Add support for external container

External containers are containers created outside of Podman.
For example Buildah and CRI-O Containers.

$ buildah from alpine
alpine-working-container
$ buildah run alpine-working-container touch /test
$ podman container exists --external alpine-working-container

$ podman container diff alpine-working-container
C /etc
A /test

Added --external flag to refer to external containers, rather then --storage.

Added --external for podman container exists and modified podman ps to use
--external rather then --storage.  It was felt that --storage would confuse
the user into thinking about changing the storage driver or options.

--storage is still supported through the use of aliases.

Finally podman contianer diff, does not require the --external flag, since it
there is little change of users making the mistake, and would just be a pain
for the user to remember the flag.

podman container exists --external is required because it could fool scripts
that rely on the existance of a Podman container, and there is a potential
for a partial deletion of a container, which could mess up existing users.

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

2 files changed, 50 insertions, 40 deletions

diff --git a/docs/source/markdown/podman-container-exists.1.md b/docs/source/markdown/podman-container-exists.1.md
index b8be07cb9..3d151cfce 100644
--- a/docs/source/markdown/podman-container-exists.1.md
+++ b/docs/source/markdown/podman-container-exists.1.md
@@ -4,7 +4,7 @@
 podman-container-exists - Check if a container exists in local storage
 
 ## SYNOPSIS
-**podman container exists** *container*
+**podman container exists** [*options*] *container*
 
 ## DESCRIPTION
 **podman container exists** checks if a container exists in local storage. The **ID** or **Name**
@@ -14,6 +14,9 @@ was an issue accessing the local storage.
 
 ## OPTIONS
 
+**--external**=*true|false*
+Check for external containers as well as Podman containers. These external containers are generally created via other container technology such as Buildah or CRI-O.
+
 **-h**, **--help**
 Print usage statement
 
@@ -33,6 +36,13 @@ $ echo $?
 1
 ```
 
+Check if an container called `ubi8-working-container` created via Buildah exists in local storage (the container does not actually exist).
+```
+$ podman container exists --external ubi8-working-container
+$ echo $?
+1
+```
+
 ## SEE ALSO
 podman(1)
 
diff --git a/docs/source/markdown/podman-ps.1.md b/docs/source/markdown/podman-ps.1.md
index 58d3358e5..90f147222 100644
--- a/docs/source/markdown/podman-ps.1.md
+++ b/docs/source/markdown/podman-ps.1.md
@@ -34,23 +34,33 @@ all the containers information.  By default it lists:
 
 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.
+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 `--external` option to see these external containers. External containers show the 'storage' status.
 
-**--pod**, **-p**
-
-Display the pods the containers are associated with
-
-**--storage**
+**--external**
 
 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**
+**--filter**, **-f**
 
-Display the extended information
+Filter what containers are shown in the output.
+Multiple filters can be given with multiple uses of the --filter flag.
+If multiple filters are given, only containers which match all of the given filters will be shown.
+Results will be drawn from all containers, regardless of whether --all was given.
 
-**--quiet**, **-q**
+Valid filters are listed below:
 
-Print the numeric IDs of the containers only
+| **Filter**      | **Description**                                                                  |
+| --------------- | -------------------------------------------------------------------------------- |
+| id              | [ID] Container's ID                                                              |
+| name            | [Name] Container's name                                                          |
+| label           | [Key] or [Key=Value] Label assigned to a container                               |
+| exited          | [Int] Container's exit code                                                      |
+| status          | [Status] Container's status: 'created', 'exited', 'paused', 'running', 'unknown' |
+| ancestor        | [ImageName] Image or descendant used to create container                         |
+| before          | [ID] or [Name] Containers created before this container                          |
+| since           | [ID] or [Name] Containers created since this container                           |
+| volume          | [VolumeName] or [MountpointDestination] Volume mounted in container              |
+| health          | [Status] healthy or unhealthy                                                    |
 
 **--format**=*format*
 
@@ -74,15 +84,9 @@ Valid placeholders for the Go template are listed below:
 | .Labels         | All the labels assigned to the container         |
 | .Mounts         | Volumes mounted in the container                 |
 
-**--sort**
-
-Sort by command, created, id, image, names, runningfor, size, or status",
-Note: Choosing size will sort by size of rootFs, not alphabetically like the rest of the options
-Default: created
-
-**--size**, **-s**
+**--help**, **-h**
 
-Display the total file size
+Print usage statement
 
 **--last**, **-n**
 
@@ -98,31 +102,27 @@ The latest option is not supported on the remote client.
 
 Display namespace information
 
-**--filter**, **-f**
+**--no-trunc**
 
-Filter what containers are shown in the output.
-Multiple filters can be given with multiple uses of the --filter flag.
-If multiple filters are given, only containers which match all of the given filters will be shown.
-Results will be drawn from all containers, regardless of whether --all was given.
+Display the extended information
 
-Valid filters are listed below:
+**--pod**, **-p**
 
-| **Filter**      | **Description**                                                                  |
-| --------------- | -------------------------------------------------------------------------------- |
-| id              | [ID] Container's ID                                                              |
-| name            | [Name] Container's name                                                          |
-| label           | [Key] or [Key=Value] Label assigned to a container                               |
-| exited          | [Int] Container's exit code                                                      |
-| status          | [Status] Container's status: 'created', 'exited', 'paused', 'running', 'unknown' |
-| ancestor        | [ImageName] Image or descendant used to create container                         |
-| before          | [ID] or [Name] Containers created before this container                          |
-| since           | [ID] or [Name] Containers created since this container                           |
-| volume          | [VolumeName] or [MountpointDestination] Volume mounted in container              |
-| health          | [Status] healthy or unhealthy                                                    |
+Display the pods the containers are associated with
 
-**--help**, **-h**
+**--quiet**, **-q**
 
-Print usage statement
+Print the numeric IDs of the containers only
+
+**--sort**
+
+Sort by command, created, id, image, names, runningfor, size, or status",
+Note: Choosing size will sort by size of rootFs, not alphabetically like the rest of the options
+Default: created
+
+**--size**, **-s**
+
+Display the total file size
 
 **--sync**
 
@@ -181,7 +181,7 @@ CONTAINER ID  IMAGE                            COMMAND    CREATED        STATUS
 ```
 
 ```
-$ podman ps --storage -a
+$ podman ps --external -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