===== Deploy Containers=====

need to ensure you have everything installed

<code> dnf install container-tools </code>

use command **podman ** to interface with **runc** (the container engine)

some podman commands 
^  podman info  | gives configuration details for containers |
^  podman ps  | shows containers that are currently running for your user account  use **-a** to see even stopped containers|
^  podman image inspect  | used ti inspect an image tarfile  |
^  podman build	| Build a container image with a container file |
^  podman run  | Run a command in a new container|
^  podman images  | List images in local storage |
^  podman inspect  | Display configuration of a container, image, volume, network, or pod |
^  podman pull  | Download an image from a registry |
^  podman cp  |	Copy files or directories between a container and the local file system |
^  podman exec  |Execute a command in a running container |
^  podman rm  | Remove one or more containers |
^  podman rmi  | Remove one or more locally stored images |
^  podman search  | Search a registry for an image |

====Download a container Image from Registry===
 First check that the podman utility is configured to search and downlaod containers from the Registry needed

<code> podman info </code>

use <code>podman search image-wanted </code> to display a list of images on the configured registry

You can use the** skopeo inspect** command to examine different container image formats from a local directory or a remote registry without downloading the image

once you have the image you want you need to  download it 

<code>  podman pull registry.access.redhat.com/ubi8/python-38 </code>

use **podman images ** to verify

===Create container image from a container file===

you can use cat to see the containert file 

one you are ok with it use 
<code> podman build -t NAME:TAG DIR </code> 
^  NAME  | Name for the new image |
^  TAG  | Tag for the new image. If the tag is not specified, then the image is automatically tagged as latest |
^  DIR  | Path to the working directory. The container file must be in the working directory. If the working directory is the current directory, then you designate it by a dot (.). Use the -f flag to specify a different directory from the current one. |

once you have the container image you can then use it to run containers

===Running  Containers===

a container can be in several states:

^  Created  | A container that is created but is not started.|
^  Running  | A container that is running with its processes.  |
^  Stopped  | A container with its processes stopped.  |
^  Paused  | A container with its processes paused. Not supported for rootless containers. |
^  Deleted  | A container with its processes in a dead state. |

**NOTE** podman ps only shows the the running containers

To see all containers use
<code> podman ps -a </code>

You can create containers to run later
for example

<code>
[user@host ~]$ podman create --name python36 dd6ca291f097
c54c7ee281581c198cb96b07d78a0f94be083ae94dacbae69c05bd8cd354bbec
[user@host ~]$ podman ps
CONTAINER ID  IMAGE       COMMAND     CREATED     STATUS      PORTS       NAMES
[user@host ~]$ podman ps -a
CONTAINER ID  IMAGE                   COMMAND               CREATED        STATUS      PORTS       NAMES
c54c7ee28158  localhost/python36:1.0  /bin/bash -c slee...  5 seconds ago  Created                 python36 </code>

you can also start a container and reference the image if image is not there it will download it

<code>podman run -d  quay.io/rdacosta/my_httpd:lattest </code?

the **-d** staand for detached otherwise it binds container to the foreground

Once container is created you can start it 
example
<code>
[user@host ~]$ podman start python36
python36
[user@host ~]$ podman ps
CONTAINER ID  IMAGE                   COMMAND               CREATED        STATUS            PORTS       NAMES
c54c7ee28158  localhost/python36:1.0  /bin/bash -c slee...  6 minutes ago  Up 3 seconds ago              python36</code>

you can also interface with your container once it is running
**podman exec -it name-container process 
**
for example 
<code> podman exec -it romantic_aryavhata bash </code> this will open a bash prompt

====Troubleshooting====

You can check if a container is running or not with 
<code>podman ps -a </code>
if the container is listed as exited with code 1 then need to investigate a bit more

use
<code> podman container logs container_name</code>

you may need to pass extra variables for the container to start. Before you can do this you NEED to remove the failed container

<code>podman rm container_name <c/code>

then restart it with the -e option for example
<code>
[student@servera ~]$ podman run -d --name db_01 \
--network frontend \
-e MYSQL_USER=dev1 \
-e MYSQL_PASSWORD=devpass \
-e MYSQL_DATABASE=devdb \
-e MYSQL_ROOT_PASSWORD=redhat \
registry.lab.example.com/rhel8/mariadb-105 </code>