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test ok
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@kellerza
kellerza committed May 25, 2021
1 parent f51b5e0 commit 8441f0a
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Showing 13 changed files with 292 additions and 93 deletions.
225 changes: 166 additions & 59 deletions clab/config/ssh.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@ package config
import (
"fmt"
"io"
"runtime"
"strings"
"time"

Expand Down Expand Up @@ -31,47 +32,34 @@ type SshTransport struct {
ses *SshSession
// Contains the first read after connecting
LoginMessage SshReply

ConfigStart func(s *SshTransport)
ConfigCommit func(s *SshTransport) SshReply

// SSH parameters used in connect
// defualt: 22
Port int
// extra debug print
debug bool

// SSH Options
// required!
SshConfig *ssh.ClientConfig

// Character to split the incoming stream (#/$/>)
// default: #
PromptChar string
// Prompt parsing function. Default return the last line of the #
// default: DefaultPrompParse
PromptParse func(in *string) *SshReply
}

// This is the default prompt parse function used by SSH transport
func DefaultPrompParse(in *string) *SshReply {
n := strings.LastIndex(*in, "\n")
if strings.Contains((*in)[n:], " ") {
return &SshReply{
result: *in,
prompt: "",
}
}
res := (*in)[:n]
n = strings.LastIndex(res, "\n")
if n < 0 {
n = 0
}
return &SshReply{
result: (*in)[:n],
prompt: (*in)[n:] + "#",
}
// Kind specific transactions & prompt checking function
K SshKind
}

// The channel does
// Creates the channel reading the SSH connection
//
// The first prompt is saved in LoginMessages
//
// - The channel read the SSH session, splits on PromptChar
// - Uses SshKind's PromptParse to split the received data in *result* and *prompt* parts
// (if no valid prompt was found, prompt will simply be empty and result contain all the data)
// - Emit data
func (t *SshTransport) InChannel() {
// Ensure we have one working channel
// Ensure we have a working channel
t.in = make(chan SshReply)

// setup a buffered string channel
Expand All @@ -88,7 +76,7 @@ func (t *SshTransport) InChannel() {
parts := strings.Split(tmpS, "#")
li := len(parts) - 1
for i := 0; i < li; i++ {
t.in <- *t.PromptParse(&parts[i])
t.in <- *t.K.PromptParse(t, &parts[i])
}
tmpS = parts[li]
}
Expand All @@ -102,11 +90,11 @@ func (t *SshTransport) InChannel() {
}
}()

// Save first prompt
t.LoginMessage = t.Run("", 15)
if LoginMessages {
log.Infof("%s\n", t.LoginMessage.result)
t.LoginMessage.Infof("")
}
//log.Debugf("%s\n", t.BootMsg.prompt)
}

// Run a single command and wait for the reply
Expand All @@ -119,11 +107,17 @@ func (t *SshTransport) Run(command string, timeout int) SshReply {

for {
// Read from the channel with a timeout
var rr string

select {
case <-time.After(time.Duration(timeout) * time.Second):
log.Warnf("timeout waiting for prompt: %s", command)
return SshReply{}
case ret := <-t.in:
if t.debug {
ret.Debug()
}

if ret.prompt == "" && ret.result != "" {
// we should continue reading...
sHistory += ret.result
Expand All @@ -134,23 +128,26 @@ func (t *SshTransport) Run(command string, timeout int) SshReply {
log.Errorf("received zero?")
continue
}
rr := strings.Trim(ret.result, " \n")
if sHistory != "" {
rr = sHistory + rr

if sHistory == "" {
rr = strings.Trim(ret.result, " \n\r\t")
} else {
rr = strings.Trim(sHistory+ret.result, " \n\r\t")
sHistory = ""
}

if strings.HasPrefix(rr, command) {
rr = strings.Trim(rr[len(command):], " \n\r")
// fmt.Print(rr)
rr = strings.Trim(rr[len(command):], " \n\r\t")
} else if !strings.Contains(rr, command) {
sHistory = rr
continue
}
return SshReply{
res := SshReply{
result: rr,
prompt: ret.prompt,
}
res.Debug()
return res
}
}
}
Expand All @@ -159,35 +156,46 @@ func (t *SshTransport) Run(command string, timeout int) SshReply {
// Session NEEDS to be configurable for other kinds
// Part of the Transport interface
func (t *SshTransport) Write(snip *ConfigSnippet) error {
if t.ConfigStart == nil {
return fmt.Errorf("SSH Transport not ready %s", snip.TargetNode.Kind)
if len(snip.Data) == 0 {
return nil
}

transaction := !strings.HasPrefix(snip.templateName, "show-")

err := t.K.ConfigStart(t, snip.TargetNode.ShortName, transaction)
if err != nil {
return err
}
t.ConfigStart(t)

c, b := 0, 0
var r SshReply

for _, l := range snip.Lines() {
l = strings.TrimSpace(l)
if l == "" || strings.HasPrefix(l, "#") {
continue
}
c += 1
b += len(l)
t.Run(l, 3)
r = t.Run(l, 5)
if r.result != "" {
r.Infof(snip.TargetNode.ShortName)
}
}

commit := t.ConfigCommit(t)
if transaction {
commit, _ := t.K.ConfigCommit(t)

commit.Infof("COMMIT %s - %d lines %d bytes", snip, c, b)
}

log.Infof("COMMIT %s - %d lines %d bytes\n%s", snip, c, b, commit.result)
return nil
}

// Connect to a host
// Part of the Transport interface
func (t *SshTransport) Connect(host string) error {
// Assign Default Values
if t.PromptParse == nil {
t.PromptParse = DefaultPrompParse
}
if t.PromptChar == "" {
t.PromptChar = "#"
}
Expand Down Expand Up @@ -262,6 +270,20 @@ func NewSshSession(host string, sshConfig *ssh.ClientConfig) (*SshSession, error
if err != nil {
return nil, fmt.Errorf("session stdin: %s", err)
}
// sshIn2, err := session.StderrPipe()
// if err != nil {
// return nil, fmt.Errorf("session stderr: %s", err)
// }
// Request PTY (required for srl)
modes := ssh.TerminalModes{
ssh.ECHO: 1, // disable echo
}
err = session.RequestPty("dumb", 24, 100, modes)
if err != nil {
session.Close()
return nil, fmt.Errorf("pty request failed: %s", err)
}

if err := session.Shell(); err != nil {
session.Close()
return nil, fmt.Errorf("session shell: %s", err)
Expand All @@ -283,23 +305,108 @@ func (ses *SshSession) Close() {
ses.Session.Close()
}

func (s *SshTransport) SetupKind(kind string) {
switch kind {
case "srl":
s.ConfigStart = func(s *SshTransport) {
s.Run("enter candidate", 10)
// This is a helper funciton to parse the prompt, and can be used by SshKind's ParsePrompt
// Used in SROS & SRL today
func promptParseNoSpaces(in *string, promptChar string, lines int) *SshReply {
n := strings.LastIndex(*in, "\n")
if n < 0 {
return &SshReply{
result: *in,
prompt: "",
}
s.ConfigCommit = func(s *SshTransport) SshReply {
return s.Run("commit now", 10)

}
if strings.Contains((*in)[n:], " ") {
return &SshReply{
result: *in,
prompt: "",
}
case "vr-sros":
s.ConfigStart = func(s *SshTransport) {
s.Run("/configure global", 2)
s.Run("discard", 1)
}
if lines > 1 {
// Add another line to the prompt
res := (*in)[:n]
n = strings.LastIndex(res, "\n")
}
if n < 0 {
n = 0
}
return &SshReply{
result: (*in)[:n],
prompt: (*in)[n:] + promptChar,
}
}

// an interface to implement kind specific methods for transactions and prompt checking
type SshKind interface {
// Start a config transaction
ConfigStart(s *SshTransport, node string, transaction bool) error
// Commit a config transaction
ConfigCommit(s *SshTransport) (SshReply, error)
// Prompt parsing function.
// This function receives string, split by the delimiter and should ensure this is a valid prompt
// Valid prompt, strip te prompt from the result and add it to the prompt in SshReply
//
// A defualt implementation is promptParseNoSpaces, which simply ensures there are
// no spaces between the start of the line and the #
PromptParse(s *SshTransport, in *string) *SshReply
}

// implements SShKind
type VrSrosSshKind struct{}

func (sk *VrSrosSshKind) ConfigStart(s *SshTransport, node string, transaction bool) error {
s.PromptChar = "#" // ensure it's '#'
//s.debug = true
if transaction {
cc := s.Run("/configure global", 5)
if cc.result != "" {
cc.Infof(node)
}
s.ConfigCommit = func(s *SshTransport) SshReply {
return s.Run("commit", 10)
cc = s.Run("discard", 1)
if cc.result != "" {
cc.Infof("%s discard", node)
}
} else {
s.Run("/environment more false", 5)
}
return nil
}
func (sk *VrSrosSshKind) ConfigCommit(s *SshTransport) (SshReply, error) {
return s.Run("commit", 10), nil
}
func (sk *VrSrosSshKind) PromptParse(s *SshTransport, in *string) *SshReply {
return promptParseNoSpaces(in, s.PromptChar, 2)
}

// implements SShKind
type SrlSshKind struct{}

func (sk *SrlSshKind) ConfigStart(s *SshTransport, node string, transaction bool) error {
s.PromptChar = "#" // ensure it's '#'
s.debug = true
if transaction {
s.Run("enter candidate", 5)
s.Run("discard stay", 2)
}
return nil
}
func (sk *SrlSshKind) ConfigCommit(s *SshTransport) (SshReply, error) {
return s.Run("commit now", 10), nil
}
func (sk *SrlSshKind) PromptParse(s *SshTransport, in *string) *SshReply {
return promptParseNoSpaces(in, s.PromptChar, 2)
}

func (r *SshReply) Debug() {
_, fn, line, _ := runtime.Caller(1)
log.Debugf("(%s line %d) *RESULT: %s.\n | %v\n*PROMPT:%v.\n*PROMPT:%v.\n", fn, line, r.result, []byte(r.result), r.prompt, []byte(r.prompt))
}

func (r *SshReply) Infof(msg string, args ...interface{}) {
var s string
if r.result != "" {
s = "\n | "
s += strings.Join(strings.Split(r.result, "\n"), s)
}
log.Infof(msg+s, args...)
}
17 changes: 11 additions & 6 deletions clab/config/template.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -51,13 +51,15 @@ func (c *ConfigSnippet) Render() error {
buf := new(strings.Builder)
c.Data = nil

varsP, _ := json.MarshalIndent(c.vars, "", " ")
log.Debugf("Render %s vars=%s\n", c.String(), varsP)
varsP, err := json.MarshalIndent(c.vars, "", " ")
if err != nil {
varsP = []byte(fmt.Sprintf("%s", c.vars))
}

err := t.ExecuteTemplate(buf, c.templateName, c.vars)
err = t.ExecuteTemplate(buf, c.templateName, c.vars)
if err != nil {
log.Errorf("could not render template: %s %s vars=%s\n", c.String(), err, varsP)
return fmt.Errorf("could not render template: %s %s", c.String(), err)
log.Errorf("could not render template %s: %s vars=%s\n", c.String(), err, varsP)
return fmt.Errorf("could not render template %s: %s", c.String(), err)
}

// Strip blank lines
Expand Down Expand Up @@ -182,7 +184,10 @@ func (c *ConfigSnippet) Lines() []string {

// Print the configSnippet
func (c *ConfigSnippet) Print(printLines int) {
vars, _ := json.MarshalIndent(c.vars, "", " ")
vars := []byte{}
if log.IsLevelEnabled(log.DebugLevel) {
vars, _ = json.MarshalIndent(c.vars, "", " ")
}

s := ""
if printLines > 0 {
Expand Down
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