make dependency require manual install

[newns] / newns

diff --git a/newns b/newns
index a3a932511a5b326967208bcd8f8f3b707d7beb0e..315c786062d45295994cbb82e85cc2559aaa6053 100755 (executable)
--- a/newns
+++ b/newns
@@ -16,20 +16,9 @@
 
 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
 
-tmp="$(readlink -f "${BASH_SOURCE}")"; script_dir="${tmp%/*}"
-if [[ ! $ERRHANDLE_PATH ]]; then
-  ERRHANDLE_PATH="$script_dir"/../errhandle/err
-fi
-if [[ -s $ERRHANDLE_PATH ]]; then
-  source $ERRHANDLE_PATH
-else
-  cd "$script_dir"
-  if ! wget -O err 'https://iankelling.org/git/?p=errhandle;a=blob_plain;f=err;hb=HEAD'; then
-    echo "$0: failed to get errhandle dependency" >&2
-    exit 1
-  fi
-  source err
-fi
+# https://savannah.nongnu.org/projects/bash-bear-trap/
+set -e; . /usr/local/lib/bash-bear; set +e
+
 
 usage() {
   cat <<EOF
@@ -72,13 +61,9 @@ files, so the mount namespace won't be needed for most use cases, and I
 will update the script to that the mount namespace not created unless a
 flag is passed in. Patch welcome to add that flag before then.
 
-This script has a dependency which you can download manually or it
-will be automatically downloaded into the same directory.
-It handles errors by printing stack trace and and cleaning up the namespaces.
-To download manually,
-git clone https://iankelling.org/git/errhandle
-into an adjacent directory, or
-export ERRHANDLE_PATH to point to the 'err' file in that repo.
+
+This script has a dependency
+https://savannah.nongnu.org/projects/bash-bear-trap/ . Search the script for "source" to see where to install or modify the  installed location.
 
 
 Background on this project (you can skip if you like):
@@ -176,25 +161,12 @@ dexec() { ip netns exec default "$@"; }
 mexec() { /usr/bin/nsenter --mount=/root/mount_namespaces/$nn "$@"; }
 
 
-# background: head -n1 is defensive. Not sure if there is some weird feature
-# for 2 routes to be 0/0.
-gateway_ifs=($(ipd route list exact 0/0 | head -n1| sed -r 's/.*dev\s+(\S+).*/\1/'))
-
-if [[ ! $gateway_ifs ]]; then
-  cat >&2 <<EOF
-$0: error: failed to find gateway interface. No output from:
-ipd route list exact 0/0 | head -n1| sed -r 's/.*dev\s+(\S+).*/\1/'
-output from "ipd route list exact 0/0":
-$(ipd route list exact 0/0)
-EOF
-  exit 1
-fi
-
 nat() {
-  for if in ${gateway_ifs[@]}; do
-    dexec iptables -t nat $1 POSTROUTING -o $if -j MASQUERADE \
-          -m comment --comment "systemd network namespace nat"
-  done
+  # note, in a previous commit i specified the output interface with -o,
+  # but that broke things when my gateway interface changed, and I can't
+  # see any advantage to it, so I removed it.
+  dexec iptables -t nat $1 POSTROUTING -s $network.0/24 -j MASQUERADE \
+        -m comment --comment "systemd network namespace nat"
 }
 
 # d = default
@@ -268,7 +240,7 @@ start() {
     ip -n $nn link set dev lo up
   fi
 
-  echo 1 | dexec dd of=/proc/sys/net/ipv4/ip_forward 2>/dev/null
+  echo 1 | dexec dd of=/proc/sys/net/ipv4/ip_forward status=none
 
   # docker helpfully changes the default FORWARD to drop...
   diptables-add FORWARD -i $v0 -j ACCEPT