# Installing Kapow! Kapow! has a reference implementation in Go that is under active develpment right now. If you want to start using kapow you can: * Download a binary (linux, at this moment) from our [releases](https://github.com/BBVA/kapow/releases) section * Install the package with the get command (you need the Go runtime installed and [configured](https://golang.org/cmd/go/)) ```Shell go get -u github.com/BBVA/kapow ``` # Examples Below are some examples on how to define and invoke routes in Kapow! As you can see Kapow! binary is a server and a CLI that you can use to configure a running server. The server exposes an [API](/spec#http-control-api) that you can invoke directly if you want. In order to get information from the request that fired the scrip execution and to help you in composing the response, the server exposes some [resources](/spec#handlers) to interact with from the script. ## The mandatory Hello World (for WWW fans) First you create a pow file named `greet.pow` with the following contents: ```Shell kapow route add /greet -c 'name=$(kapow get /request/params/name); echo Hello ${name:-World} | kapow set /response/body' ``` note you have to escape as the command will run on a shell itself. Then, you execute: ```Shell kapow server greet.pow ``` to start a Kapow! server exposing your service. Now you can check that it works as intended with good ole' ``curl``: ```Shell curl localhost:8080/greet Hello World curl localhost:8080/greet?name=friend Hello friend ``` If you want to work with JSON you can use this version of the pow `greet-json.pow` ```Shell kapow route add -X POST /greet -c 'kapow route add -X POST /greet -c 'who=$(kapow get /request/body | jq -r .name); kapow set /response/status 201; jq --arg value "${who:-World}" -n \{name:\$value\} | kapow set /response/body'' ``` that uses [jq](https://stedolan.github.io/jq/) to allow you working with json from the command line. Check that it works with ```Shell curl -X POST -H "Content-Type: application/json" -d '{"name": "friend"}' localhost:8080/greet {"name": "friend" } curl -X POST -H "Content-Type: application/json" -d '' localhost:8080/greet {"name": "World"} ``` ## The mandatory Echo (for UNIX fans) First you create a pow file named `echo.pow` with the following contents: ```Shell kapow route add -X POST /echo -c 'kapow get /request/body | kapow set /response/body' ``` then, you execute: ```Shell kapow server echo.pow ``` and you can check that it works as intended with good ole' `curl`: ```Shell curl -X POST -d '1,2,3... testing' localhost:8080/echo 1, 2, 3, 4, 5, 6, 7, 8, 9, testing ``` If you send a big file and want to see the content back as a real-time stream you can use this version `echo-stream.pow` ```Shell kapow route add -X POST /echo -c 'kapow get /request/body | kapow set /response/stream' ``` ## The multiline fun Unless you're a hardcore Perl hacker, you'll probably need to write your stuff over more than one line in order to avoid the mess we saw on our json greet version. Don't worry, we need to write several lines, too. Bash, in its magnificent UNIX® style, provides us with the [here-documents](https://www.gnu.org/software/bash/manual/bash.html#Here-Documents) mechanism that we can leverage precisely for this purpose. Imagine we want to return both the standard output and a generated file from a command execution. Let's write a `log-and-stuff.pow` file with the following content: ```Shell 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 ``` then we serve it with `kapow`: ```Shell kapow server log-and-stuff.pow ``` Yup. As simple as that. You can check it. ```Shell curl localhost:8080/log_and_stuff this is a quite long sentence and other stuff this is a quite long sentence and other stuff ``` ## Interact with other systems You can leverage all the power of the shell in your scripts and interact with other systems by using all the available tools. Write a `log-and-stuff-callback.pow` file with the following content: ```Shell kapow route add /log_and_stuff - <<- 'EOF' callback_url=$(kapow get /request/params/callback) echo this is a quite long sentence and other stuff | tee log.txt | kapow set /response/body echo sending to $callback_url | kapow set /response/body curl -X POST --data-binary @log.txt $callback_url | kapow set /response/body EOF ``` serve it with `kapow`: ```Shell kapow server log-and-stuff-callback.pow ``` and finally check it. ```Shell curl localhost:8080/log_and_stuff?callback=nowhere.com this is a quite long sentence and other stuff sending to nowhere.com 405 Not Allowed

405 Not Allowed

nginx
``` You must be aware that you must have all the dependencies you use in your scripts installed in the host that will run the Kapow! server. In addition, a pow file can contain as much routes as you like so you can start a server with several routes configured in one shoot. # Sample Docker usage ## Clone the project ```Shell git clone https://github.com/BBVA/kapow.git ``` ## Build the kapow! docker image ```Shell make docker ``` Now you have a container image with all the above pow files copied in /tmp so you can start each example by running ```Shell docker run --rm -p 8080:8080 docker server example.pow ``` ## Build a docker image for running the nmap example ```Shell cd /path/to/kapow/poc/examples/nmap; docker build -t kapow-nmap . ``` ## Run kapow ```Shell docker run \ -d \ -p 8080:8080 \ kapow-nmap ``` which will output something like this: ```Shell e7da20c7d9a39624b5c56157176764671e5d2d8f1bf306b3ede898d66fe3f4bf ``` ## Test /list endpoint In another terminal, try running: ```Shell curl http://localhost:8080/list/github.com ``` which will respond something like: ```Shell Starting Nmap 7.70 ( https://nmap.org ) at 2019-05-10 14:01 UTC Nmap scan report for github.com (140.82.118.3) rDNS record for 140.82.118.3: lb-140-82-118-3-ams.github.com Nmap done: 1 IP address (0 hosts up) scanned in 0.04 seconds ``` et voilà ! # License This project is distributed under the [Apache License 2.0](/LICENSE).