logpolicy: fix log target override with a custom HTTP client

This makes sure that the log target override is respected even if a
custom HTTP client is passed to logpolicy.

Updates tailscale/maple#29

Signed-off-by: Anton Tolchanov <anton@tailscale.com>

logpolicy/logpolicy_test.go

@@ -4,6 +4,7 @@
 package logpolicy
 
 import (
+	"net/http"
 	"os"
 	"reflect"
 	"testing"
@@ -11,12 +12,14 @@ import (
 	"tailscale.com/logtail"
 )
 
-func TestLogHost(t *testing.T) {
+func resetLogTarget() {
+	os.Unsetenv("TS_LOG_TARGET")
 	v := reflect.ValueOf(&getLogTargetOnce).Elem()
-	reset := func() {
-		v.Set(reflect.Zero(v.Type()))
-	}
-	defer reset()
+	v.Set(reflect.Zero(v.Type()))
+}
+
+func TestLogHost(t *testing.T) {
+	defer resetLogTarget()
 
 	tests := []struct {
 		env  string
@@ -29,10 +32,55 @@ func TestLogHost(t *testing.T) {
 		{"https://foo.com:123/", "foo.com"},
 	}
 	for _, tt := range tests {
-		reset()
+		resetLogTarget()
 		os.Setenv("TS_LOG_TARGET", tt.env)
 		if got := LogHost(); got != tt.want {
 			t.Errorf("for env %q, got %q, want %q", tt.env, got, tt.want)
 		}
 	}
 }
+func TestOptions(t *testing.T) {
+	defer resetLogTarget()
+
+	tests := []struct {
+		name        string
+		opts        func() Options
+		wantBaseURL string
+	}{
+		{
+			name:        "default",
+			opts:        func() Options { return Options{} },
+			wantBaseURL: "",
+		},
+		{
+			name: "custom_baseurl",
+			opts: func() Options {
+				os.Setenv("TS_LOG_TARGET", "http://localhost:1234")
+				return Options{}
+			},
+			wantBaseURL: "http://localhost:1234",
+		},
+		{
+			name: "custom_httpc_and_baseurl",
+			opts: func() Options {
+				os.Setenv("TS_LOG_TARGET", "http://localhost:12345")
+				return Options{HTTPC: &http.Client{Transport: noopPretendSuccessTransport{}}}
+			},
+			wantBaseURL: "http://localhost:12345",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			resetLogTarget()
+			config, policy := tt.opts().init(false)
+			if policy == nil {
+				t.Fatal("unexpected nil policy")
+			}
+			if config.BaseURL != tt.wantBaseURL {
+				t.Errorf("got %q, want %q", config.BaseURL, tt.wantBaseURL)
+			}
+			policy.Close()
+		})
+	}
+}