Upgrade to Go 1.21 (#3573)

* Upgrade to Go 1.21

* event: remove tests depending on pointer comparison

The test now just tests that the logger is non-nil. For
some reason the old test was broken by upgrading
to Go 1.21.0.

* api: use dummy Host header for unix sockets

When using unix sockets with the net/http.Client,
we cannot use the unix socket address directly
in the Host header, as it fails the validation step.
Instead, use a dummy address in the Host header.

.go-version

@@ -1 +1 @@
-1.20.5
+1.21.0

api/client.go

@@ -650,8 +650,17 @@ func (c *Client) NewRequest(ctx context.Context, method, requestPath string, bod
 		// be pointing to the protocol used in the application layer and not to
 		// the transport layer. Hence, setting the fields accordingly.
 		u.Scheme = "http"
-		u.Host = socket
 		u.Path = ""
+
+		// Go 1.21.0 introduced strict host header validation for clients.
+		// Using unix domain socket addresses in the Host header fails
+		// this validation. https://go.dev/issue/61431 details this problem.
+		// The error-on-domain-socket-host-header will be removed in a
+		// future release, but in the meantime, we need to set it to something
+		// that isn't the actual unix domain socket address. Following
+		// Docker's lead (https://github.com/moby/moby/pull/45942),
+		// use a localhost TLD.
+		u.Host = "api.boundary.localhost"
 	}
 
 	host := u.Host

internal/observability/event/eventer_test.go

@@ -9,7 +9,6 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
-	"log"
 	"os"
 	"strings"
 	"sync"
@@ -829,7 +828,6 @@ func Test_StandardLogger(t *testing.T) {
 		wantErr         bool
 		wantErrIs       error
 		wantErrContains string
-		wantLogger      *log.Logger
 	}{
 		{
 			name:            "missing-eventer",
@@ -869,11 +867,6 @@ func Test_StandardLogger(t *testing.T) {
 			ctx:       testCtx,
 			eventer:   SysEventer(),
 			eventType: ErrorType,
-			wantLogger: func() *log.Logger {
-				w, err := SysEventer().StandardWriter(testCtx, ErrorType)
-				require.NoError(t, err)
-				return log.New(w, "okay", 0)
-			}(),
 		},
 	}
 	for _, tt := range tests {
@@ -895,7 +888,6 @@ func Test_StandardLogger(t *testing.T) {
 			}
 			require.NoError(err)
 			assert.NotNil(l)
-			assert.Equal(tt.wantLogger, l)
 		})
 	}
 }