whalesay
Building and testing the whalesay docker demo
Notes
The whalesay example was created for docker training course.
Testing whalesay
https://hub.docker.com/r/docker/whalesay/
$ docker run docker/whalesay cowsay boo
Unable to find image 'docker/whalesay:latest' locally
latest: Pulling from docker/whalesay
Image docker.io/docker/whalesay:latest uses outdated schema1 manifest format. Please upgrade to a schema2 image for better future compatibility. More information at https://docs.docker.com/registry/spec/deprecated-schema-v1/
e190868d63f8: Already exists
909cd34c6fd7: Already exists
0b9bfabab7c1: Already exists
a3ed95caeb02: Already exists
00bf65475aba: Already exists
c57b6bcc83e3: Already exists
8978f6879e2f: Already exists
8eed3712d2cf: Already exists
Digest: sha256:178598e51a26abbc958b8a2e48825c90bc22e641de3d31e18aaf55f3258ba93b
Status: Downloaded newer image for docker/whalesay:latest
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< boo >
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this has pulled the image locally and left a stopped container after execution:
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
910b35e59bc1 docker/whalesay "cowsay boo" 34 seconds ago Exited (0) 33 seconds ago peaceful_borg
$ docker images docker/whalesay
REPOSITORY TAG IMAGE ID CREATED SIZE
docker/whalesay latest 6b362a9f73eb 5 years ago 247MB
cleaning up the contain and images
$ docker rm peaceful_borg
peaceful_borg
$ docker rmi docker/whalesay
Untagged: docker/whalesay:latest
Untagged: docker/whalesay@sha256:178598e51a26abbc958b8a2e48825c90bc22e641de3d31e18aaf55f3258ba93b
Deleted: sha256:6b362a9f73eb8c33b48c95f4fcce1b6637fc25646728cf7fb0679b2da273c3f4
The --rm (remove) flag can be used to automatically remove the container when it has exited:
$ docker run --rm docker/whalesay cowsay moo
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< moo >
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$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
$
Building a Derivative Image
The Dockerfile describes an image that layers a new command on the basic whalesay image
ARG FROM_REPO=docker/whalesay
ARG FROM_VERSION=latest
FROM ${FROM_REPO}:${FROM_VERSION}
RUN apt-get -y update && apt-get install -y fortunes
CMD /usr/games/fortune -a | cowsay
Building a new image:
docker build -t lck/whalesay .
Running it:
$ docker run --rm lck/whalesay
________________________________________
/ History, n.: \
| |
| Papa Hegel he say that all we learn |
| from history is that we |
| |
| learn nothing from history. I know |
| people who can't even learn from |
| |
| what happened this morning. Hegel must |
| have been taking the long view. |
| |
| -- Chad C. Mulligan, "The Hipcrime |
\ Vocab" /
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## ## ## ## ===
/""""""""""""""""___/ ===
~~~ {~~ ~~~~ ~~~ ~~~~ ~~ ~ / ===- ~~~
\______ o __/
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\____\______/
Cleaning up:
docker rmi lck/whalesay