I am attempting a 2-part API call to a service for openshift. Results from GET used as payload to POST

Question

I am attempting a 2 part API call to a service for openshift. The first call enables me to GET the template data for the POD we are creating and the second call will call the POST command that leverage the results from the GET within the payload as shown below. The GET returns a large json object. When I get the results from the GET command, I write the results into ioutil.ReadAll() which works fine. I then convert to a string using string() and attempt to use that as the string parameter for "template". The problem that I am facing is that the string parameter contains escape characters. i.e. "{\"kind\":\"Template\",\"apiVersion\":\"template.openshift.io/v1\"...

I can make this work with bash scripts but trying to eliminate the calls to scripts in my code.

BASH SCRIPT EXAMPLE provided by Openshift

$ curl -k \
    -X POST \
    -d @- \
    -H "Authorization: Bearer $TOKEN" \
    -H 'Accept: application/json' \
    -H 'Content-Type: application/json' \
    https://$ENDPOINT/apis/template.openshift.io/v1/namespaces/$NAMESPACE/templateinstances <<EOF
{
  "kind": "TemplateInstance",
  "apiVersion": "template.openshift.io/v1",
  "metadata": {
    "name": "templateinstance"
  },
  "spec": {
    "secret": {
      "name": "secret"
    },
    "template": $(curl -k \
                    -H "Authorization: Bearer $TOKEN" \
                    -H 'Accept: application/json' \
                    https://$ENDPOINT/apis/template.openshift.io/v1/namespaces/openshift/templates/cakephp-mysql-example)
  }
}
EOF

Example Go code...

func main() {
    b, res := getTemplateData()
    if !b{
        fmt.Println(res)
        os.Exit(1)
    }else{
        createTemplate(res)
    }
}

type templateInstance struct{
    Kind string `json:"kind"`
    ApiVersion string `json:"apiVersion"`
    Metadata MetaData `json:"metadata"`
    Spec spec `json:"spec"`
}

type spec struct {
    Secret Tsecret `json:"secret"`
    Template string `json:"template"`
}
type Tsecret struct{
    Name string `json:"name"`
}

func createTemplate(t string) {
    var md MetaData
    var sp spec
    var ts Tsecret

    md.Name = "template_name"
    ts.Name = "secret_name"


    sp.Secret = ts
    sp.Template = t

    var ti = templateInstance {
        Kind: "TemplateInstance",
        ApiVersion: "template.openshift.io/v1",
        Metadata: md,
        Spec: sp,
    }

    templateData, _ := json.Marshal(ti)
    fmt.Println(string(templateData))

}


func getTemplateData() (bool, string){

    URL := "https://example.com/apis/template.openshift.io/v1/namespaces/mynamespace/templates/mytemplate"
    client := &http.Client{
        Timeout:5*time.Second,
        Transport: &http.Transport{
            Proxy:nil,
            TLSClientConfig: &tls.Config{InsecureSkipVerify:true},
        },
    }

    req, err := http.NewRequest("GET", URL, nil)
    if err != nil{
        fmt.Println(err)
        os.Exit(0)
    }

    req.Header.Add("Accept", "application/json")
    req.Header.Add("Authorization", myToken)
    req.Header.Add("cache-control", "no-cache")

    res, err := client.Do(req)
    if err != nil{
        fmt.Println("client.Do error")
        fmt.Println(err)
        return false, "Error calling get template"

    }
    defer res.Body.Close()
    body, err := ioutil.ReadAll(res.Body)
    if err != nil{
        return false, "Error reading Template result"
    }else{
        return true, string(body)
        //string(body) gets used as the string value for "template" parameter of the payload in the bash script example...
    }

}

The problem is in the code we cannot see. Edit the question to show the code that calls getTemplateData() and makes the second request. — Cerise Limón
Hi @MuffinTop, I edited the post to hopefully give you rest of the code that shows how I am trying to solve and where the problem might lie. Thanks — PaddySean

Cerise Limón Cerise Limón · Accepted Answer · 2020-06-07T18:33:56

The extra escapes are the result encoding a JSON document as JSON.

Use json.RawMessage to pass the JSON template through to the output as is.

type spec struct {
    Secret   Tsecret         `json:"secret"`
    Template json.RawMessage `json:"template"`
}

...

sp.Template = json.RawMessage(t)

I am attempting a 2-part API call to a service for openshift. Results from GET used as payload to POST

1 Answers