"Incorrect number of arguments" error while deploying using 'murder' - capistrano

Question

after i enter the peer command, it shows the following error:
** [out :: 172.23.99.7] Incorrect number of arguments
** [out :: 172.23.99.7]
** [out :: 172.23.99.7] Usage:
** [out :: 172.23.99.7] python murder_client.py peer/seed out.torrent OUT.OUT 127.0.0.1
** [out :: 172.23.99.7]
** [out :: 172.23.99.7] The last parameter is the local ip address, normally 10.x.x.x
** [out :: 172.23.99.7]
** [out :: 172.23.99.5] Incorrect number of arguments
** [out :: 172.23.99.5]
** [out :: 172.23.99.5] Usage:
** [out :: 172.23.99.5] python murder_client.py peer/seed out.torrent OUT.OUT 127.0.0.1
** [out :: 172.23.99.5]
** [out :: 172.23.99.5] The last parameter is the local ip address, normally 10.x.x.x
** [out :: 172.23.99.5]
** [out :: 172.23.98.78] Incorrect number of arguments
** [out :: 172.23.98.78]
** [out :: 172.23.98.78] Usage:
** [out :: 172.23.98.78] python murder_client.py peer/seed out.torrent OUT.OUT 127.0.0.1
** [out :: 172.23.98.78]
** [out :: 172.23.98.78] The last parameter is the local ip address, normally 10.x.x.x
** [out :: 172.23.98.78]
command finished
failed: "sh -c 'python /u/apps/example-app/shared/murder/murder_client.py peer '\''/tmp/Test_2.tgz.torrent'\'' '\''/tmp/Test_2.tgz'\'' LC_ALL=C host 172.23.99.7 | awk '\\''/has address/ {print $4}'\\'' | head -n 1'" on 172.23.99.7; "sh -c 'python /u/apps/example-app/shared/murder/murder_client.py peer '\''/tmp/Test_2.tgz.torrent'\'' '\''/tmp/Test_2.tgz'\'' LC_ALL=C host 172.23.98.78 | awk '\\''/has address/ {print $4}'\\'' | head -n 1'" on 172.23.98.78; "sh -c 'python /u/apps/example-app/shared/murder/murder_client.py peer '\''/tmp/Test_2.tgz.torrent'\'' '\''/tmp/Test_2.tgz'\'' LC_ALL=C host 172.23.99.5 | awk '\\''/has address/ {print $4}'\\'' | head -n 1'" on 172.23.99.5
As you can see, it throws an "Incorrect number of arguments" error on every peer.
Everything before that(creating of torrent and initiating of seeding process) worked fine.

Answer 1

I don't think murder is compatible with IP address host definitions. It's expecting a domain name that can be resolved with "host", hence this little beauty from your log output:
`LC_ALL=C host 172.23.99.5 | awk '\\''/has address/ {print $4}'\\'' | head -n 1'`
You'll notice that running that without the backticks--even on an IP address with corresponding DNS entry--yields empty output. That's where the "incorrect number of arguments" error is coming from.
It looks like there's a pull request on github to use ifconfig to figure out the IP address instead of host. You can use that guy's patch, if you want, but it doesn't handle hosts with multiple interfaces. The far and away best solution is to just add some freakin DNS entries for your machines :)
Edit:
Actually, I think this should do the trick for both IP address hosts and DNS server definitions.
Referring again to the pull request, replace the host line with:
HOST = "LC_ALL=C host $CAPISTANO:HOST$ | awk '/has address/ { print $4 } // { print \"$CAPISTRANO:HOST$\" }' | head -n 1"
If the hostname doesn't resolve to an IP address, it just prints out the capistrano host server name, which in your case would be the IP address.