3 files changed, 71 insertions, 3 deletions
diff --git a/selftest/ns/mk_nsenter.sh b/selftest/ns/mk_nsenter.sh
new file mode 100755
index 00000000000..f175d6bae73
--- /dev/null
+++ b/selftest/ns/mk_nsenter.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+#
+# Helper script. If you want a 2nd shell that communicates with the testenv DC
+# you can use the nsenter command to change the namespace you're in. However,
+# this command is a bit unwieldly and changes depending on the testenv PID.
+# We can generate a helper script on the fly that abstracts all this
+# complexity, allowing you to use the same, simple command to change the
+# namespace that you're in, e.g.
+#   st/ad_dc/nsenter.sh
+
+pid=$1
+exports_file=$2
+
+# The basic command to enter the testenv's network namespace.
+# We enter the user namespace as well (as ourself, which is really the root
+# user for the namespace), otherwise we need sudo to make this work.
+nsenter_cmd="nsenter -t $pid --net --user --preserve-credentials"
+
+# By default, the nsenter command will just start a new shell in the namespace.
+# we use a wrapper helper script, which first loads all the environment
+# variables that are usually defined in selftest (and prints some basic help).
+helper_script="$(dirname $0)/nsenter-helper.sh $exports_file"
+
+# generate the dynamic script
+dyn_script="$(dirname $2)/nsenter.sh"
+echo "#!/bin/sh" > $dyn_script
+echo "$nsenter_cmd $helper_script" >> $dyn_script
+chmod 755 $dyn_script
+
+# return the script we created
+echo "$dyn_script"
+
diff --git a/selftest/ns/nsenter-helper.sh b/selftest/ns/nsenter-helper.sh
new file mode 100755
index 00000000000..f396ed4d98c
--- /dev/null
+++ b/selftest/ns/nsenter-helper.sh
@@ -0,0 +1,31 @@
+#!/bin/sh
+#
+# Helper script that gets run with nsenter to manually setup a secondary shell
+# session to a given namespace testenv. This basically just sets up the same
+# environment variables as you normally get with selftest, for convenience.
+
+if [ $# -lt 1 ] ; then
+    echo "Usage: $0 <exports-file>"
+    exit 1
+fi
+
+# we get passed a exports file with all the environment variables defined
+exports_file=$1
+
+# read the exports file so the new shell has appropriate variables setup
+# (we export rather than sourcing here so they get inherited by the subshell)
+while read -r line ; do
+    export $line
+    # dump them for the user too
+    echo $line
+done < $exports_file
+
+echo ""
+echo "Entered $NETBIOSNAME namespace, with above variables defined."
+echo "Use CTRL+D or exit to leave the namespace."
+echo ""
+
+# start a shell session in the new namespace
+$SHELL
+
+
diff --git a/selftest/ns/start_in_ns.sh b/selftest/ns/start_in_ns.sh
index 5831a0b2e24..f16767d545b 100755
--- a/selftest/ns/start_in_ns.sh
+++ b/selftest/ns/start_in_ns.sh
@@ -17,9 +17,14 @@ parent_pid=$3
 # The namespaces we use are anonymous, which means other processes would need
 # to use our PID to access the new namespace
 echo "-------------------------------------------------------------"
-echo "Created namespace for $NETBIOSNAME"
-echo "To communicate with this testenv, use: nsenter -t $$ --net sh"
-echo "To copy its environment variables, use: . $exports_file"
+echo "Created namespace for $NETBIOSNAME ($ENVNAME) PID $$"
+
+# generate a helper script if the developer wants to talk to this namespace
+# in another shell
+mk_nsenter_script="$(dirname $0)/mk_nsenter.sh"
+helper_script=$($mk_nsenter_script $$ $exports_file)
+
+echo "To communicate with this testenv, use: $helper_script"
 echo "-------------------------------------------------------------"
 
 # the rest of the args are the samba command to run