podman + krun Support

CONTRIBUTING.md

@@ -67,3 +67,25 @@ Instead, pass `-D /local` to the [`runner.sh`](./runner.sh) script. This will
 mount the [`runner`](./runner/) directory into the microVM at `/local` and run
 the scripts that it contains from there instead. Which "entrypoint" to use is
 driven by the `RUNNER_ENTRYPOINT` variable in [`runner.sh`](./runner.sh).
+
+## Cleanup
+
+During development, many images might be created. To clean them away, you can
+run one of the following commands.
+
+When using the `krunvm` runtime:
+
+```bash
+buildah rmi $(buildah images --format '{{.ID}}')
+```
+
+When using `podman+krun`:
+
+```bash
+podman image rm $(podman images -q)
+```
+
+> [!WARNING]
+> These commands will remove all unused images on your system. Make sure you
+> don't need any of these images for other projects before running the cleanup.
+> You may need to rebuild images for this project after cleanup.

README.md

@@ -1,20 +1,24 @@
 # krunvm-based GitHub Runner(s)
 
 This project creates [self-hosted][self] (ephemeral) GitHub [runners] based on
-[krunvm]. [krunvm] creates [microVM]s, so the project enables fully isolated
+[libkrun]. [libkrun] creates [microVM]s, so the project enables fully isolated
 [runners] inside your infrastruture. MicroVMs boot fast, providing an experience
-close to running containers. [krunvm] creates and starts VMs based on the
+close to running containers. [libkrun] creates and starts VMs based on the
 multi-platform OCI images created for this project -- [ubuntu] (default) or
-[fedora].
+[fedora]. The project will create [microVM]s using either [krunvm] or
+[krun][crun] and [podman].
 
 ![Demo](./demo/demo.gif)
 
   [self]: https://docs.github.com/en/actions/hosting-your-own-runners/managing-self-hosted-runners/about-self-hosted-runners
   [runners]: https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners/about-github-hosted-runners
+  [libkrun]: https://github.com/containers/libkrun
   [krunvm]: https://github.com/containers/krunvm
   [microVM]: https://github.com/infracloudio/awesome-microvm
   [ubuntu]: https://github.com/efrecon/gh-runner-krunvm/pkgs/container/runner-krunvm-ubuntu
   [fedora]: https://github.com/efrecon/gh-runner-krunvm/pkgs/container/runner-krunvm-fedora
+  [crun]: https://github.com/containers/crun
+  [podman]: https://github.com/containers/podman
 
 ## Example
 
@@ -68,6 +72,7 @@ starting with `RUNNER_` will affect the behaviour of each [runner] (loop).
   critical software tools.
 + Good compatibility with the regular GitHub [runners]: same user ID, member of
   the `docker` group, password-less `sudo`, etc.
++ Supports both [krunvm] or the [krun][crun] runtime under [podman].
 + In theory, the main [ubuntu] and [fedora] images should be able to be used in
   more traditional container-based solutions -- perhaps [sysbox]? Reports and/or
   changes are welcome.
@@ -85,17 +90,20 @@ UNIX binary utilities. PRs are welcome to make the project work on MacOS, if it
 does not already.
 
 Apart from the standard UNIX binary utilities, you will need the following
-installed on the host. Installation is easiest on Fedora
+installed on the host. Installation is easiest on Fedora (see original [issue]
+for installation on older versions).
 
 + `curl`
 + `jq`
-+ `buildah`
-+ `krunvm` (and its [requirements])
++ A compatible runtime, i.e. either:
+  + `krun` and [`podman`][podman].
+  + `krunvm`, its [requirements] and `buildah`
 
-Note: You do not need `podman`.
+Note: When opting for `krunvm`, you do not need `podman`.
 
   [built]: ./.github/workflows/ci.yml
   [requirements]: https://github.com/containers/krunvm#installation
+  [issue]: https://github.com/efrecon/gh-runner-krunvm/issues/22
 
 ## GitHub Token
 
@@ -129,9 +137,9 @@ permissions.
 The [orchestrator] creates as many loops of ephemeral runners as requested.
 These loops are implemented as part of the [runner.sh][runner] script: the
 script will create a microVM based on the default image (see below), memory and
-vCPU requirement. It will then start that microVM using `krunvm` and that will
-start an (ephemeral) GitHub [runner][self]. As soon as a job has been executed
-on that runner, the microVM will end and a new will be created.
+vCPU requirement. It will then start that microVM using `krunvm` or `podman` and
+the VM will start an (ephemeral) GitHub [runner][self]. As soon as a job has
+been executed on that runner, the microVM will end and a new will be created.
 
 The OCI image is built in two parts:
 

lib/common.sh

@@ -51,9 +51,33 @@ usage() {
 }
 
 check_command() {
+  OPTIND=1
+  _hard=1
+  _warn=0
+  while getopts "sw-" _opt; do
+    case "$_opt" in
+      s) # Soft check, return an error code instead of exiting
+        _hard=0;;
+      w) # Print a warning when soft checking
+        _warn=1;;
+      -) # End of options, everything after is the command
+        break;;
+      ?)
+        error "$_opt is an unrecognised option";;
+    esac
+  done
+  shift $((OPTIND-1))
+  if [ -z "$1" ]; then
+    error "No command specified for checking"
+  fi
   trace "Checking $1 is an accessible command"
   if ! command -v "$1" >/dev/null 2>&1; then
-    error "Command not found: $1"
+    if is_true "$_hard"; then
+      error "Command not found: $1"
+    elif is_true "$_warn"; then
+      warn "Command not found: $1"
+    fi
+    return 1
   fi
 }
 
@@ -70,11 +94,6 @@ get_env() (
   fi
 )
 
-run_krunvm() {
-  debug "Running krunvm $*"
-  buildah unshare krunvm "$@"
-}
-
 tac() {
   awk '{ buffer[NR] = $0; } END { for(i=NR; i>0; i--) { print buffer[i] } }'
 }