HttpClient post to influxdb problem

Troubleshooting
1

Hi I am trying to use the HttpClient lib to post data to my influxdb.
But I alwas get this error message:

Response status: -1
HTTP Response Body:

Here is my Code. I would be really happy if someone can point me to my problem here:

    #include "HttpClient.h"
    
    /**
    * Declaring the variables.
    */
    unsigned int nextTime = 0;    // Next time to contact the server
    HttpClient http;
    
    // Headers currently need to be set at init, useful for API keys etc.
    http_header_t headers[] = {
        //  { "Content-Type", "application/json" },
        //  { "Accept" , "application/json" },
        { "Accept" , "*/*"},
        { NULL, NULL } // NOTE: Always terminate headers will NULL
    };
    
    http_request_t request;
    http_response_t response;
    
    void setup() {
        Serial.begin(9600);
    }
    
    void loop() {
        if (nextTime > millis()) {
            return;
        }
    
        Serial.println();
        Serial.println("Application>\tStart of Loop.");
        // Request path and body can be set at runtime or at setup.
        request.hostname = "http://myurl.dlinkddns.com";
        request.port = 8086;
        request.path = "/query";
    
        // The library also supports sending a body with your request:
        request.body = "{\"q\"=\"CREATE DATABASE mytestdb\"}";
    
        // Post request
        http.post(request, response, headers);
        Serial.print("Application>\tResponse status: ");
        Serial.println(response.status);
    
        Serial.print("Application>\tHTTP Response Body: ");
        Serial.println(response.body);
    
        nextTime = millis() + 10000;
    }
2

First drop the http:// in the host name.
The protocol denomination is not part of the host name.

Then try again.

2 Likes
3

Tank you, this was a good step forward!
Now I fight with the problem that I get this error message back:

Response status:400
HTTP Response Body: {"error":"missing required parameter "q""}

    #include "HttpClient.h"
    
    /**
    * Declaring the variables.
    */
    unsigned int nextTime = 0;    // Next time to contact the server
    HttpClient http;
    
    // Headers currently need to be set at init, useful for API keys etc.
    http_header_t headers[] = {
        //{ "Content-Type", "application/json" },
        //  { "Accept" , "application/json" },
        { "Accept" , "*/*"},
        { "User-agent", "Particle HttpClient"},
        { NULL, NULL } // NOTE: Always terminate headers will NULL
    };
    
        http_request_t request;
        http_response_t response;
        
        void setup() {
            Serial.begin(9600);
        }
        
        void loop() {
            if (nextTime > millis()) {
                return;
            }
        
            Serial.println();
            Serial.println("Application>\tStart of Loop.");
            // Request path and body can be set at runtime or at setup.
            request.hostname = "mysite.dlinkddns.com";
            request.port = 8086;
            request.path = "/query";
        
            // The library also supports sending a body with your request:
           request.body = "{\"q\":\"CREATE DATABASE mytestdb2\"}";
            //request.body = "q=CREATE DATABASE masdasd";
        
            // Get request
            http.get(request, response, headers);
            Serial.print("Application>\tResponse status: ");
            Serial.println(response.status);
        
            Serial.print("Application>\tHTTP Response Body: ");
            Serial.println(response.body);
        
            nextTime = millis() + 10000;
        }

THis curl command worked in/outside my network:

curl -G mysite.dlinkddns.com:8086/query --data-urlencode "q=CREATE DATABASE mydb1234"

4

Is this comment

suggesting that you had tried this and it didn't work either?
If not, try it.

5

The code above uses http.get() but get() doesn’t use the request.body; only post() uses request.body.

Since your curl command used get (-G), I think what you want is

request.path = “/query?q%3DCREATE%20DATABASE%20mydb1234";

That’s the URL encoded (—data-urlencode) version appended to the GET query string.

3 Likes
6

Thank you for this idea but I still get the same error with it:

request.path = "/query?q%3DCREATE%20DATABASE%20mydb1234";

still gives me

Response status:400
HTTP Response Body: {"error":"missing required parameter "q""}

Just a side note if I enter this into a browser outside my network it works:

mysite.dlinkddns.com:8086/query?q=CREATE DATABASE mydb1234

so I tryed to do the following:

request.path = "/query?q=CREATE DATABASE mydb1234";

But this gives me my first error again:

Response status: -1
HTTP Response Body:

7

aww solved it with the following line:

request.path = "/query?q=CREATE+DATABASE+mydb1234";

Thank you @rickkas7 and @ScruffR for your help

2 Likes
8

I am trying to insert data now with the following:

http_header_t headers[] = {
    //{ "Content-Type", "application/json" },
    //  { "Accept" , "application/json" },
    { "Accept" , "*/*"},
    { "User-agent", "Particle HttpClient"},
    { NULL, NULL } // NOTE: Always terminate headers will NULL
};

...

 request.path = "/write?db=mydb1234";
 request.body = "\"cpu_load_short,host=server01,region=us-west value=0.64\"";
 http.post(request, response, headers);

But this gets me this error:

HTTP Response Body: {"error":"unable to parse
'"cpu_loadshort...value=0.64"':invalid number"}

Maybe someone has an idea what I have to change to get a post working

9

Try changing:

request.body = "“cpu_load_short,host=server01,region=us-west value=0.64"”;

to

request.body = “cpu_load_short,host=server01,region=us-west value=0.64”;

because I don’t think you need the embedded double-quotes for the data. I’ve just tried something similar from curl to my Influx database.

10

oh god that was it, thank you I was sure I allready tryed it without the quotes

11

It sounds like you are at the same stage of using Influxdb as I was a few weeks ago :smile:

I recommend reading https://docs.influxdata.com/influxdb/v0.10/write_protocols/line/ to understand how to set the datatypes of the fields, especially for integers, and escaping spaces etc. You’ll need double-quotes in some places but not in others. It’s not intuitive.

12

yea thank you I will check it out :wink:
For today I need a break, what I planedto be a 30min tasked developed to a whole day problem :smiley: