feat(provider): add support for ssh-agent on Windows (#1270)

* feat(provider): add support for `ssh-agent` on Windows

Signed-off-by: Brian Karshick <Sparta142@users.noreply.github.com>

docs/index.md

@@ -116,9 +116,11 @@ This allows the provider to use the SSH agent configured by the user, and to sup
 You can find more details on the SSH Agent [here](https://www.digitalocean.com/community/tutorials/ssh-essentials-working-with-ssh-servers-clients-and-keys#adding-your-ssh-keys-to-an-ssh-agent-to-avoid-typing-the-passphrase).
 The SSH agent authentication takes precedence over the `private_key` and `password` authentication.
 
+-> By default on Windows, the provider will assume the SSH agent is at `\\.\pipe\openssh-ssh-agent`.
+
 ### SSH Private Key
 
-In some cases where SSH agent is not available, for example when running Terraform from a Windows machine, or when using a CI/CD pipeline that does not support SSH agent forwarding, 
+In some cases where SSH agent is not available, for example when using a CI/CD pipeline that does not support SSH agent forwarding, 
 you can use the `private_key` argument in the `ssh` block (or alternatively `PROXMOX_VE_SSH_PRIVATE_KEY` environment variable) to provide the private key for the SSH connection.
 
 The private key mut not be encrypted, and must be in PEM format.

go.mod

@@ -5,6 +5,7 @@ go 1.22
 toolchain go1.22.3
 
 require (
+	github.com/Microsoft/go-winio v0.6.2
 	github.com/avast/retry-go/v4 v4.6.0
 	github.com/brianvoe/gofakeit/v7 v7.0.3
 	github.com/google/go-cmp v0.6.0

go.sum

@@ -1,7 +1,7 @@
 dario.cat/mergo v1.0.0 h1:AGCNq9Evsj31mOgNPcLyXc+4PNABt905YmuqPYYpBWk=
 dario.cat/mergo v1.0.0/go.mod h1:uNxQE+84aUszobStD9th8a29P2fMDhsBdgRYvZOxGmk=
-github.com/Microsoft/go-winio v0.6.1 h1:9/kr64B9VUZrLm5YYwbGtUJnMgqWVOdUAXu6Migciow=
+github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERoyfY=
-github.com/Microsoft/go-winio v0.6.1/go.mod h1:LRdKpFKfdobln8UmuiYcKPot9D2v6svN5+sAH+4kjUM=
+github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
 github.com/ProtonMail/go-crypto v1.1.0-alpha.0 h1:nHGfwXmFvJrSR9xu8qL7BkO4DqTHXE9N5vPhgY2I+j0=
 github.com/ProtonMail/go-crypto v1.1.0-alpha.0/go.mod h1:rA3QumHc/FZ8pAHreoekgiAbzpNsfQAosU5td4SnOrE=
 github.com/agext/levenshtein v1.2.3 h1:YB2fHEn0UJagG8T1rrWknE3ZQzWM06O8AMAatNn7lmo=

proxmox/ssh/client.go

@@ -78,9 +78,13 @@ func NewClient(
 	socks5Server string, socks5Username string, socks5Password string,
 	nodeResolver NodeResolver,
 ) (Client, error) {
-	if agent && runtime.GOOS != "linux" && runtime.GOOS != "darwin" && runtime.GOOS != "freebsd" {
+	if agent &&
+		runtime.GOOS != "linux" &&
+		runtime.GOOS != "darwin" &&
+		runtime.GOOS != "freebsd" &&
+		runtime.GOOS != "windows" {
 		return nil, errors.New(
-			"the ssh agent flag is only supported on POSIX systems, please set it to 'false'" +
+			"the ssh agent flag is only supported on POSIX and Windows systems, please set it to 'false'" +
 				" or remove it from your provider configuration",
 		)
 	}
@@ -531,12 +535,7 @@ func (c *client) createSSHClientAgent(
 	kh knownhosts.HostKeyCallback,
 	sshHost string,
 ) (*ssh.Client, error) {
-	if c.agentSocket == "" {
+	conn, err := dialSocket(c.agentSocket)
-		return nil, errors.New("failed connecting to SSH agent socket: the socket file is not defined, " +
-			"authentication will fall back to password")
-	}
-
-	conn, err := net.Dial("unix", c.agentSocket)
 	if err != nil {
 		return nil, fmt.Errorf("failed connecting to SSH auth socket '%s': %w", c.agentSocket, err)
 	}

proxmox/ssh/client_notwindows.go

@@ -0,0 +1,24 @@
+//go:build !windows
+
+package ssh
+
+import (
+	"errors"
+	"fmt"
+	"net"
+)
+
+// dialSocket dials a Unix domain socket.
+func dialSocket(address string) (net.Conn, error) {
+	if address == "" {
+		return nil, errors.New("failed connecting to SSH agent socket: the socket file is not defined, " +
+			"authentication will fall back to password")
+	}
+
+	conn, err := net.Dial("unix", address)
+	if err != nil {
+		return nil, fmt.Errorf("error dialing unix socket: %w", err)
+	}
+
+	return conn, nil
+}

proxmox/ssh/client_windows.go

@@ -0,0 +1,24 @@
+//go:build windows
+
+package ssh
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/Microsoft/go-winio"
+)
+
+// dialSocket dials a Windows named pipe. If address is empty, it dials the default ssh-agent pipe.
+func dialSocket(address string) (net.Conn, error) {
+	if address == "" {
+		address = `\\.\pipe\openssh-ssh-agent`
+	}
+
+	conn, err := winio.DialPipe(address, nil)
+	if err != nil {
+		return nil, fmt.Errorf("error dialing named pipe: %w", err)
+	}
+
+	return conn, nil
+}