennée
>