start-container-docker.sh: Add --dryrun parameter.

This boolean selects whether to actually run commands in the
container.

If false, we keep the usual behaviour, and if true, the CONTAINER,
CONTAINER_RSH and container_exec helpers are modified to only print
what they would normally execute.

Change-Id: Ia85d528f1f4665c92c6415c053080d4a3c3e018d

1 files changed, 15 insertions, 4 deletions

diff --git a/start-container-docker.sh b/start-container-docker.sh
index be210d36..2f94d17b 100755
--- a/start-container-docker.sh
+++ b/start-container-docker.sh
@@ -15,10 +15,11 @@ set -e
 # - definition of ${session_host} and ${session_port}, can be used for
 #   a remote connexion to the container
 usage() {
-    echo "Usage: $0 [--arch container-arch] [--cp_file from[:to:owner:perms]] --distro flavour [--docker_opts opts] [--label label] [--newuser username:[uid]] [--node node] [--prefix prefix] [--session-host host] [--session-name name] [--task {build|test}] [--user user] [--weight weight]"
+    echo "Usage: $0 [--arch container-arch] [--cp_file from[:to:owner:perms]] --distro flavour [--docker_opts opts] [--dryrun true/false] [--label label] [--newuser username:[uid]] [--node node] [--prefix prefix] [--session-host host] [--session-name name] [--task {build|test}] [--user user] [--weight weight]"
     echo
     echo "  container-arch: architecture (eg: amd64, i386, arm64, armhf)"
     echo "  distro: distribution (eg: trusty)"
+    echo "  dryrun: boolean, just print commands if true"
     echo "  label: jenkins label; container is started on least-busy node; also sets container architecture"
     echo "  newuser: new user to create inside container, <username>[:<uid>] specification."
     echo "  node: jenkins node; container is started on host mapped to the node"
@@ -42,6 +43,7 @@ container_arch="default"
 cp_files=()
 distro="trusty-tcwg-tested"
 docker_opts=
+dryrun=false
 label=
 node=
 newuser=
@@ -75,6 +77,12 @@ do
 	    [ x"${docker_opts}" = x ] && usage
 	    shift 2
 	    ;;
+	--dryrun)
+	    dryrun=$2
+	    [ x${dryrun} = x ] && usage
+	    [ $dryrun != false ] && [ $dryrun != true ] && usage
+	    shift 2
+	    ;;
 	--label)
 	    label=$2
 	    [ x${label} = x ] && usage
@@ -127,6 +135,9 @@ do
     esac
 done
 
+dryruncmd=""
+[ $dryrun ] && dryruncmd="echo"
+
 if [ x"$node" = x"" -a x"$label" != x"" ]; then
     node=$(print_node_with_least_containers "$label")
     if [ x"$node" = x"" ]; then
@@ -279,7 +290,7 @@ exec 1>&3 2>&4
 
 cat <<EOF
 # v1 interface
-CONTAINER="ssh -p ${session_port} ${user}${session_host}"
+CONTAINER="${dryruncmd} ssh -p ${session_port} ${user}${session_host}"
 CONTAINER_CLEANUP="${CONTAINER_CLEANUP}"
 session_host=${session_host}
 session_port=${session_port}
@@ -289,7 +300,7 @@ session_port=${session_port}
 # Source jenkins-helpers.sh for remote_exec
 . "$(dirname "$(readlink -f "$0")")/jenkins-helpers.sh"
 
-${prefix}CONTAINER_RSH="ssh -p ${session_port} ${user}${session_host}"
+${prefix}CONTAINER_RSH="${dryruncmd} ssh -p ${session_port} ${user}${session_host}"
 ${prefix}container_cleanup ()
 {
   ${CONTAINER_CLEANUP}
@@ -300,7 +311,7 @@ ${prefix}container_stop ()
 }
 ${prefix}container_exec ()
 {
-  remote_exec "${user}${session_host}:${session_port}:\$(pwd)" "\$@"
+  $dryruncmd remote_exec "${user}${session_host}:${session_port}:\$(pwd)" "\$@"
 }
 
 ${prefix}container_host=${session_host}