containers: use podman or docker in unit-tests scripts

Detect if we have podman installed and use that in preference to docker.

Update the documentation to point out that docker always requires
running as root. With podman, the test can be run in a root or user
instance.

Closes #12286

containers/unit-tests/README.md

@@ -9,6 +9,10 @@ It assumes that the Cockpit source git checkout is available in `/source`. It
 will not modify that directory or take uncommitted changes into account, but it
 will re-use an already existing `node_modules/` directory.
 
+The scripts can use either podman (preferred) or docker. If you use docker, you
+need to run all commands as root. With podman the containers work as either user
+or root.
+
 ## Building
 
 The `build` script will build the `cockpit/unit-tests` and
@@ -29,17 +33,17 @@ to modify its behaviour:
 
 Some examples:
 
-    $ sudo ./start           # run the unit tests on amd64
+    $ ./start           # run the unit tests on amd64
 
-    $ sudo ./start CC=clang  # run the unit tests on amd64, compiled with clang
+    $ ./start CC=clang  # run the unit tests on amd64, compiled with clang
 
-    $ sudo ./start :i386     # run the unit tests on i386
+    $ ./start :i386     # run the unit tests on i386
 
 ## Debugging tests
 
 For interactive debugging, run a shell in the container:
 
-    $ sudo ./start shell     # start an interactive shell on i386
+    $ ./start shell     # start an interactive shell on i386
 
 You will find the cockpit source tree (from the host) mounted at `/source` in
 the container.
@@ -52,9 +56,9 @@ will checkout and build the source, but not run any tests.
 
 You can also attach to another container using the provided `exec` script.  For example:
 
-    $ sudo ./exec uname -a   # run a command as the "builder" user
+    $ ./exec uname -a   # run a command as the "builder" user
 
-    $ sudo ./exec --root     # start a shell as root
+    $ ./exec --root     # start a shell as root
 
 ## More Info
 

containers/unit-tests/build

@@ -2,7 +2,12 @@
 
 dir=$(dirname "$0")
 
-docker build --build-arg debian_arch=amd64 --build-arg personality=linux64 -t cockpit/unit-tests ${dir}
-docker tag  cockpit/unit-tests:latest docker.io/cockpit/unit-tests:latest
-docker build --build-arg debian_arch=i386 --build-arg personality=linux32 -t cockpit/unit-tests:i386 ${dir}
-docker tag  cockpit/unit-tests:i386 docker.io/cockpit/unit-tests:i386
+if test -z "${docker:=$(which podman || which docker || true)}"; then
+  echo 'Neither podman nor docker are installed'
+  exit 1
+fi
+
+$docker build --build-arg debian_arch=amd64 --build-arg personality=linux64 -t cockpit/unit-tests ${dir}
+$docker tag  cockpit/unit-tests:latest docker.io/cockpit/unit-tests:latest
+$docker build --build-arg debian_arch=i386 --build-arg personality=linux32 -t cockpit/unit-tests:i386 ${dir}
+$docker tag  cockpit/unit-tests:i386 docker.io/cockpit/unit-tests:i386

containers/unit-tests/exec

@@ -10,6 +10,8 @@ id=''
 
 while test $# -gt 0; do
   case "$1" in
+    --docker) docker="docker";;
+    --podman) docker="podman";;
     --root) args="$args -uroot";;
     --id=*) id="${1#--id=}";;
     -it) args="$args -it"; defaultargs='';;
@@ -20,8 +22,13 @@ while test $# -gt 0; do
   shift
 done
 
+if test -z "${docker:=$(which podman || which docker || true)}"; then
+  echo 'Neither podman nor docker are installed'
+  exit 1
+fi
+
 if [ -z "$id" ]; then
-  id="$(docker ps -qf "${filter}")"
+  id="$(${docker} ps -qf "${filter}")"
 
   if checkargs 2 $id; then :
   elif checkargs 1 $id; then
@@ -30,7 +37,7 @@ if [ -z "$id" ]; then
   else
     echo 'More than one running cockpit-unit/tests container:'
     echo
-    docker ps -f "${filter}" | sed -e 's/^/  /'
+    ${docker} ps -f "${filter}" | sed -e 's/^/  /'
     echo
     echo 'Use --id= to specify which one.'
     exit 1
@@ -42,5 +49,6 @@ if test $# -eq 0; then
   set -- $defaultcmd
 fi
 
+
 set -ex
-exec docker exec ${args} -- "${id}" /entrypoint "$@"
+exec ${docker} exec ${args} -- "${id}" /entrypoint "$@"

containers/unit-tests/start

@@ -7,6 +7,8 @@ cmd=''
 
 while test $# -gt 0; do
   case "$1" in
+    --docker) docker="docker";;
+    --podman) docker="podman";;
     CC=*) ccarg="--env=$1";;
     shell) flags=-it; cmd=/bin/bash;;
     :*) image=cockpit/unit-tests"$1";;
@@ -15,6 +17,11 @@ while test $# -gt 0; do
   shift
 done
 
+if test -z "${docker:=$(which podman || which docker || true)}"; then
+  echo 'Neither podman nor docker are installed'
+  exit 1
+fi
+
 set -ex
-exec docker run --shm-size=512M --volume "${top_srcdir}":/source:ro \
+exec ${docker} run --shm-size=512M --volume "${top_srcdir}":/source:ro \
        ${ccarg:+"$ccarg"} $flags -- "$image" $cmd