|
| 1 | + |
| 2 | + |
| 3 | +# Podman Hello World image |
| 4 | + |
| 5 | +## Overview |
| 6 | + |
| 7 | +This directory contains the Containerfile and bash script necessary to create the |
| 8 | +"hello" podman image housed on quay.io under the Podman account in a public |
| 9 | +repository. The image is public and can be pulled without credentials. |
| 10 | + |
| 11 | +Using this image is helpful to: |
| 12 | + |
| 13 | + * Prove that basic Podman operations are working on the host. |
| 14 | + * Shows that the image was pulled from the quay.io container registry. |
| 15 | + * Container creation was successfully accomplished. (`podman ps -a`) |
| 16 | + * The created container was able to stream output to your terminal. |
| 17 | + |
| 18 | +## Directory Contents |
| 19 | + |
| 20 | +The contents of this directory contain: |
| 21 | + * ./Containerfile |
| 22 | + * ./podman_hello_world.c |
| 23 | + |
| 24 | +## Sample Usage |
| 25 | + |
| 26 | +To simply run the image: |
| 27 | + |
| 28 | +``` |
| 29 | +podman run quay.io/podman/hello |
| 30 | +
|
| 31 | +!... Hello Podman World ...! |
| 32 | +
|
| 33 | + .--"--. |
| 34 | + / - - \ |
| 35 | + / (O) (O) \ |
| 36 | + ~~~| -=(,Y,)=- | |
| 37 | + .---. /` \ |~~ |
| 38 | + ~/ o o \~~~~.----. ~~ |
| 39 | + | =(X)= |~ / (O (O) \ |
| 40 | + ~~~~~~~ ~| =(Y_)=- | |
| 41 | + ~~~~ ~~~| U |~~ |
| 42 | +
|
| 43 | +Project: https://github.com/containers/podman |
| 44 | +Website: https://podman.io |
| 45 | +Documents: https://docs.podman.io |
| 46 | +Twitter: @Podman_io |
| 47 | +``` |
| 48 | +To build the image yourself, copy the files from this directory into |
| 49 | +a local directory and issue these commands: |
| 50 | + |
| 51 | +``` |
| 52 | +podman build -t myhello . |
| 53 | +podman run myhello |
| 54 | +``` |
| 55 | + |
| 56 | +## Potential Issues: |
| 57 | + |
| 58 | +The image runs as a rootless user with the UID set to `1000`. |
| 59 | +If the /etc/subuid and /etch/subgid values are not set appropriately to run as a |
| 60 | +rootless user on the host, an error like this might be raised: |
| 61 | + |
| 62 | +``` |
| 63 | +Copying blob acab339ca1e8 done |
| 64 | +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 |
| 65 | +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 |
| 66 | +``` |
| 67 | + |
| 68 | +Please refer to this [blog post](https://www.redhat.com/sysadmin/rootless-podman) for further configuration information. |
| 69 | + |
| 70 | +## THANKS! |
| 71 | + |
| 72 | +Many Thanks to @afbjorklund for a great discussion during the |
| 73 | +first revision of this container image that resulted in moving |
| 74 | +from using bash to using C, and the ensuing changes to the |
| 75 | +Containerfile. |
| 76 | + |
| 77 | +Also many thanks to @mairin for the awesome ASCII art! |
0 commit comments