[xen master] automation: implement (rootless) podman support in containerize

[patchbot@xxxxxxx]

commit 753ba5b37d6b547a7aa5f54fd498b56e02c80e2f
Author:     Dario Faggioli <dfaggioli@xxxxxxxx>
AuthorDate: Thu Apr 30 20:27:39 2020 +0200
Commit:     Wei Liu <wl@xxxxxxx>
CommitDate: Tue Jun 2 12:01:51 2020 +0000

    automation: implement (rootless) podman support in containerize
    
    Right now only docker is supported, when using the containerize script
    for building inside containers. Enable podman as well.
    
    Note that podman can be use in rootless mode too, but for that to work
    the files /etc/subuid and /etc/subgid must be properly configured.
    
    For instance:
    
    dario@localhost> cat /etc/subuid
    dario:100000:65536
    
    dario@localhost:> cat /etc/subgid
    dario:100000:65536
    
    Signed-off-by: Dario Faggioli <dfaggioli@xxxxxxxx>
    Acked-by: Wei Liu <wl@xxxxxxx>
    Release-acked-by: Paul Durrant <paul@xxxxxxx>
---
 automation/build/README.md      | 10 ++++++++++
 automation/scripts/containerize | 17 +++++++++++++----
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/automation/build/README.md b/automation/build/README.md
index 8cda2b65a5..e1fb3124de 100644
--- a/automation/build/README.md
+++ b/automation/build/README.md
@@ -34,6 +34,16 @@ the default shell.
 There are several environment variables which the containerize script
 understands.
 
+- DOCKED_CMD: Whether to use docker or podman for running the containers.
+  podman can be used as a regular user (rootless podman), but for that
+  to work, /etc/subuid and /etc/subgid needs to containe the proper
+  entries, for such user.
+  docker is the default, for running with podman, do:
+
+  ```
+  DOCKER_CMD=podman ./automation/scripts/containerize make
+  ```
+
 - CONTAINER: This overrides the container to use. For CentOS 7.2, use:
 
   ```
diff --git a/automation/scripts/containerize b/automation/scripts/containerize
index 22da711ace..a75d54566c 100755
--- a/automation/scripts/containerize
+++ b/automation/scripts/containerize
@@ -1,5 +1,14 @@
 #!/bin/bash
 
+#
+# DOCKER_CMD should be either `docker` or `podman`.
+#
+# if using (rootless) podman, remember to set /etc/subuid
+# and /etc/subgid.
+#
+docker_cmd=${DOCKER_CMD:-"docker"}
+[ "$DOCKER_CMD" = "podman" ] && userns_podman="--userns=keep-id"
+
 einfo() {
     echo "$*" >&2
 }
@@ -32,7 +41,7 @@ esac
 # Use this variable to control whether root should be used
 case "_${CONTAINER_UID0}" in
     _1)   userarg= ;;
-    _0|_) userarg="-u $(id -u)" ;;
+    _0|_) userarg="-u $(id -u) $userns_podman" ;;
 esac
 
 # Save the commands for future use
@@ -50,8 +59,8 @@ tty -s && termint=t
 #
 if [[ "_${CONTAINER_NO_PULL}" != "_1" ]]; then
     einfo "*** Ensuring ${CONTAINER} is up to date"
-    docker pull ${CONTAINER} > /dev/null ||     \
-        die "Failed to update docker container"
+    ${docker_cmd} pull ${CONTAINER} > /dev/null ||     \
+        die "Failed to update container"
 fi
 
 if hash greadlink > /dev/null 2>&1; then
@@ -83,7 +92,7 @@ fi
 
 # Kick off Docker
 einfo "*** Launching container ..."
-exec docker run \
+exec ${docker_cmd} run \
     ${userarg} \
     ${SSH_AUTH_SOCK:+-e SSH_AUTH_SOCK="/tmp/ssh-agent/${SSH_AUTH_NAME}"} \
     -v "${CONTAINER_PATH}":/build:rw \
--
generated by git-patchbot for /home/xen/git/xen.git#master