cogniteev/echo repository overview

⁠cogniteev/echo Docker image

Docker automated-build providing a minimal Docker image for data container, compatible with Docker Compose.

⁠Rationale

Data-only container does not need Linux distribution. It just needs an executable to start the container.

tianon/true⁠ is the perfect Docker image for that. It provides /true executable and ... that's it!

Unfortunately [Docker Compose][https://github.com/docker/compose⁠] assumes that every container has the /bin/echo executable (see Compose issue #919⁠ on GitHub)

This image is meant to workaround this by providing this missing /bin/echo executable.

⁠Base Docker Image

• scratch

⁠Image content

• /bin/echo (written in C, not ASM ... yet)

⁠Installation

1. Install Docker⁠

2. Download automated build⁠: docker pull cogniteev/echo

⁠Basic Usage with Docker

1. Create a data container named data_container:

   sudo docker run -v /data --name data_container cogniteev/echo 
   

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2. Create a new container that:

   • mounts volume /data of data_container container
   • creates a file named /data/bar
   • is deleted once the container stops

   sudo echo foo |                         \
       docker run                          \
       --volumes-from data_container       \
       -i --rm  busybox                    \
       tee /data/bar
   

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3. Create a new container that:

   • mounts volume /data of data_container container
   • reads content of file /data/bar
   • is deleted once the container stops

   sudo docker run --volumes-from data_container --rm busybox cat /data/bar
   

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