How to restart flows automatically?

General
1

Dear all,

We're encountering a situation whereby if we have loss of connectivity, a number of flows (namely websocket nodes) fail to reconnect, while I realise we could check the source for the problematic nodes and implement a reconnect mechanism, this isn't viable for number of nodes we use (longterm, yes).

Is there a way to restart flows from within Node Red? This would not only be useful to overcome the above, but also for testing purposes... Failing that we're considering triggering a script for the container from within Node Red itself?

Any advice would be greatly appreciated.

2

You can use the admin http API to get the runtime to reload it's flows. An http post to /flows with the right headers set should do it.

https://nodered.org/docs/api/admin/methods/post/flows/

3

@swiftnesses did you manage to implement that? I'm trying to do the same thing.

4

Sadly I didn't get the reloading of flows working from within Node Red (I got bad request 400), perhaps @knolleary has a simple example we can utilise? Currently I use an external script, but it's far from ideal.

5

Here's an example of what I tried... Sadly, I don't have a clar understanding of the API :blush:

[{"id":"318bc319.545c8c","type":"inject","z":"85ff7c27.d1f9e","name":"","topic":"","payload":"{}","payloadType":"json","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":150,"y":340,"wires":[["6127a9be.73ed48"]]},{"id":"8e46bf1d.9cec7","type":"http request","z":"85ff7c27.d1f9e","name":"POST /auth/token","method":"POST","ret":"txt","url":"http://localhost:1880/auth/token","tls":"","x":570,"y":340,"wires":[["8d950fde.e890c"]]},{"id":"6127a9be.73ed48","type":"change","z":"85ff7c27.d1f9e","name":"","rules":[{"t":"set","p":"payload.client_id","pt":"msg","to":"node-red-editor","tot":"str"},{"t":"set","p":"payload.grant_type","pt":"msg","to":"password","tot":"str"},{"t":"set","p":"payload.scope","pt":"msg","to":"*","tot":"str"},{"t":"set","p":"payload.username","pt":"msg","to":"CHANGE_ME","tot":"str"},{"t":"set","p":"payload.password","pt":"msg","to":"CHANGE_ME","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":340,"y":340,"wires":[["8e46bf1d.9cec7"]]},{"id":"38985da.ce401a2","type":"change","z":"85ff7c27.d1f9e","name":"","rules":[{"t":"set","p":"token","pt":"flow","to":"payload","tot":"msg"}],"action":"","property":"","from":"","to":"","reg":false,"x":1120,"y":340,"wires":[["88e94d53.649b"]]},{"id":"8d950fde.e890c","type":"json","z":"85ff7c27.d1f9e","name":"","property":"payload","action":"","pretty":false,"x":770,"y":340,"wires":[["af3a2700.a4dc38"]]},{"id":"88e94d53.649b","type":"change","z":"85ff7c27.d1f9e","name":"","rules":[{"t":"delete","p":"headers","pt":"msg"},{"t":"set","p":"headers.Authorization","pt":"msg","to":"token.access_token","tot":"flow"},{"t":"set","p":"headers.Node-RED-Deployment-Type","pt":"msg","to":"reload","tot":"str"},{"t":"set","p":"headers.Node-RED-API-Version","pt":"msg","to":"v1","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":1340,"y":340,"wires":[["134799e1.f6e326"]]},{"id":"af3a2700.a4dc38","type":"function","z":"85ff7c27.d1f9e","name":"Bearer","func":"msg.payload.access_token = \"Bearer \" + msg.payload.access_token\nreturn msg;","outputs":1,"noerr":0,"x":930,"y":340,"wires":[["38985da.ce401a2"]]},{"id":"134799e1.f6e326","type":"http request","z":"85ff7c27.d1f9e","name":"POST /flows","method":"POST","ret":"txt","paytoqs":false,"url":"http://localhost:1880/flows","tls":"","persist":false,"proxy":"","authType":"","x":1550,"y":340,"wires":[["3d8d2c74.71d704"]]},{"id":"3d8d2c74.71d704","type":"debug","z":"85ff7c27.d1f9e","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","x":1730,"y":340,"wires":[]}]

1 Like
6

@swiftnesses

I had the same issue, and resolved it with the below code

[{"id":"e3f0c29b.15917","type":"function","z":"45ec8d76.35a444","name":"Request Token","func":"msg.payload = {\n    \"client_id\": \"node-red-editor\",\n    \"grant_type\": \"password\",\n    \"scope\": \"*\",\n    \"username\": \"type or username\",\n    \"password\": \"type your password\"\n}\nreturn msg;","outputs":1,"noerr":0,"x":440,"y":760,"wires":[["40715257.e3114c"]]},{"id":"62e6b42a.d2df5c","type":"inject","z":"45ec8d76.35a444","name":"Manual reload","topic":"","payload":"","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":"","x":230,"y":760,"wires":[["e3f0c29b.15917"]]},{"id":"40715257.e3114c","type":"http request","z":"45ec8d76.35a444","name":"Token","method":"POST","ret":"txt","paytoqs":false,"url":"http://localhost:1880/auth/token","tls":"","persist":false,"proxy":"","authType":"","x":630,"y":760,"wires":[["27f2916.2d1306e"]]},{"id":"27f2916.2d1306e","type":"function","z":"45ec8d76.35a444","name":"Confirm token","func":"// get the status of the request\nvar status = msg.statusCode;\n//var token = {};\nvar token = '';\nmsg.headers ={};\n\n//let node = feedback;\n\nswitch(status){\n    case 200:\n        node.log(\"Secure restart\");\n        token = JSON.parse(msg.payload);\n        token = 'Bearer '+token.access_token;\n        msg.headers = {\n            \"Authorization\": token,\n            \"Node-RED-Deployment-Type\":\"reload\"\n        }\nmsg.payload =\"\";\n        break;\n    case 204:\n        node.log(\"Secure without restart\");\n        global.set('result','\tSuccess - with no further content');\n        break;\n    case 400:\n        node.warn(\"Bad request\");\n        break;\n    case 401:\n        node.warn(\"Not authorized\");\n        break;\n    case 403:\n        node.warn(\"Forbidden\");\n        break;\n    case 404:\n        node.log(\"Unsecure restart\");\n        msg.headers = {\n            \"Node-RED-Deployment-Type\":\"reload\"\n        }\n        break;\n    case 409:\n        node.warn(\"Version mismatch\");\n        break;\n    case 500:\n        node.error(\"Server Error\");\n        break;\n    default:\n        node.warn(\"Unknown Error\");\n       break;\n}\n\nmsg.payload = \"\";\nreturn msg;","outputs":1,"noerr":0,"x":820,"y":760,"wires":[["cbf97372.7169f"]],"info":"Restart of Node-Red flows.\nWill check if the action needs security or not.\nNote: if the first 5 attemps return a statuscode 403 'forbidden'\nthen the server will break and only way to recover is then to\nrestart the service"},{"id":"cbf97372.7169f","type":"http request","z":"45ec8d76.35a444","name":"Restart","method":"POST","ret":"txt","paytoqs":false,"url":"http://localhost:1880/flows","tls":"","persist":false,"proxy":"","authType":"","x":1020,"y":760,"wires":[[]]}]

There is still a minor issue with it.
If the function returns within the first 5 attempts a statuscode 403 'forbidden' then the 6th attempt will break the server (code 500 and only way to recover is then to restart the service)

:slight_smile:

1 Like
7

@AsHex_66
Hi,
your code is working fine, thanks! But I need to restart only the flow on which the code is deployed, instead of all of them. Is it possible?