Codespaces: Use the host name from the logged in server for commands (c…

…li#7795)

* Use the host name from the logged in server for codespace commands

* Fix existing tests

* Add tests for server url configuration

* Rename defaultApiUrl to defaultAPIURL and comment cleanup

* Switch to t.Setenv in codespaces api tests

* Switch to t.Setenv in other tests

* Support custom server in web flows for list and create

* Rename GetServerURL() to ServerURL()

internal/codespaces/api/api.go

@@ -1,13 +1,12 @@
 package api
 
 // For descriptions of service interfaces, see:
-// - https://online.visualstudio.com/api/swagger (for visualstudio.com)
 // - https://docs.github.com/en/rest/reference/repos (for api.github.com)
 // - https://github.com/github/github/blob/master/app/api/codespaces.rb (for vscs_internal)
 // TODO(adonovan): replace the last link with a public doc URL when available.
 
 // TODO(adonovan): a possible reorganization would be to split this
-// file into three internal packages, one per backend service, and to
+// file into two internal packages, one per backend service, and to
 // rename api.API to github.Client:
 //
 // - github.GetUser(github.Client)
@@ -20,7 +19,6 @@ package api
 // - codespaces.GetToken(Client, login, name)
 // - codespaces.List(Client, user)
 // - codespaces.Start(Client, token, codespace)
-// - visualstudio.GetRegionLocation(http.Client) // no dependency on github
 //
 // This would make the meaning of each operation clearer.
 
@@ -34,6 +32,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"os"
 	"reflect"
 	"regexp"
 	"strconv"
@@ -42,13 +41,14 @@ import (
 
 	"github.com/cenkalti/backoff/v4"
 	"github.com/cli/cli/v2/api"
+	"github.com/cli/cli/v2/internal/ghinstance"
+	"github.com/cli/cli/v2/pkg/cmdutil"
 	"github.com/opentracing/opentracing-go"
 )
 
 const (
-	githubServer = "https://github.com"
-	githubAPI    = "https://api.github.com"
-	vscsAPI      = "https://online.visualstudio.com"
+	defaultAPIURL    = "https://api.github.com"
+	defaultServerURL = "https://github.com"
 )
 
 const (
@@ -60,31 +60,40 @@ const (
 
 // API is the interface to the codespace service.
 type API struct {
-	client       httpClient
-	vscsAPI      string
+	client       func() (*http.Client, error)
 	githubAPI    string
 	githubServer string
 	retryBackoff time.Duration
 }
 
-type httpClient interface {
-	Do(req *http.Request) (*http.Response, error)
-}
-
 // New creates a new API client connecting to the configured endpoints with the HTTP client.
-func New(serverURL, apiURL, vscsURL string, httpClient httpClient) *API {
-	if serverURL == "" {
-		serverURL = githubServer
-	}
+func New(f *cmdutil.Factory) *API {
+	apiURL := os.Getenv("GITHUB_API_URL")
 	if apiURL == "" {
-		apiURL = githubAPI
+		cfg, err := f.Config()
+		if err != nil {
+			// fallback to the default api endpoint
+			apiURL = defaultAPIURL
+		} else {
+			host, _ := cfg.Authentication().DefaultHost()
+			apiURL = ghinstance.RESTPrefix(host)
+		}
 	}
-	if vscsURL == "" {
-		vscsURL = vscsAPI
+
+	serverURL := os.Getenv("GITHUB_SERVER_URL")
+	if serverURL == "" {
+		cfg, err := f.Config()
+		if err != nil {
+			// fallback to the default server endpoint
+			serverURL = defaultServerURL
+		} else {
+			host, _ := cfg.Authentication().DefaultHost()
+			serverURL = ghinstance.HostPrefix(host)
+		}
 	}
+
 	return &API{
-		client:       httpClient,
-		vscsAPI:      strings.TrimSuffix(vscsURL, "/"),
+		client:       f.HttpClient,
 		githubAPI:    strings.TrimSuffix(apiURL, "/"),
 		githubServer: strings.TrimSuffix(serverURL, "/"),
 		retryBackoff: 100 * time.Millisecond,
@@ -97,6 +106,11 @@ type User struct {
 	Type  string `json:"type"`
 }
 
+// ServerURL returns the server url (not the API url), such as https://github.com
+func (a *API) ServerURL() string {
+	return a.githubServer
+}
+
 // GetUser returns the user associated with the given token.
 func (a *API) GetUser(ctx context.Context) (*User, error) {
 	req, err := http.NewRequest(http.MethodGet, a.githubAPI+"/user", nil)
@@ -1119,7 +1133,13 @@ func (a *API) do(ctx context.Context, req *http.Request, spanName string) (*http
 	span, ctx := opentracing.StartSpanFromContext(ctx, spanName)
 	defer span.Finish()
 	req = req.WithContext(ctx)
-	return a.client.Do(req)
+
+	httpClient, err := a.client()
+	if err != nil {
+		return nil, err
+	}
+
+	return httpClient.Do(req)
 }
 
 // setHeaders sets the required headers for the API.