V2 podman system connection

* Implement command
* Refactor podman-remote to pull from containers.conf by default
* podman-remote defaults to --remote being true
* Write podman-system-connection.1.md

Signed-off-by: Jhon Honce <jhonce@redhat.com>

1 files changed, 133 insertions, 0 deletions

diff --git a/pkg/terminal/util.go b/pkg/terminal/util.go
new file mode 100644
index 000000000..ab3dc54e4
--- /dev/null
+++ b/pkg/terminal/util.go
@@ -0,0 +1,133 @@
+package terminal
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sync"
+
+	"github.com/sirupsen/logrus"
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/terminal"
+	"k8s.io/client-go/util/homedir"
+)
+
+var (
+	passPhrase   []byte
+	phraseSync   sync.Once
+	password     []byte
+	passwordSync sync.Once
+)
+
+// ReadPassword prompts for a secret and returns value input by user from stdin
+// Unlike terminal.ReadPassword(), $(echo $SECRET | podman...) is supported.
+// Additionally, all input after `<secret>/n` is queued to podman command.
+func ReadPassword(prompt string) (pw []byte, err error) {
+	fd := int(os.Stdin.Fd())
+	if terminal.IsTerminal(fd) {
+		fmt.Fprint(os.Stderr, prompt)
+		pw, err = terminal.ReadPassword(fd)
+		fmt.Fprintln(os.Stderr)
+		return
+	}
+
+	var b [1]byte
+	for {
+		n, err := os.Stdin.Read(b[:])
+		// terminal.ReadPassword discards any '\r', so we do the same
+		if n > 0 && b[0] != '\r' {
+			if b[0] == '\n' {
+				return pw, nil
+			}
+			pw = append(pw, b[0])
+			// limit size, so that a wrong input won't fill up the memory
+			if len(pw) > 1024 {
+				err = errors.New("password too long, 1024 byte limit")
+			}
+		}
+		if err != nil {
+			// terminal.ReadPassword accepts EOF-terminated passwords
+			// if non-empty, so we do the same
+			if err == io.EOF && len(pw) > 0 {
+				err = nil
+			}
+			return pw, err
+		}
+	}
+}
+
+func PublicKey(path string, passphrase []byte) (ssh.AuthMethod, error) {
+	key, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	signer, err := ssh.ParsePrivateKey(key)
+	if err != nil {
+		if _, ok := err.(*ssh.PassphraseMissingError); !ok {
+			return nil, err
+		}
+		if len(passphrase) == 0 {
+			passphrase = ReadPassphrase()
+		}
+		signer, err = ssh.ParsePrivateKeyWithPassphrase(key, passphrase)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return ssh.PublicKeys(signer), nil
+}
+
+func ReadPassphrase() []byte {
+	phraseSync.Do(func() {
+		secret, err := ReadPassword("Key Passphrase: ")
+		if err != nil {
+			secret = []byte{}
+		}
+		passPhrase = secret
+	})
+	return passPhrase
+}
+
+func ReadLogin() []byte {
+	passwordSync.Do(func() {
+		secret, err := ReadPassword("Login password: ")
+		if err != nil {
+			secret = []byte{}
+		}
+		password = secret
+	})
+	return password
+}
+
+func HostKey(host string) ssh.PublicKey {
+	// parse OpenSSH known_hosts file
+	// ssh or use ssh-keyscan to get initial key
+	knownHosts := filepath.Join(homedir.HomeDir(), ".ssh", "known_hosts")
+	fd, err := os.Open(knownHosts)
+	if err != nil {
+		logrus.Error(err)
+		return nil
+	}
+
+	scanner := bufio.NewScanner(fd)
+	for scanner.Scan() {
+		_, hosts, key, _, _, err := ssh.ParseKnownHosts(scanner.Bytes())
+		if err != nil {
+			logrus.Errorf("Failed to parse known_hosts: %s", scanner.Text())
+			continue
+		}
+
+		for _, h := range hosts {
+			if h == host {
+				return key
+			}
+		}
+	}
+
+	return nil
+}