3b5e814242
The "github.com/docker/distribution" module moved to the distribution
org ("github.com/docker/distribution/v3"), and the new module deprecated
and removed the uuid package in favor of Google's UUID package.
While we still depend on the old module through packages and as an indirect
dependency, we may want to try avoid using it.
This patch replaces the use for the socket package, and replaces it for a
local utility, taking the same approach as `stringid.GenerateRandomID()`,
which should be random enough for this purpose.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
81 lines
2.0 KiB
Go
81 lines
2.0 KiB
Go
package socket
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import (
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"crypto/rand"
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"encoding/hex"
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"errors"
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"io"
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"net"
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"os"
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)
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// EnvKey represents the well-known environment variable used to pass the plugin being
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// executed the socket name it should listen on to coordinate with the host CLI.
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const EnvKey = "DOCKER_CLI_PLUGIN_SOCKET"
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// SetupConn sets up a Unix socket listener, establishes a goroutine to handle connections
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// and update the conn pointer, and returns the listener for the socket (which the caller
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// is responsible for closing when it's no longer needed).
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func SetupConn(conn **net.UnixConn) (*net.UnixListener, error) {
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listener, err := listen("docker_cli_" + randomID())
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if err != nil {
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return nil, err
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}
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accept(listener, conn)
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return listener, nil
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}
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func randomID() string {
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b := make([]byte, 16)
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if _, err := rand.Read(b); err != nil {
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panic(err) // This shouldn't happen
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}
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return hex.EncodeToString(b)
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}
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func accept(listener *net.UnixListener, conn **net.UnixConn) {
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go func() {
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for {
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// ignore error here, if we failed to accept a connection,
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// conn is nil and we fallback to previous behavior
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*conn, _ = listener.AcceptUnix()
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// perform any platform-specific actions on accept (e.g. unlink non-abstract sockets)
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onAccept(*conn, listener)
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}
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}()
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}
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// ConnectAndWait connects to the socket passed via well-known env var,
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// if present, and attempts to read from it until it receives an EOF, at which
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// point cb is called.
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func ConnectAndWait(cb func()) {
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socketAddr, ok := os.LookupEnv(EnvKey)
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if !ok {
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// if a plugin compiled against a more recent version of docker/cli
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// is executed by an older CLI binary, ignore missing environment
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// variable and behave as usual
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return
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}
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addr, err := net.ResolveUnixAddr("unix", socketAddr)
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if err != nil {
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return
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}
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conn, err := net.DialUnix("unix", nil, addr)
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if err != nil {
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return
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}
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go func() {
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b := make([]byte, 1)
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for {
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_, err := conn.Read(b)
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if errors.Is(err, io.EOF) {
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cb()
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return
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}
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}
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}()
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}
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