feat: Allow forcing either IPV4 or IPV6 network connections only

Dockerfile

@@ -29,6 +29,8 @@ ENTRYPOINT ["/ovai"]
 ARG DEBUG=ovai,ovai:srv
 ENV DEBUG=${DEBUG}
 ENV PORT=22434
+ENV NETWORK=
+ENV OLLAMA_ORIGIN=
 
 # HEALTHCHECK --interval=5m \
 # CMD /healthchk http://localhost:22434/api/ping || exit 1

README.md

@@ -58,6 +58,13 @@ Set the environment variable `DEBUG` to one or more strings separated by commas
 
 Set the environment variable `OLLAMA_ORIGIN` to the origin of the `ollama` service to enable forwarding to `ollama`. If the requested model doesn't start with `gemini`, `chat-bison`, `text-bison` or `textembedding-gecko`, the request will be forwarded to the `ollama` service. This can be used for using `ovai` as the single service with the `ollama` interface, which recognises both `Vertex AI` and `ollama` models.
 
+Set the environment variable `NETWORK` to enforce IPV4 or IPV6. The default behaviour is to depend on tHe [Happy Eyeballs] implementation in Go and in the underlying OS. valid values:
+
+| `NETWORK` value | What will be used |
+|:----------------|:---------------------------------------------|
+| `IPV4` | enforce the network connection via IPV4 only |
+| `IPV6` | enforce the network connection via IPV6 only |
+
 ### Docker
 
 For example, run a container for testing purposes with verbose logging, deleted on exit, exposing the port 22434:
@@ -226,6 +233,7 @@ Licensed under the [MIT License].
 [GitHub Releases]: https://github.com/prantlf/ovai/releases/
 [Go]: https://go.dev
 [default model parameters]: ./model-defaults.json
+[Happy Eyeballs] :https://en.wikipedia.org/wiki/Happy_Eyeballs
 [docker-compose.yml]: ./docker-compose.yml
 [REST API documentation]: https://github.com/ollama/ollama/blob/main/docs/api.md
 [embedding models]: https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/text-embeddings#model_versions

internal/web/request.go

@@ -2,10 +2,13 @@ package web
 
 import (
  "bytes"
+ "context"
  "encoding/json"
  "errors"
  "io"
+ "net"
  "net/http"
+ "os"
 
  "github.com/prantlf/ovai/internal/log"
 )
@@ -121,8 +124,64 @@ func CreateRawPostRequest(url string, input []byte) (*http.Request, error) {
  return req, nil
 }
 
-func DispatchRequest(req *http.Request, output interface{}) (int, error) {
+// type happyEyeballs int
+
+// const (
+// ipDefault happyEyeballs = iota + 1
+// ipV4
+// ipV6
+// )
+
+// var happyEyeballNames = [...]string{"Default", "IPV4", "IPV6"}
+
+// func (h happyEyeballs) String() string {
+// return happyEyeballNames[h-1]
+// }
+
+// func (h happyEyeballs) EnumIndex() int {
+// return int(h)
+// }
+
+// func parseHappyEyeballs(input string) (happyEyeballs, error) {
+// for index, value := range happyEyeballNames {
+// if value == input {
+// return happyEyeballs(index), nil
+// }
+// }
+// return 0, fmt.Errorf("invalid enum value: %q", input)
+// }
+
+var dialer net.Dialer
+var networkVersion = initDialer()
+
+func initDialer() string {
+ network := os.Getenv("NETWORK")
+ if len(network) > 0 {
+ if network == "IPV4" {
+ return "tcp4"
+ }
+ if network == "IPV6" {
+ return "tcp6"
+ }
+ log.Ftl("Invalid value of NETWORK variable: %q", network)
+ }
+ return ""
+}
+
+func createHttpClient() *http.Client {
  client := &http.Client{}
+ if len(networkVersion) > 0 {
+ transport := http.DefaultTransport.(*http.Transport).Clone()
+ transport.DialContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
+ return dialer.DialContext(ctx, networkVersion, addr)
+ }
+ client.Transport = transport
+ }
+ return client
+}
+
+func DispatchRequest(req *http.Request, output interface{}) (int, error) {
+ client := createHttpClient()
  res, err := client.Do(req)
  if err != nil {
  log.Dbg("making request failed: %v", err)
@@ -170,7 +229,7 @@ func DispatchRequest(req *http.Request, output interface{}) (int, error) {
 }
 
 func DispatchRawRequest(req *http.Request) (int, []byte, error) {
- client := &http.Client{}
+ client := createHttpClient()
  res, err := client.Do(req)
  if err != nil {
  log.Dbg("making request failed: %v", err)