From 399b1ec2d598b7950816727b8d92e8580553372c Mon Sep 17 00:00:00 2001 From: Sanskar Jaiswal Date: Tue, 18 Apr 2023 16:31:58 +0530 Subject: plumbing: transport/http, refactor transport to cache underlying transport objects Refactor the in-built http transport to cache the underlying http transport objects mapped to its specific options for each Git transport object. This lets us reuse the transport for a specific set of configurations as recommended. (ref: https://pkg.go.dev/net/http#Transport) If there are no transport specific options provided, the default transport is used. Signed-off-by: Sanskar Jaiswal --- plumbing/transport/http/common.go | 147 +++++++++++++++++++++++++++++++++++--- 1 file changed, 136 insertions(+), 11 deletions(-) (limited to 'plumbing/transport/http/common.go') diff --git a/plumbing/transport/http/common.go b/plumbing/transport/http/common.go index d57c0fe..5300341 100644 --- a/plumbing/transport/http/common.go +++ b/plumbing/transport/http/common.go @@ -4,16 +4,21 @@ package http import ( "bytes" "context" + "crypto/tls" + "crypto/x509" "fmt" "net" "net/http" + "reflect" "strconv" "strings" + "sync" "github.com/go-git/go-git/v5/plumbing" "github.com/go-git/go-git/v5/plumbing/protocol/packp" "github.com/go-git/go-git/v5/plumbing/transport" "github.com/go-git/go-git/v5/utils/ioutil" + "github.com/golang/groupcache/lru" ) // it requires a bytes.Buffer, because we need to know the length @@ -74,40 +79,83 @@ func advertisedReferences(ctx context.Context, s *session, serviceName string) ( } type client struct { - c *http.Client + c *http.Client + transports *lru.Cache + m sync.RWMutex } -// DefaultClient is the default HTTP client, which uses `http.DefaultClient`. -var DefaultClient = NewClient(nil) +// ClientOptions holds user configurable options for the client. +type ClientOptions struct { + // CacheMaxEntries is the max no. of entries that the transport objects + // cache will hold at any given point of time. It must be a positive integer. + // Calling `client.addTransport()` after the cache has reached the specified + // size, will result in the least recently used transport getting deleted + // before the provided transport is added to the cache. + CacheMaxEntries int +} + +var ( + // defaultTransportCacheSize is the default capacity of the transport objects cache. + // Its value is 0 because transport caching is turned off by default and is an + // opt-in feature. + defaultTransportCacheSize = 0 + + // DefaultClient is the default HTTP client, which uses a net/http client configured + // with http.DefaultTransport. + DefaultClient = NewClient(nil) +) // NewClient creates a new client with a custom net/http client. // See `InstallProtocol` to install and override default http client. -// Unless a properly initialized client is given, it will fall back into -// `http.DefaultClient`. +// If the net/http client is nil or empty, it will use a net/http client configured +// with http.DefaultTransport. // // Note that for HTTP client cannot distinguish between private repositories and // unexistent repositories on GitHub. So it returns `ErrAuthorizationRequired` // for both. func NewClient(c *http.Client) transport.Transport { if c == nil { - return &client{http.DefaultClient} + c = &http.Client{ + Transport: http.DefaultTransport, + } } + return NewClientWithOptions(c, &ClientOptions{ + CacheMaxEntries: defaultTransportCacheSize, + }) +} - return &client{ +// NewClientWithOptions returns a new client configured with the provided net/http client +// and other custom options specific to the client. +// If the net/http client is nil or empty, it will use a net/http client configured +// with http.DefaultTransport. +func NewClientWithOptions(c *http.Client, opts *ClientOptions) transport.Transport { + if c == nil { + c = &http.Client{ + Transport: http.DefaultTransport, + } + } + cl := &client{ c: c, } + + if opts != nil { + if opts.CacheMaxEntries > 0 { + cl.transports = lru.New(opts.CacheMaxEntries) + } + } + return cl } func (c *client) NewUploadPackSession(ep *transport.Endpoint, auth transport.AuthMethod) ( transport.UploadPackSession, error) { - return newUploadPackSession(c.c, ep, auth) + return newUploadPackSession(c, ep, auth) } func (c *client) NewReceivePackSession(ep *transport.Endpoint, auth transport.AuthMethod) ( transport.ReceivePackSession, error) { - return newReceivePackSession(c.c, ep, auth) + return newReceivePackSession(c, ep, auth) } type session struct { @@ -117,10 +165,87 @@ type session struct { advRefs *packp.AdvRefs } -func newSession(c *http.Client, ep *transport.Endpoint, auth transport.AuthMethod) (*session, error) { +func transportWithInsecureTLS(transport *http.Transport) { + if transport.TLSClientConfig == nil { + transport.TLSClientConfig = &tls.Config{} + } + transport.TLSClientConfig.InsecureSkipVerify = true +} + +func transportWithCABundle(transport *http.Transport, caBundle []byte) error { + rootCAs, err := x509.SystemCertPool() + if err != nil { + return err + } + if rootCAs == nil { + rootCAs = x509.NewCertPool() + } + rootCAs.AppendCertsFromPEM(caBundle) + if transport.TLSClientConfig == nil { + transport.TLSClientConfig = &tls.Config{} + } + transport.TLSClientConfig.RootCAs = rootCAs + return nil +} + +func configureTransport(transport *http.Transport, ep *transport.Endpoint) error { + if len(ep.CaBundle) > 0 { + if err := transportWithCABundle(transport, ep.CaBundle); err != nil { + return err + } + } + if ep.InsecureSkipTLS { + transportWithInsecureTLS(transport) + } + return nil +} + +func newSession(c *client, ep *transport.Endpoint, auth transport.AuthMethod) (*session, error) { + var httpClient *http.Client + + // We need to configure the http transport if there are transport specific + // options present in the endpoint. + if len(ep.CaBundle) > 0 || ep.InsecureSkipTLS { + var transport *http.Transport + // if the client wasn't configured to have a cache for transports then just configure + // the transport and use it directly, otherwise try to use the cache. + if c.transports == nil { + tr, ok := c.c.Transport.(*http.Transport) + if !ok { + return nil, fmt.Errorf("expected underlying client transport to be of type: %s; got: %s", + reflect.TypeOf(transport), reflect.TypeOf(c.c.Transport)) + } + + transport = tr.Clone() + configureTransport(transport, ep) + } else { + transportOpts := transportOptions{ + caBundle: string(ep.CaBundle), + insecureSkipTLS: ep.InsecureSkipTLS, + } + var found bool + transport, found = c.fetchTransport(transportOpts) + + if !found { + transport = c.c.Transport.(*http.Transport).Clone() + configureTransport(transport, ep) + c.addTransport(transportOpts, transport) + } + } + + httpClient = &http.Client{ + Transport: transport, + CheckRedirect: c.c.CheckRedirect, + Jar: c.c.Jar, + Timeout: c.c.Timeout, + } + } else { + httpClient = c.c + } + s := &session{ auth: basicAuthFromEndpoint(ep), - client: c, + client: httpClient, endpoint: ep, } if auth != nil { -- cgit