{"record":{"id":"dc15f8607a4dff33","repo":"kubernetes/kops","slug":"forwarding-ssh-auth-to-keyring-w","errorCode":null,"errorMessage":"forwarding ssh auth to keyring: %w","messagePattern":"forwarding ssh auth to keyring: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/dump/dumper.go","lineNumber":704,"sourceCode":"\t\tTimeout: 5 * time.Second,\n\t}\n\tconn, err := d.DialContext(ctx, \"tcp\", addr)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"error dialing tcp %s: %w\", addr, err)\n\t}\n\n\t// We have a TCP connection; we will force-close it to support context cancellation\n\n\tvar client *ssh.Client\n\tfinished := make(chan error)\n\tgo func() {\n\t\tc, chans, reqs, err := ssh.NewClientConn(conn, addr, f.sshConfig)\n\t\tif err == nil {\n\t\t\tclient = ssh.NewClient(c, chans, reqs)\n\t\t\tif useBastion {\n\t\t\t\terr = agent.ForwardToAgent(client, f.keyRing)\n\t\t\t\tif err != nil {\n\t\t\t\t\terr = fmt.Errorf(\"forwarding ssh auth to keyring: %w\", err)\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\n\t\tif err == nil && useBastion {\n\t\t\tsession, err := client.NewSession()\n\t\t\tif err != nil {\n\t\t\t\tfinished <- fmt.Errorf(\"creating ssh session: %w\", err)\n\t\t\t\treturn\n\t\t\t}\n\t\t\tdefer session.Close()\n\n\t\t\terr = agent.RequestAgentForwarding(session)\n\t\t\tif err != nil {\n\t\t\t\tfinished <- fmt.Errorf(\"requesting agent forwarding: %w\", err)\n\t\t\t\treturn\n\t\t\t}\n\t\t}","sourceCodeStart":686,"sourceCodeEnd":722,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/pkg/dump/dumper.go#L686-L722","documentation":"When Dial connects through a bastion (useBastion=true), it forwards SSH agent authentication to the keyring via agent.ForwardToAgent on the established client. If that forwarding call fails, the error is wrapped with this message and returned from Dial. It means the TCP+SSH handshake succeeded but agent forwarding setup over the client failed.","triggerScenarios":"agent.ForwardToAgent(client, f.keyRing) returns an error while establishing a bastion-routed connection — typically because the keyring (agent.Agent) is nil or misconfigured, or the ssh.Client connection broke immediately after handshake.","commonSituations":"Dumping via bastion when the caller's SSH agent/keyring was not initialized (no keyring passed to the factory); connection to the bastion dropped mid-setup; incompatible agent implementation.","solutions":["Ensure the sshClientFactory is constructed with a valid keyRing (agent.Agent) and that your local ssh-agent is running with the right keys loaded (ssh-add -l)","Verify SSH connectivity/auth to the bastion itself (ssh -A user@bastion) to rule out a broken handshake","If the keyring is intentionally unused, avoid the bastion path (useBastion=false) or fix the factory wiring so keyRing is set"],"exampleFix":"// before\nfactory := &sshClientFactoryImplementation{bastion: bastionHost, sshConfig: cfg} // keyRing missing\n\n// after\nkeyring := agent.NewKeyring() // or the local agent\nfactory := &sshClientFactoryImplementation{bastion: bastionHost, sshConfig: cfg, keyRing: keyring}","handlingStrategy":"try-catch","validationCode":"if keyRing == nil {\n\treturn fmt.Errorf(\"keyring must be configured for bastion-routed SSH\")\n}\nout, err := exec.Command(\"ssh-add\", \"-l\").Output()\nif err != nil {\n\treturn fmt.Errorf(\"no ssh-agent keys available: %w\", err)\n}","typeGuard":"func hasKeyRing(f *sshClientFactoryImplementation) bool { return f.keyRing != nil }","tryCatchPattern":"client, err := factory.Dial(ctx, host, true)\nif err != nil && strings.Contains(err.Error(), \"forwarding ssh auth to keyring\") {\n\treturn fmt.Errorf(\"ssh agent forwarding setup failed; check ssh-agent/keys: %w\", err)\n}","preventionTips":["Run ssh-agent with keys loaded (ssh-add) before bastion dumps","Always initialize keyRing when constructing the factory for bastion use","Test bastion auth with ssh -A user@bastion before automation"],"tags":["ssh","agent-forwarding","bastion"],"backgroundTag":"ssh-agent-forwarding-failed","analyzedSha":"4c8573c808a73d578c5eadc86d410646ea0b0d73","analyzedAt":"2026-09-05T04:13:19.212Z","contentChangedAt":"2026-09-05T04:13:19.212Z","schemaVersion":2},"datasetVersion":"2026-09-12T07:17:12.445Z"}