Working with pow Files

Starting Kapow! using a pow file

A pow file is just a bash script, where you make calls to the kapow route command.

$ kapow server example.pow

With the example.pow:

$ cat example.pow
#
# This is a simple example of a pow file
#
echo '[*] Starting my script'

# We add 2 Kapow! routes
kapow route add /my/route -c 'echo hello world | kapow set /response/body'
kapow route add -X POST /echo -c 'kapow get /request/body | kapow set /response/body'

Note

Kapow! can be fully configured using just pow files

Load More Than One pow File

You can load more than one pow file at time. This can help you keep your pow files tidy.

$ ls pow-files/
example-1.pow   example-2.pow
$ kapow server <(cat pow-files/*.pow)

Writing Multiline pow Files

If you need to write more complex actions, you can leverage multiline commands:

$ cat multiline.pow
kapow route add /log_and_stuff - <<-'EOF'
     echo this is a quite long sentence and other stuff | tee log.txt | kapow set /response/body
     cat log.txt | kapow set /response/body
EOF

Warning

Be aware of the “-“ at the end of the kapow route add command. It tells kapow route add to read commands from stdin.

Warning

If you want to learn more about multiline usage, see: Here Doc

Keeping Things Tidy

Sometimes things grow, and keeping things tidy is the only way to mantain the whole thing.

You can distribute your endpoints in several pow files. And you can keep the whole thing documented in one html file, served with Kapow!.

$ cat index.pow
kapow route add / - <<-'EOF'
    cat howto.html | kapow set /response/body
EOF

source ./info_stuff.pow
source ./other_endpoints.pow

As you can see, the pow files can be imported into another pow file using source. In fact, a pow file is just a regular shell script.

Debugging scripts

Since Kapow! redirects the standard output and the standard error of the pow file given on server startup to its own, you can leverage set -x to see the commands that are being executed, and use that for debugging.

To support debugging user request executions, the server subcommand has a --debug option flag that prompts Kapow! to redirect both the script’s standard output and standard error to Kapow!’s standard output, so you can leverage set -x the same way as with pow files.

$ cat withdebug.pow
kapow route add / - <<-'EOF'
    set -x
    echo "This will be seen in the log"
    echo "Hi HTTP" | kapow set /response/body
EOF

$ kapow server --debug withdebug.pow