Merge pull request #2431 from baude/remotereadme

podman remote-client readme

README.md

@@ -82,6 +82,9 @@ includes tables showing Docker commands and their Podman equivalent commands.
 **[Tutorials](docs/tutorials)**
 Tutorials on using Podman.
 
+**[Remote Client](remote_client.md)**
+A brief how-to on using the Podman remote-client.
+
 **[Release Notes](RELEASE_NOTES.md)**
 Release notes for recent Podman versions
 

remote_client.md

@@ -0,0 +1,77 @@
+# Podman remote-client tutorial
+
+## What is the remote-client
+
+First and foremost, the remote-client is under heavy development.  We are adding new
+commands and functions frequently.  We also are working on a rootless implementation that
+does not require privileged users.
+
+The purpose of the Podman remote-client is to allow users to interact with a Podman "backend"
+while on a separate client.  The command line interface of the remote client is exactly the
+same as the regular Podman commands with the exception of some flags being removed as they
+do not apply to the remote-client.
+
+## What you need
+To use the remote-client, you will need a binary for your client and a Podman "backend"; hereafter
+referred to as the Podman node.  In this context, a Podman node is a Linux system with Podman
+installed on it and the varlink service activated.  You will also need to be able to ssh into this
+system as a user with privileges to the varlink socket (more on this later).
+
+## Building the remote client
+At this time, the remote-client is not being packaged for any distribution.  It must be built from
+source.  To set up your build environment, see [Installation notes](install.md) and follow the
+section [Building from scratch](install.md#building-from-scratch).  Once you can successfully
+build the regular Podman binary, you can now build the remote-client.
+```
+$ make podman-remote
+```
+Like building the regular Podman, the resulting binary will be in the *bin* directory.  This is the binary
+you will run on the remote node later in the instructions.
+
+## Setting up the remote and Podman nodes
+
+To use the remote-client, you must perform some setup on both the remote and Podman nodes. In this case,
+the remote node refers to where the remote-client is being run; and the Podman node refers to where
+Podman and its storage reside.
+
+### Podman node setup
+The Podman node must have Podman (not the remote-client) installed as normal. If your system uses systemd,
+then simply start the Podman varlink socket.
+```
+$ sudo systemctl start io.podman.socket
+```
+
+If your system cannot use systemd, then you can manually establish the varlink socket with the Podman
+command:
+```
+$ sudo podman --log-level debug varlink --timeout 0  unix://run/podman/io.podman
+```
+
+### Required permissions
+For now, the remote-client requires that you be able to run a privileged Podman and have privileged ssh
+access to the remote system.  This limitation is being worked on.
+
+### Remote node setup
+
+#### Initiate an ssh session to the Podman node
+To use the remote client, we must establish an ssh connection to the Podman server.  We will also use
+that session to bind the remote varlink socket locally.
+
+```
+$ ssh -L 127.0.0.1:1234:/run/podman/io.podman root@remotehost
+```
+Note here we are binding the Podman socket to a local TCP socket on port 1234.
+
+#### Running the remote client
+With the ssh session established, we can now run the remote client in a different terminal window. You
+must inform Podman where to look for the bound socket you created in the previous step using an
+environment variable.
+
+```
+$ PODMAN_VARLINK_ADDRESS="tcp:127.0.0.1:1234" bin/podman-remote images
+REPOSITORY                     TAG      IMAGE ID       CREATED         SIZE
+docker.io/library/ubuntu       latest   47b19964fb50   2 weeks ago     90.7 MB
+docker.io/library/alpine       latest   caf27325b298   3 weeks ago     5.8 MB
+quay.io/cevich/gcloud_centos   latest   641dad61989a   5 weeks ago     489 MB
+k8s.gcr.io/pause               3.1      da86e6ba6ca1   14 months ago   747 kB
+```