Show c/storage (Buildah/CRI-O) containers in ps

The `podman ps --all` command will now show containers that
are under the control of other c/storage container systems and
the new `ps --storage` option will show only containers that are
in c/storage but are not controlled by libpod.

In the below examples, the '*working-container' entries were created
by Buildah.

```
podman ps -a
CONTAINER ID  IMAGE                             COMMAND  CREATED       STATUS                   PORTS  NAMES
9257ef8c786c  docker.io/library/busybox:latest  ls /etc  8 hours ago   Exited (0) 8 hours ago          gifted_jang
d302c81856da  docker.io/library/busybox:latest  buildah  30 hours ago  storage                         busybox-working-container
7a5a7b099d33  localhost/tom:latest              ls -alF  30 hours ago  Exited (0) 30 hours ago         hopeful_hellman
01d601fca090  localhost/tom:latest              ls -alf  30 hours ago  Exited (1) 30 hours ago         determined_panini
ee58f429ff26  localhost/tom:latest              buildah  33 hours ago  storage                         alpine-working-container

podman ps --external
CONTAINER ID  IMAGE                             COMMAND  CREATED       STATUS    PORTS  NAMES
d302c81856da  docker.io/library/busybox:latest  buildah  30 hours ago  external         busybox-working-container
ee58f429ff26  localhost/tom:latest              buildah  33 hours ago  external         alpine-working-container

```
Signed-off-by: TomSweeneyRedHat <tsweeney@redhat.com>
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

3 files changed, 24 insertions, 7 deletions

diff --git a/docs/source/markdown/podman-build.1.md b/docs/source/markdown/podman-build.1.md
index 6618df1b9..c38424a11 100644
--- a/docs/source/markdown/podman-build.1.md
+++ b/docs/source/markdown/podman-build.1.md
@@ -23,6 +23,8 @@ When the URL is an Containerfile, the Containerfile is downloaded to a temporary
 
 When a Git repository is set as the URL, the repository is cloned locally and then set as the context.
 
+NOTE: `podman build` uses code sourced from the `buildah` project to build container images.  This `buildah` code creates `buildah` containers for the `RUN` options in container storage. In certain situations, when the `podman build` crashes or users kill the `podman build` process, these external containers can be left in container storage. Use the `podman ps --all --storage` command to see these contaienrs. External containers can be removed with the `podman rm --storage` command.
+
 ## OPTIONS
 
 **--add-host**=*host*
@@ -804,7 +806,7 @@ If you are using a useradd command within a Containerfile with a large UID/GID,
 If you are using `useradd` within your build script, you should pass the `--no-log-init or -l` option to the `useradd` command.  This option tells useradd to stop creating the lastlog file.
 
 ## SEE ALSO
-podman(1), buildah(1), containers-registries.conf(5), crun(8), runc(8), useradd(8)
+podman(1), buildah(1), containers-registries.conf(5), crun(8), runc(8), useradd(8), podman-ps(1), podman-rm(1)
 
 ## HISTORY
 Aug 2020, Additional options and .dockerignore added by Dan Walsh <dwalsh@redhat.com>
diff --git a/docs/source/markdown/podman-ps.1.md b/docs/source/markdown/podman-ps.1.md
index 2f8112aab..58d3358e5 100644
--- a/docs/source/markdown/podman-ps.1.md
+++ b/docs/source/markdown/podman-ps.1.md
@@ -32,12 +32,18 @@ all the containers information.  By default it lists:
 
 **--all**, **-a**
 
-Show all the containers, default is only running containers
+Show all the containers created by Podman, default is only running containers.
+
+Note: Podman shares containers storage with other tools such as Buildah and CRI-O. In some cases these `external` containers might also exist in the same storage. Use the `--storage` option to see these external containers. External containers show the 'storage' status.
 
 **--pod**, **-p**
 
 Display the pods the containers are associated with
 
+**--storage**
+
+Display external containers that are not controlled by Podman but are stored in containers storage.  These external containers are generally created via other container technology such as Buildah or CRI-O and may depend on the same container images that Podman is also using.  External containers are denoted with either a 'buildah' or 'storage' in the COMMAND and STATUS column of the ps output. Only used with the --all option.
+
 **--no-trunc**
 
 Display the extended information
@@ -174,11 +180,20 @@ CONTAINER ID  IMAGE                            COMMAND    CREATED        STATUS
 
 ```
 
+```
+$ podman ps --storage -a
+CONTAINER ID  IMAGE                             COMMAND  CREATED      STATUS  PORTS  NAMES
+69ed779d8ef9f  redis:alpine  "redis-server"  25 hours ago  Created                   6379/tcp  k8s_container1_podsandbox1_redhat.test.crio_redhat-test-crio_1
+38a8a78596f9  docker.io/library/busybox:latest  buildah  2 hours ago  storage        busybox-working-container
+fd7b786b5c32  docker.io/library/alpine:latest   buildah  2 hours ago  storage        alpine-working-container
+f78620804e00  scratch                           buildah  2 hours ago  storage        working-container
+```
+
 ## ps
 Print a list of containers
 
 ## SEE ALSO
-podman(1)
+podman(1), buildah(1), crio(8)
 
 ## HISTORY
 August 2017, Originally compiled by Urvashi Mohnani <umohnani@redhat.com>
diff --git a/docs/source/markdown/podman-rm.1.md b/docs/source/markdown/podman-rm.1.md
index cddf06e3e..990af0cd1 100644
--- a/docs/source/markdown/podman-rm.1.md
+++ b/docs/source/markdown/podman-rm.1.md
@@ -45,9 +45,9 @@ The latest option is not supported on the remote client.
 
 **--storage**
 
-Remove the container from the storage library only.
-This is only possible with containers that are not present in libpod (cannot be seen by **podman ps**).
-It is used to remove containers from **podman build** and **buildah**, and orphan containers which were only partially removed by **podman rm**.
+Remove external containers from the storage library.
+This is only possible with containers that are not present in libpod can be seen by **podman ps --all --storage**).
+It is used to remove external containers from **podman build** and **buildah**, and orphan containers which were only partially removed by **podman rm**.
 The storage option conflicts with the **--all**, **--latest**, and **--volumes** options.
 
 **--volumes**, **-v**
@@ -96,7 +96,7 @@ $ podman rm -f --latest
   **125** The command fails for a reason other than container did not exist or is paused/running
 
 ## SEE ALSO
-podman(1), podman-image-rm(1)
+podman(1), podman-image-rm(1), podman-ps(1), podman-build(1)
 
 ## HISTORY
 August 2017, Originally compiled by Ryan Cole <rycole@redhat.com>