even better documentation

diff --git a/newns b/newns
index 31f1b528c80bdab325c17631adf5c6245c745895..d6a1b08eb6bc7805cb5d3fadcc7f50b591b29ef2 100755 (executable)
--- a/newns
+++ b/newns
@@ -37,7 +37,7 @@ fi
 
 usage() {
     cat <<EOF
 
 usage() {
     cat <<EOF

-usage: ${0##*/} [OPTS] start|stop NETNS_NAME
+usage: ${0##*/} [OPTS] start|stop NS_NAME

 Setup new or systemd created network namespace with nat and mount namespace
 
 -c, --create    Create network namespace. For running outside systemd private net.
 Setup new or systemd created network namespace with nat and mount namespace
 
 -c, --create    Create network namespace. For running outside systemd private net.


@@ -54,7 +54,7 @@ Also create a named mount namespace under /root/mount_namespaces, so we
 can alter some system config for this namespace. Subsequent systemd
 command lines would be prefixed with:
 
 can alter some system config for this namespace. Subsequent systemd
 command lines would be prefixed with:
 

-/usr/bin/nsenter --mount=/root/mount_namespaces/NETNS_NAME
+/usr/bin/nsenter --mount=/root/mount_namespaces/NS_NAME

 
 Note, this means that they can't run as unpriveledged users, but once
 systemd 233 comes out, it will have a bind mount option from within unit
 
 Note, this means that they can't run as unpriveledged users, but once
 systemd 233 comes out, it will have a bind mount option from within unit


@@ -69,7 +69,7 @@ in a directory adjacent to the absolute, resolved directory this file is
 in.
 
 Background: "ip netns new ..." also does a mount namespace, then bind
 in.
 
 Background: "ip netns new ..." also does a mount namespace, then bind

-mounts each file/dir in /etc/netns/NETNS_NAME to /etc/NETNS_NAME. Note,
+mounts each file/dir in /etc/netns/NS_NAME to /etc/NS_NAME. Note,

 for openvpn having it's own resolv.conf by using it's user script which
 calls resolvconf, this doesn't help much. What we actually want to do is
 copy /run/resolvconf somehwere then bind mount it on top of
 for openvpn having it's own resolv.conf by using it's user script which
 calls resolvconf, this doesn't help much. What we actually want to do is
 copy /run/resolvconf somehwere then bind mount it on top of


@@ -82,7 +82,7 @@ EOF
 }
 
 
 }
 
 

-## begin arg parsing ##
+#### begin arg parsing ####

 create=false
 temp=$(getopt -l help,create hc "$@") || usage 1
 eval set -- "$temp"
 create=false
 temp=$(getopt -l help,create hc "$@") || usage 1
 eval set -- "$temp"


@@ -99,11 +99,10 @@ if (( $# != 2 )); then
 fi
 
 action=$1
 fi
 
 action=$1

-nn=$2 # network namespace / namespace name
-## end arg parsing ##
-
-## begin sanity checking ##
+nn=$2 # namespace name
+#### end arg parsing ####

 
 

+#### begin sanity checking ####

 install_error=false
 if ! type -p ip &>/dev/null; then
     echo "please install the iproute2 package"
 install_error=false
 if ! type -p ip &>/dev/null; then
     echo "please install the iproute2 package"


@@ -116,8 +115,7 @@ fi
 if $install_error; then
     exit 1
 fi
 if $install_error; then
     exit 1
 fi

-
-##   end sanity checking ##
+####   end sanity checking ####

 
 
 v0=veth0-$nn
 
 
 v0=veth0-$nn


@@ -128,10 +126,10 @@ if ! $create && [[ $(readlink /proc/self/ns/net) == "$(readlink /proc/1/ns/net)"
     create=true
 fi
 
     create=true
 fi
 

+# make the default network namespace be named

 target=/run/netns/default
 if [[ ! -e $target && ! -L $target ]]; then
     mkdir -p /run/netns
 target=/run/netns/default
 if [[ ! -e $target && ! -L $target ]]; then
     mkdir -p /run/netns

-    # make the default network namespace be named

     ln -s /proc/1/ns/net $target
 fi
 
     ln -s /proc/1/ns/net $target
 fi
 


@@ -146,7 +144,7 @@ fi
 dexec() { ip netns exec default "$@"; }
 
 
 dexec() { ip netns exec default "$@"; }
 
 

-# head -n1 is defensive. Not sure if there is some weird feature
+# background: head -n1 is defensive. Not sure if there is some weird feature

 # for 2 routes to be 0/0.
 gateway_if=$(ipd route list exact 0/0 | head -n1| sed -r 's/.*\s(\S+)\s*$/\1/')
 nat() { dexec iptables -t nat $1 POSTROUTING -o $gateway_if -j MASQUERADE \
 # for 2 routes to be 0/0.
 gateway_if=$(ipd route list exact 0/0 | head -n1| sed -r 's/.*\s(\S+)\s*$/\1/')
 nat() { dexec iptables -t nat $1 POSTROUTING -o $gateway_if -j MASQUERADE \


@@ -168,13 +166,13 @@ find_network() {
 }
 
 start() {
 }
 
 start() {

-

     find_network
     if ! $found; then
         echo "$0: error: no open network found"
         exit 1
     fi
 
     find_network
     if ! $found; then
         echo "$0: error: no open network found"
         exit 1
     fi
 

+    #### begin mount namespace setup ####

     mkdir -p /root/mount_namespaces
     if ! mountpoint /root/mount_namespaces >/dev/null; then
         mount --bind /root/mount_namespaces /root/mount_namespaces
     mkdir -p /root/mount_namespaces
     if ! mountpoint /root/mount_namespaces >/dev/null; then
         mount --bind /root/mount_namespaces /root/mount_namespaces


@@ -186,6 +184,7 @@ start() {
     if ! mountpoint /root/mount_namespaces/$nn >/dev/null; then
         unshare --mount=/root/mount_namespaces/$nn
     fi
     if ! mountpoint /root/mount_namespaces/$nn >/dev/null; then
         unshare --mount=/root/mount_namespaces/$nn
     fi

+    ####   end mount namespace setup ####

 
 
     if $create; then
 
 
     if $create; then


@@ -193,8 +192,6 @@ start() {
         ip -n $nn link set dev lo up
     fi
 
         ip -n $nn link set dev lo up
     fi
 

-
-

     echo 1 | dexec dd of=/proc/sys/net/ipv4/ip_forward 2>/dev/null
 
     _errcatch_cleanup=stop
     echo 1 | dexec dd of=/proc/sys/net/ipv4/ip_forward 2>/dev/null
 
     _errcatch_cleanup=stop