Session management

[hyperbart]

To be able to request a JSON a valid session has to be present.

Handling valid sessions is now done by logging on to the LAP and copying this SID to the respective monitoring app.

This should be automated

[brvdboss]

Hello,

login can be done as follows:

curl -X POST -d '{"right": "usr", "pass": "YOURPASSWORD"}' "http://SMA-IP/dyn/login.json"

The inverter seems picky about the spaces in the json input. So make sure there is a space after each colon.
As a result you'll receive a json file out of which the session value can be extracted using jq

jq -r .result.sid

Logging out is similar:

curl -X POST --data-binary {} http://SMA-IP/dyn/logout.json?sid=SESSION

It's needed to explicitely to have the empty json as input or it wil fail.

If you whish to combine it all in one commandline request you could do it as follows (by putting the session-id in an environment variable:

SESSION=`curl -s -X POST -d '{"right": "usr", "pass": "YOURPASSWORD"}' "http://SMA-IP/dyn/login.json" | jq -r .result.sid` && curl.exe -s --data-binary {\"destDev\":[]} http://SMA-IP/dyn/getAllOnlValues.json?sid=$SESSION && curl -s -X POST --data-binary {} http://SMA-IP/dyn/logout.json?sid=$SESSION >>/dev/null
Running curl in silent mode -s and redirecting the output of the logout command to /dev/null as we don't use that response data (which is of the form {"result":{"isLogin":false}}
If you don't want the password to be visible in the commandline/shell (for example when someone does a ps and sees it in plaintext you can put them in a file and reference that file
-d "@data.json
where the file data.json contains the content {"right": "usr", "pass": "YOURPASSWORD"}

Obviously, replace YOURPASWORD with your password and SMA-IP with the IP or hostname of your inverter

Using this approach you'll login & out on every call. Logging out is important as well as the inverter allows only a small number of simultaneous logins (approximately 3 or 4 it seems)

Getting a new session every time probably isn't needed either, but doing it minimizes the need to validate if the session is still alive.