vorteil/direktiv

package target

import (
    "fmt"
    "io"
    "net/http"
    "os"

    "github.com/direktiv/direktiv/pkg/core"
    "github.com/direktiv/direktiv/pkg/gateway"
)

type NamespaceVarPlugin struct {
    Namespace   string `mapstructure:"namespace"`
    Variable    string `mapstructure:"variable"`
    ContentType string `mapstructure:"content_type"`
}

func (tnv *NamespaceVarPlugin) NewInstance(config core.PluginConfig) (core.Plugin, error) {
    pl := &NamespaceVarPlugin{}

    err := gateway.ConvertConfig(config.Config, pl)
    if err != nil {
        return nil, err
    }

    if pl.Variable == "" {
        return nil, fmt.Errorf("variable required")
    }

    return pl, nil
}

func (tnv *NamespaceVarPlugin) Execute(w http.ResponseWriter, r *http.Request) *http.Request {
    currentNS := gateway.ExtractContextEndpoint(r).Namespace
    if tnv.Namespace == "" {
        tnv.Namespace = currentNS
    }
    if tnv.Namespace != currentNS && currentNS != core.SystemNamespace {
        gateway.WriteForbiddenError(r, w, nil, "plugin can not target different namespace")
        return nil
    }

    uri := fmt.Sprintf("http://localhost:%s/api/v2/namespaces/%s/variables?name=%s&raw=true",
        os.Getenv("DIREKTIV_API_PORT"), tnv.Namespace, tnv.Variable)

    resp, err := doRequest(r, http.MethodGet, uri, nil)
    if err != nil {
        gateway.WriteInternalError(r, w, err, "couldn't execute downstream request")
        return nil
    }
    if resp.StatusCode != http.StatusOK {
        gateway.WriteInternalError(r, w, nil, "none ok downstream request: "+resp.Status)
        return nil
    }
    defer resp.Body.Close()

    // copy headers
    for key, values := range resp.Header {
        for _, value := range values {
            w.Header().Add(key, value)
        }
    }
    if tnv.ContentType != "" {
        w.Header().Set("Content-Type", tnv.ContentType)
    }
    // copy the status code
    w.WriteHeader(resp.StatusCode)

    // copy the response body
    if _, err := io.Copy(w, resp.Body); err != nil {
        gateway.WriteInternalError(r, w, nil, "couldn't write downstream response")
        return nil
    }

    return r
}

func (tnv *NamespaceVarPlugin) Type() string {
    return "target-namespace-var"
}

func init() {
    gateway.RegisterPlugin(&NamespaceVarPlugin{})
}