diff options
Diffstat (limited to 'contrib/hello/README.md')
| -rw-r--r-- | contrib/hello/README.md | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/contrib/hello/README.md b/contrib/hello/README.md new file mode 100644 index 000000000..528466f7b --- /dev/null +++ b/contrib/hello/README.md @@ -0,0 +1,77 @@ + + +# Podman Hello World image + +## Overview + +This directory contains the Containerfile and bash script necessary to create the +"hello" podman image housed on quay.io under the Podman account in a public +repository. The image is public and can be pulled without credentials. + +Using this image is helpful to: + + * Prove that basic Podman operations are working on the host. + * Shows that the image was pulled from the quay.io container registry. + * Container creation was successfully accomplished. (`podman ps -a`) + * The created container was able to stream output to your terminal. + +## Directory Contents + +The contents of this directory contain: + * ./Containerfile + * ./podman_hello_world.c + +## Sample Usage + +To simply run the image: + +``` +podman run quay.io/podman/hello + +!... Hello Podman World ...! + + .--"--. + / - - \ + / (O) (O) \ + ~~~| -=(,Y,)=- | + .---. /` \ |~~ + ~/ o o \~~~~.----. ~~ + | =(X)= |~ / (O (O) \ + ~~~~~~~ ~| =(Y_)=- | + ~~~~ ~~~| U |~~ + +Project: https://github.com/containers/podman +Website: https://podman.io +Documents: https://docs.podman.io +Twitter: @Podman_io +``` +To build the image yourself, copy the files from this directory into +a local directory and issue these commands: + +``` +podman build -t myhello . +podman run myhello +``` + +## Potential Issues: + +The image runs as a rootless user with the UID set to `1000`. +If the /etc/subuid and /etch/subgid values are not set appropriately to run as a +rootless user on the host, an error like this might be raised: + +``` +Copying blob acab339ca1e8 done +ERRO[0002] Error while applying layer: ApplyLayer exit status 1 stdout: stderr: potentially insufficient UIDs or GIDs available in user namespace (requested 0:12 for /var/spool/mail): Check /etc/subuid and /etc/subgid: lchown /var/spool/mail: invalid argument +Error: writing blob: adding layer with blob "sha256:ee0cde9de8a68f171a8c03b0e9954abf18576947e2f3187e84d8c31ccd8f6a09": ApplyLayer exit status 1 stdout: stderr: potentially insufficient UIDs or GIDs available in user namespace (requested 0:12 for /var/spool/mail): Check /etc/subuid and /etc/subgid: lchown /var/spool/mail: invalid argument +``` + +Please refer to this [blog post](https://www.redhat.com/sysadmin/rootless-podman) for further configuration information. + +## THANKS! + +Many Thanks to @afbjorklund for a great discussion during the +first revision of this container image that resulted in moving +from using bash to using C, and the ensuing changes to the +Containerfile. + +Also many thanks to @mairin for the awesome ASCII art! |