podman ssh work, using new c/common interface

implement new ssh interface into podman

this completely redesigns the entire functionality of podman image scp,
podman system connection add, and podman --remote. All references to golang.org/x/crypto/ssh
have been moved to common as have native ssh/scp execs and the new usage of the sftp package.

this PR adds a global flag, --ssh to podman which has two valid inputs `golang` and `native` where golang is the default.
Users should not notice any difference in their everyday workflows if they continue using the golang option. UNLESS they have been using an improperly verified ssh key, this will now fail. This is because podman was incorrectly using the
ssh callback method to IGNORE the ssh known hosts file which is very insecure and golang tells you not yo use this in production.

The native paths allows for immense flexibility, with a new containers.conf field `SSH_CONFIG` that specifies a specific ssh config file to be used in all operations. Else the users ~/.ssh/config file will be used.
podman --remote currently only uses the golang path, given its deep interconnection with dialing multiple clients and urls.

My goal after this PR is to go back and abstract the idea of podman --remote from golang's dialed clients, as it should not be so intrinsically connected. Overall, this is a v1 of a long process of offering native ssh, and one that covers some good ground with podman system connection add and podman image scp.

Signed-off-by: Charlie Doern <cdoern@redhat.com>

1 files changed, 137 insertions, 0 deletions

diff --git a/vendor/github.com/pkg/sftp/match.go b/vendor/github.com/pkg/sftp/match.go
new file mode 100644
index 000000000..875006afd
--- /dev/null
+++ b/vendor/github.com/pkg/sftp/match.go
@@ -0,0 +1,137 @@
+package sftp
+
+import (
+	"path"
+	"strings"
+)
+
+// ErrBadPattern indicates a globbing pattern was malformed.
+var ErrBadPattern = path.ErrBadPattern
+
+// Match reports whether name matches the shell pattern.
+//
+// This is an alias for path.Match from the standard library,
+// offered so that callers need not import the path package.
+// For details, see https://golang.org/pkg/path/#Match.
+func Match(pattern, name string) (matched bool, err error) {
+	return path.Match(pattern, name)
+}
+
+// detect if byte(char) is path separator
+func isPathSeparator(c byte) bool {
+	return c == '/'
+}
+
+// Split splits the path p immediately following the final slash,
+// separating it into a directory and file name component.
+//
+// This is an alias for path.Split from the standard library,
+// offered so that callers need not import the path package.
+// For details, see https://golang.org/pkg/path/#Split.
+func Split(p string) (dir, file string) {
+	return path.Split(p)
+}
+
+// Glob returns the names of all files matching pattern or nil
+// if there is no matching file. The syntax of patterns is the same
+// as in Match. The pattern may describe hierarchical names such as
+// /usr/*/bin/ed.
+//
+// Glob ignores file system errors such as I/O errors reading directories.
+// The only possible returned error is ErrBadPattern, when pattern
+// is malformed.
+func (c *Client) Glob(pattern string) (matches []string, err error) {
+	if !hasMeta(pattern) {
+		file, err := c.Lstat(pattern)
+		if err != nil {
+			return nil, nil
+		}
+		dir, _ := Split(pattern)
+		dir = cleanGlobPath(dir)
+		return []string{Join(dir, file.Name())}, nil
+	}
+
+	dir, file := Split(pattern)
+	dir = cleanGlobPath(dir)
+
+	if !hasMeta(dir) {
+		return c.glob(dir, file, nil)
+	}
+
+	// Prevent infinite recursion. See issue 15879.
+	if dir == pattern {
+		return nil, ErrBadPattern
+	}
+
+	var m []string
+	m, err = c.Glob(dir)
+	if err != nil {
+		return
+	}
+	for _, d := range m {
+		matches, err = c.glob(d, file, matches)
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+// cleanGlobPath prepares path for glob matching.
+func cleanGlobPath(path string) string {
+	switch path {
+	case "":
+		return "."
+	case "/":
+		return path
+	default:
+		return path[0 : len(path)-1] // chop off trailing separator
+	}
+}
+
+// glob searches for files matching pattern in the directory dir
+// and appends them to matches. If the directory cannot be
+// opened, it returns the existing matches. New matches are
+// added in lexicographical order.
+func (c *Client) glob(dir, pattern string, matches []string) (m []string, e error) {
+	m = matches
+	fi, err := c.Stat(dir)
+	if err != nil {
+		return
+	}
+	if !fi.IsDir() {
+		return
+	}
+	names, err := c.ReadDir(dir)
+	if err != nil {
+		return
+	}
+	//sort.Strings(names)
+
+	for _, n := range names {
+		matched, err := Match(pattern, n.Name())
+		if err != nil {
+			return m, err
+		}
+		if matched {
+			m = append(m, Join(dir, n.Name()))
+		}
+	}
+	return
+}
+
+// Join joins any number of path elements into a single path, separating
+// them with slashes.
+//
+// This is an alias for path.Join from the standard library,
+// offered so that callers need not import the path package.
+// For details, see https://golang.org/pkg/path/#Join.
+func Join(elem ...string) string {
+	return path.Join(elem...)
+}
+
+// hasMeta reports whether path contains any of the magic characters
+// recognized by Match.
+func hasMeta(path string) bool {
+	return strings.ContainsAny(path, "\\*?[")
+}