Got it working!

Snapshot.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"time"
+)
+
+type SnapshotRecord struct {
+	Id int
+	Timestamp time.Time
+	Temp float32
+	Humidity float32
+	Co2 float32
+}
+
+type SnapshotSubmission struct {
+	Timestamp float32 `json:"time"`
+	Temp float32 `json:"temp"`
+	Humidity float32 `json:"humidity"`
+	Co2 float32 `json:"co2"`
+}
+
+func createSnapshotFromJson(jsonBodyStream io.ReadCloser) (*SnapshotSubmission, error) {
+	var snapshotSub SnapshotSubmission
+	body, err := ioutil.ReadAll(jsonBodyStream)
+	if err != nil {
+		return nil, fmt.Errorf("error reading body stream: %w", err)
+	}
+	err = jsonBodyStream.Close()
+	if err != nil {
+		return nil, fmt.Errorf("couldn't close body stream: %w", err)
+	}
+	err = json.Unmarshal(body, &snapshotSub)
+	if err != nil {
+		return nil, fmt.Errorf("couldn't unmarshal json: %w", err)
+	}
+	return &snapshotSub, nil
+}