test code

First lets run the below code REMEMBER to change your path:

$url = "https://api.coinmarketcap.com/v1/ticker/?convert=GBP"

Invoke-WebRequest -Uri $url -UseDefaultCredentials -UseBasicParsing | Select-Object -ExpandProperty content > C:\users\adam\desktop\output.json

You can now find the json report file in the directory containing values for all of these coins

Imagine this was an important report that you had processed (we will do a little later), you want to produce it every hour and do something with it. So here we will do the first step of running it every hour.

In your jenkins job, select configure now scroll down until you see BUILD TRIGGERS and click on build periodically . This clock timing is a bit confusing, but you can always google the time conversion you need, for now we will build every hour to do this simply paste in the following.

0 * * * *

Apply and save and now the job will tell you the next time it will run under the box where you just inserted the timecode.

Your Jenkins job will now run every hour.

Ok your report is a good first step, but its not very useful, we need to convert the data to usable objects we can manipulate at will, then we can do stuff like build a report. The first step is to change the code so it doesn't write out the data to file, but saves it as a variable.

$url = "https://api.coinmarketcap.com/v1/ticker/?convert=GBP"

$output = Invoke-WebRequest -Uri $url -UseDefaultCredentials -UseBasicParsing 

Write-Host $output

• You can see this is much more simpler, we just invoke the web request on the URI and save it to a variable $output, then we use Write-Host to display it.

Run this code in Jenkins to be sure it works.

Ok, this is good, but your variable is still a massive string even though it looks like Json, it isn't Json, its just a string. So lets convert it using the powershell special command (other langauges have a similar command).

ADD these three lines

$jsonOutput = ConvertFrom-Json -InputObject $output

Write-Host $jsonOutput.id
Write-Host $jsonOutput.price_gbp

Run your code to make sure it works.

So now we can ouptut the selected id and price, but they are in two piles, lets get them displaying side by side.

for($x=1; $x -le 10; $x++){Write-Host $jsonOutput.id[$x] $jsonOutput.price_gbp[$x]}

Now you should get the jist of how to work with JSON data, powershell and jenkins. This can be really powerful, the next steps would be saving other features of the output such as BTC value to a variable and then producing a HTML report, that can be viewed online. Eventually having your jenkins job upload the report to your website, so you have an up to date price index.

MORE TO COME IN THE FUTURE