Working with Init Scripts¶
Starting Kapow! using an init script¶
An init program, which can be just a shell script, allows you to make calls to
the kapow route
command.
1 | $ kapow server example-init-program |
With the example-init-program
:
1 2 3 4 5 6 7 8 9 10 | $ cat example-init-program #!/usr/bin/env sh # # This is a simple example of an init program # echo '[*] Starting my init program' # 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 init scripts
Writing Multiline Routes¶
If you need to write more complex actions, you can leverage multiline routes:
1 2 3 4 5 6 | $ cat multiline-route #!/usr/bin/env sh 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 init programs. And you can keep the whole thing documented in one html file, served with Kapow!.
1 2 3 4 5 6 7 8 | $ cat index-route #!/usr/bin/env sh kapow route add / - <<-'EOF' cat howto.html | kapow set /response/body EOF source ./info_stuff source ./other_endpoints |
You can import other shell script libraries with source
.
Debugging Init Programs/Scripts¶
Since Kapow! redirects the standard output and the standard error of the init
program 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 init programs.
$ cat withdebug-route
#!/usr/bin/env sh
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-route