Golang Context.Get方法代码示例

// Serve creates a new Cookoo web server.
//
// Important details:
//
// 	- A URIPathResolver is used for resolving request names.
// 	- The following datasources are added to the Context:
// 	  * url: A URLDatasource (Provides access to parts of the URL)
// 	  * path: A PathDatasource (Provides access to parts of a path. E.g. "/foo/bar")
// 	  * query: A QueryParameterDatasource (Provides access to URL query parameters.)
// 	  * post: A FormValuesDatasource (Provides access to form data or the body of a request.)
// 	- The following context variables are set:
// 	  * http.Request: A pointer to the http.Request object
// 	  * http.ResponseWriter: The response writer.
// 	  * server.Address: The server's address and port (NOT ALWAYS PRESENT)
// 	- The handler includes logic to redirect "not found" errors to a path named "@404" if present.
//
// Context Params:
//
// 	- server.Address: If this key exists in the context, it will be used to determine the host/port the
//   server runes on. EXPERIMENTAL. Default is ":8080".
//
// Example:
//
//    package main
//
//    import (
//      //This is the path to Cookoo
//      "github.com/Masterminds/cookoo"
//      "github.com/Masterminds/cookoo/web"
//      "fmt"
//    )
//
//    func main() {
//      // Build a new Cookoo app.
//      registry, router, context := cookoo.Cookoo()
//
//      // Fill the registry.
//      registry.Route("GET /", "The index").Does(web.Flush, "example").
//        Using("content").WithDefault("Hello World")
//
//      // Create a server
//      web.Serve(reg, router, cookoo.SyncContext(cxt))
//    }
//
// Note that we synchronize the context before passing it into Serve(). This
// is optional because each handler gets its own copy of the context already.
// However, if commands pass the context to goroutines, the context ought to be
// synchronized to avoid race conditions.
//
// Note that copies of the context are not synchronized with each other.
// So by declaring the context synchronized here, you
// are not therefore synchronizing across handlers.
func Serve(reg *cookoo.Registry, router *cookoo.Router, cxt cookoo.Context) {
	addr := cxt.Get("server.Address", ":8080").(string)

	handler := NewCookooHandler(reg, router, cxt)

	// MPB: I dont think there's any real point in having a multiplexer in
	// this particular case. The Cookoo handler is mux enough.
	//
	// Note that we can always use Cookoo with the built-in multiplexer. It
	// just doesn't make sense if Cookoo's the only handler on the app.
	//http.Handle("/", handler)

	server := &http.Server{Addr: addr}

	// Instead of mux, set a single default handler.
	// What we might be losing:
	// - Handling of non-conforming paths.
	server.Handler = handler

	go handleSignals(router, cxt, server)
	err := server.ListenAndServe()
	//err := http.ListenAndServe(addr, nil)
	if err != nil {
		cxt.Logf("error", "Caught error while serving: %s", err)
		if router.HasRoute("@crash") {
			router.HandleRequest("@crash", cxt, false)
		}
	}
}

/**
 * Perform authentication.
 *
 * Params:
 * 	- realm (string): The name of the realm. (Default: "web")
 * 	- datasource (string): The name of the datasource that should be used to authenticate.
 * 	  This datasource must be an `auth.UserDatasource`. (Default: "auth.UserDatasource")
 *
 * Context:
 * 	- http.Request (*http.Request): The HTTP request. This is usually placed into the
 * 	context for you.
 * 	- http.ResponseWriter (http.ResponseWriter): The response. This is usually placed
 * 	 into the context for you.
 *
 * Datasource:
 * 	- An auth.UserDatasource. By default, this will look for a datasource named
 * 	  "auth.UserDatasource". This can be overridden by the `datasource` param.
 *
 * Returns:
 * 	- True if the user authenticated. If not, this will send a 401 and then stop
 * 	  the current chain.
 */
func Basic(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
	realm := p.Get("realm", "web").(string)
	dsName := p.Get("datasource", "auth.UserDatasource").(string)

	req := c.Get("http.Request", nil).(*http.Request)
	res := c.Get("http.ResponseWriter", nil).(http.ResponseWriter)

	ds := c.Datasource(dsName).(UserDatasource)

	authz := strings.TrimSpace(req.Header.Get("Authorization"))
	if len(authz) == 0 || !strings.Contains(authz, "Basic ") {
		return sendUnauthorized(realm, res)
	}

	user, pass, err := parseBasicString(authz)
	if err != nil {
		c.Logf("info", "Basic authentication parsing failed: %s", err)
		return sendUnauthorized(realm, res)
	}

	ok, err := ds.AuthUser(user, pass)
	if !ok {
		if err != nil {
			c.Logf("info", "Basic authentication caused an error: %s", err)
		}
		return sendUnauthorized(realm, res)
	}

	return ok, err
}

// ParseHostKeys parses the host key files.
//
// By default it looks in /etc/ssh for host keys of the patterh ssh_host_{{TYPE}}_key.
//
// Params:
// 	- keytypes ([]string): Key types to parse. Defaults to []string{rsa, dsa, ecdsa}
// 	- enableV1 (bool): Allow V1 keys. By default this is disabled.
// 	- path (string): Override the lookup pattern. If %s, it will be replaced with the keytype.
//
// Returns:
// 	[]ssh.Signer
func ParseHostKeys(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
	log.Debugf(c, "Parsing ssh host keys")
	hostKeyTypes := p.Get("keytypes", []string{"rsa", "dsa", "ecdsa"}).([]string)
	pathTpl := p.Get("path", "/etc/ssh/ssh_host_%s_key").(string)
	hostKeys := make([]ssh.Signer, 0, len(hostKeyTypes))
	for _, t := range hostKeyTypes {
		path := fmt.Sprintf(pathTpl, t)

		if key, err := ioutil.ReadFile(path); err == nil {
			if hk, err := ssh.ParsePrivateKey(key); err == nil {
				log.Infof(c, "Parsed host key %s.", path)
				hostKeys = append(hostKeys, hk)
			} else {
				log.Errf(c, "Failed to parse host key %s (skipping): %s", path, err)
			}
		}
	}
	if c.Get("enableV1", false).(bool) {
		path := "/etc/ssh/ssh_host_key"
		if key, err := ioutil.ReadFile(path); err != nil {
			log.Errf(c, "Failed to read ssh_host_key")
		} else if hk, err := ssh.ParsePrivateKey(key); err == nil {
			log.Infof(c, "Parsed host key %s.", path)
			hostKeys = append(hostKeys, hk)
		} else {
			log.Errf(c, "Failed to parse host key %s: %s", path, err)
		}
	}
	return hostKeys, nil
}

// Subscribe allows an request to subscribe to topic updates.
//
// Params:
// 	- topic (string): The topic to subscribe to.
// 	-
//
// Returns:
//
func Subscribe(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
	medium, err := getMedium(c)
	if err != nil {
		return nil, &cookoo.FatalError{"No medium."}
	}
	topic := p.Get("topic", "").(string)
	if len(topic) == 0 {
		return nil, errors.New("No topic is set.")
	}

	rw := c.Get("http.ResponseWriter", nil).(ResponseWriterFlusher)
	clientGone := rw.(http.CloseNotifier).CloseNotify()

	sub := NewSubscription(rw)
	t := fetchOrCreateTopic(medium, topic, true, DefaultMaxHistory)
	t.Subscribe(sub)

	defer func() {
		t.Unsubscribe(sub)
		sub.Close()
	}()

	sub.Listen(clientGone)

	return nil, nil
}

// ReplayHistory sends back the history to a subscriber.
//
// This should be called before the client goes into active listening.
//
// Params:
// - topic (string): The topic to fetch.
//
// Returns:
// 	- int: The number of history messages sent to the client.
func ReplayHistory(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
	req := c.Get("http.Request", nil).(*http.Request)
	res := c.Get("http.ResponseWriter", nil).(ResponseWriterFlusher)
	medium, _ := getMedium(c)
	name := p.Get("topic", "").(string)

	// This does not manage topics. If there is no topic set, we silently fail.
	if len(name) == 0 {
		c.Log("info", "No topic name given to ReplayHistory.")
		return 0, nil
	}
	top, ok := medium.Topic(name)
	if !ok {
		c.Logf("info", "No topic named %s exists yet. No history replayed.", name)
		return 0, nil
	}

	topic, ok := top.(HistoriedTopic)
	if !ok {
		c.Logf("info", "No history for topic %s.", name)
		res.Header().Add(XHistoryEnabled, "False")
		return 0, nil
	}
	res.Header().Add(XHistoryEnabled, "True")

	since := req.Header.Get(XHistorySince)
	max := req.Header.Get(XHistoryLength)

	// maxLen can be used either on its own or paired with X-History-Since.
	maxLen := 0
	if len(max) > 0 {
		m, err := parseHistLen(max)
		if err != nil {
			c.Logf("info", "failed to parse X-History-Length %s", max)
		} else {
			maxLen = m
		}
	}
	if len(since) > 0 {
		ts, err := parseSince(since)
		if err != nil {
			c.Logf("warn", "Failed to parse X-History-Since field %s: %s", since, err)
			return 0, nil
		}
		toSend := topic.Since(ts)

		// If maxLen is also set, we trim the list by sending the newest.
		ls := len(toSend)
		if maxLen > 0 && ls > maxLen {
			offset := ls - maxLen - 1
			toSend = toSend[offset:]
		}
		return sendHistory(c, res, toSend)
	} else if maxLen > 0 {
		toSend := topic.Last(maxLen)
		return sendHistory(c, res, toSend)
	}

	return 0, nil
}

// BufferPost buffers the body of the POST request into the context.
//
// Params:
//
// Returns:
//	- []byte with the content of the request.
func BufferPost(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
	req := c.Get("http.Request", nil).(*http.Request)
	var b bytes.Buffer
	_, err := io.Copy(&b, req.Body)
	c.Logf("info", "Received POST: %s", b.Bytes())
	return b.Bytes(), err
}

// Show help.
// This command is useful for placing at the front of a CLI "subcommand" to have it output
// help information. It will only trigger when "show" is set to true, so another command
// can, for example, check for a "-h" or "-help" flag and set "show" based on that.
//
// Params:
// 	- show (bool): If `true`, show help.
// 	- summary (string): A one-line summary of the command.
// 	- description (string): A short description of what the command does.
// 	- usage (string): usage information.
// 	- flags (FlagSet): Flags that are supported. The FlagSet will be converted to help text.
// 	- writer (Writer): The location that this will write to. Default is os.Stdout
// 	- subcommands ([]string): A list of subcommands. This will be formatted as help text.
func ShowHelp(cxt cookoo.Context, params *cookoo.Params) (interface{}, cookoo.Interrupt) {
	showHelp := false
	showHelpO := params.Get("show", false)
	switch showHelpO.(type) {
	case string:
		showHelp = strings.ToLower(showHelpO.(string)) == "true"
	case bool:
		showHelp = showHelpO.(bool)
	}

	writer := params.Get("writer", os.Stdout).(io.Writer)

	pmap := params.AsMap()

	// Last resort: If no summary, pull it from the route description.
	if summary, ok := pmap["summary"]; !ok || len(summary.(string)) == 0 {
		pmap["summary"] = cxt.Get("route.Description", "").(string)
	}

	sections := []string{"summary", "description", "usage"}
	if _, ok := params.Has("subcommands"); ok {
		sections = append(sections, "subcommands")
	}

	if showHelp {
		displayHelp(sections, pmap, writer)
		return true, new(cookoo.Stop)
	}

	return false, nil
}

// MergeToYaml converts a Config object and a yaml.File to a single yaml.File.
//
// Params:
//	- conf (*Config): The configuration to merge.
//	- overwriteImports (bool, default true): If this is true, old config will
//		overwritten. If false, we attempt to merge the old and new config, with
//		preference to the old.
//
// Returns:
//	- The root yaml.Node of the modified config.
//
// Uses:
//	- cxt.Get("yaml.File") as the source for the YAML file.
func MergeToYaml(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
	root := c.Get("yaml.File", nil).(*yaml.File).Root
	cfg := p.Get("conf", nil).(*Config)
	overwrite := p.Get("overwriteImports", true).(bool)

	rootMap, ok := root.(yaml.Map)
	if !ok {
		return nil, fmt.Errorf("Expected root node to be a map.")
	}

	if len(cfg.Name) > 0 {
		rootMap["package"] = yaml.Scalar(cfg.Name)
	}
	if cfg.InCommand != "" {
		rootMap["incmd"] = yaml.Scalar(cfg.InCommand)
	}

	if overwrite {
		// Imports
		imports := make([]yaml.Node, len(cfg.Imports))
		for i, imp := range cfg.Imports {
			imports[i] = imp.ToYaml()
		}
		rootMap["import"] = yaml.List(imports)
	} else {
		var err error
		rootMap, err = mergeImports(rootMap, cfg)
		if err != nil {
			Warn("Problem merging imports: %s\n", err)
		}
	}

	return root, nil
}

// Receive receives a Git repo.
// This will only work for git-receive-pack.
//
// Params:
// 	- operation (string): e.g. git-receive-pack
// 	- repoName (string): The repository name, in the form '/REPO.git'.
// 	- channel (ssh.Channel): The channel.
// 	- request (*ssh.Request): The channel.
// 	- gitHome (string): Defaults to /home/git.
// 	- fingerprint (string): The fingerprint of the user's SSH key.
// 	- user (string): The name of the Deis user.
//
// Returns:
// 	- nothing
func Receive(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
	if ok, z := p.Requires("channel", "request", "fingerprint", "permissions"); !ok {
		return nil, fmt.Errorf("Missing requirements %q", z)
	}
	repoName := p.Get("repoName", "").(string)
	operation := p.Get("operation", "").(string)
	channel := p.Get("channel", nil).(ssh.Channel)
	gitHome := p.Get("gitHome", "/home/git").(string)
	fingerprint := p.Get("fingerprint", nil).(string)
	user := p.Get("user", "").(string)

	repo, err := cleanRepoName(repoName)
	if err != nil {
		log.Warnf(c, "Illegal repo name: %s.", err)
		channel.Stderr().Write([]byte("No repo given"))
		return nil, err
	}
	repo += ".git"

	if _, err := createRepo(c, filepath.Join(gitHome, repo), gitHome); err != nil {
		log.Infof(c, "Did not create new repo: %s", err)
	}
	cmd := exec.Command("git-shell", "-c", fmt.Sprintf("%s '%s'", operation, repo))
	log.Infof(c, strings.Join(cmd.Args, " "))

	var errbuff bytes.Buffer

	cmd.Dir = gitHome
	cmd.Env = []string{
		fmt.Sprintf("RECEIVE_USER=%s", user),
		fmt.Sprintf("RECEIVE_REPO=%s", repo),
		fmt.Sprintf("RECEIVE_FINGERPRINT=%s", fingerprint),
		fmt.Sprintf("SSH_ORIGINAL_COMMAND=%s '%s'", operation, repo),
		fmt.Sprintf("SSH_CONNECTION=%s", c.Get("SSH_CONNECTION", "0 0 0 0").(string)),
	}
	cmd.Env = append(cmd.Env, os.Environ()...)

	done := plumbCommand(cmd, channel, &errbuff)

	if err := cmd.Start(); err != nil {
		log.Warnf(c, "Failed git receive immediately: %s %s", err, errbuff.Bytes())
		return nil, err
	}
	fmt.Printf("Waiting for git-receive to run.\n")
	done.Wait()
	fmt.Printf("Waiting for deploy.\n")
	if err := cmd.Wait(); err != nil {
		log.Errf(c, "Error on command: %s %s", err, errbuff.Bytes())
		return nil, err
	}
	if errbuff.Len() > 0 {
		log.Warnf(c, "Unreported error: %s", errbuff.Bytes())
	}
	log.Infof(c, "Deploy complete.\n")

	return nil, nil
}

// Flush sends content to output.
//
// If no writer is specified, this will attempt to write to whatever is in the
// Context with the key "http.ResponseWriter". If no suitable writer is found, it will
// not write to anything at all.
//
// Params:
// 	- writer: A Writer of some sort. This will try to write to the HTTP response if no writer
// 	is specified.
// 	- content: The content to write as a body. If this is a byte[], it is sent unchanged. Otherwise.
// 	we first try to convert to a string, then pass it into a writer.
// 	- contentType: The content type header (e.g. text/html). Default is text/plain
// 	- responseCode: Integer HTTP Response Code: Default is `http.StatusOK`.
// 	- headers: a map[string]string of HTTP headers. The keys will be run through
// 	 http.CannonicalHeaderKey()
//
// Note that this is optimized for writing from strings or arrays, not Readers. For larger
// objects, you may find it more efficient to use a different command.
//
// Context:
// - If this finds `web.ContentEncoding`, it will set a content-encoding header.
//
// Returns
//
// 	- boolean true
func Flush(cxt cookoo.Context, params *cookoo.Params) (interface{}, cookoo.Interrupt) {

	// Make sure we have a place to write this stuff.
	writer, ok := params.Has("writer")
	if writer == nil {
		writer, ok = cxt.Has("http.ResponseWriter")
		if !ok {
			return false, nil
		}
	}
	out := writer.(http.ResponseWriter)

	// Get the rest of the info.
	code := params.Get("responseCode", http.StatusOK).(int)
	header := out.Header()
	contentType := params.Get("contentType", "text/plain; charset=utf-8").(string)

	// Prepare the content.
	var content []byte
	rawContent, ok := params.Has("content")
	if !ok {
		// No content. Send nothing in the body.
		content = []byte("")
	} else if byteContent, ok := rawContent.([]byte); ok {
		// Got a byte[]; add it as is.
		content = byteContent
	} else {
		// Use the formatter to convert to a string, and then
		// cast it to bytes.
		content = []byte(fmt.Sprintf("%v", rawContent))
	}

	// Add headers:
	header.Set(http.CanonicalHeaderKey("content-type"), contentType)

	te := cxt.Get(ContentEncoding, "").(string)
	if len(te) > 0 {
		header.Set(http.CanonicalHeaderKey("transfer-encoding"), te)
	}

	headerO, ok := params.Has("headers")
	if ok {
		headers := headerO.(map[string]string)
		for k, v := range headers {
			header.Add(http.CanonicalHeaderKey(k), v)
		}
	}

	// Send the headers.
	out.WriteHeader(code)

	//io.WriteString(out, content)
	out.Write(content)

	return true, nil
}

// DropToShell executes a glide plugin. A command that's implemented by
// another application is executed in a similar manner to the way git commands
// work. For example, 'glide foo' would try to execute the application glide-foo.
// Params:
//   - command: the name of the command to attempt executing.
func DropToShell(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
	args := c.Get("os.Args", nil).([]string)
	command := p.Get("command", "").(string)

	if len(args) == 0 {
		return nil, fmt.Errorf("Could not get os.Args.")
	}

	cwd, err := os.Getwd()
	if err != nil {
		return nil, err
	}

	projpath := cwd
	if tmp := os.Getenv("GLIDE_PROJECT"); len(tmp) != 0 {
		projpath = tmp
	}

	cmd := "glide-" + command
	var fullcmd string
	if fullcmd, err = exec.LookPath(cmd); err != nil {
		fullcmd = projpath + "/" + cmd
		if _, err := os.Stat(fullcmd); err != nil {
			return nil, fmt.Errorf("Command %s does not exist.", cmd)
		}
	}

	// Turning os.Args first argument from `glide` to `glide-command`
	args[0] = cmd
	// Removing the first argument (command)
	removed := false
	for i, v := range args {
		if removed == false && v == command {
			args = append(args[:i], args[i+1:]...)
			removed = true
		}
	}
	pa := os.ProcAttr{
		Files: []*os.File{os.Stdin, os.Stdout, os.Stderr},
		Dir:   cwd,
	}

	fmt.Printf("Delegating to plugin %s (%v)\n", fullcmd, args)

	proc, err := os.StartProcess(fullcmd, args, &pa)
	if err != nil {
		return nil, err
	}

	if _, err := proc.Wait(); err != nil {
		return nil, err
	}
	return nil, nil
}

// ServerInfo gets the server info for this request.
//
// This assumes that `http.Request` and `http.ResponseWriter` are in the context, which
// they are by default.
//
// Returns:
// 	- boolean true
func ServerInfo(cxt cookoo.Context, params *cookoo.Params) (interface{}, cookoo.Interrupt) {
	req := cxt.Get("http.Request", nil).(*http.Request)
	out := cxt.Get("http.ResponseWriter", nil).(http.ResponseWriter)

	out.Header().Add("X-Foo", "Bar")
	out.Header().Add("Content-type", "text/plain; charset=utf-8")

	fmt.Fprintf(out, "Request:\n %+v\n", req)
	fmt.Fprintf(out, "\n\n\nResponse:\n%+v\n", out)
	return true, nil
}

// ServeTLS does the same as Serve, but with SSL support.
//
// If `server.Address` is not found in the context, the default address is
// `:4433`.
//
// Neither certFile nor keyFile are stored in the context. These values are
// considered to be security sensitive.
func ServeTLS(reg *cookoo.Registry, router *cookoo.Router, cxt cookoo.Context, certFile, keyFile string) {
	addr := cxt.Get("server.Address", ":4433").(string)

	server := &http.Server{Addr: addr}
	server.Handler = NewCookooHandler(reg, router, cxt)

	go handleSignals(router, cxt, server)
	err := server.ListenAndServeTLS(certFile, keyFile)
	if err != nil {
		cxt.Logf("error", "Caught error while serving: %s", err)
		if router.HasRoute("@crash") {
			router.HandleRequest("@crash", cxt, false)
		}
	}
}

// Return the path to the vendor directory.
func VendorPath(c cookoo.Context) (string, error) {
	vendor := c.Get("VendorDir", "vendor").(string)
	filename := c.Get("yaml", "glide.yaml").(string)
	cwd, err := os.Getwd()
	if err != nil {
		return "", err
	}

	// Find the directory that contains glide.yaml
	yamldir, err := glideWD(cwd, filename)
	if err != nil {
		return cwd, err
	}

	gopath := filepath.Join(yamldir, vendor)

	return gopath, nil
}

// LinkPackage creates a symlink to the project within the GOPATH.
func LinkPackage(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
	cfg := c.Get("cfg", "").(*Config)
	pname := p.Get("path", cfg.Name).(string)

	//here, err := os.Getwd()
	//if err != nil {
	//	return nil, fmt.Errorf("Could not get current directory: %s", err)
	//}

	// Per issue #10, this may be nicer to work with in cases where repos are
	// moved.
	//here := "../.."
	depth := strings.Count(pname, "/")
	here := "../.." + strings.Repeat("/..", depth)

	gopath := os.Getenv("GOPATH")
	if len(gopath) == 0 {
		return nil, fmt.Errorf("$GOPATH appears to be unset")
	}
	if len(pname) == 0 {
		return nil, fmt.Errorf("glide.yaml is missing 'package:'")
	}

	base := path.Dir(pname)
	if base != "." {
		dir := fmt.Sprintf("%s/src/%s", gopath, base)
		if err := os.MkdirAll(dir, os.ModeDir|0755); err != nil {
			return nil, fmt.Errorf("Failed to make directory %s: %s", dir, err)
		}
	}

	ldest := fmt.Sprintf("%s/src/%s", gopath, pname)
	if err := os.Symlink(here, ldest); err != nil {
		if os.IsExist(err) {
			Info("Link to %s already exists. Skipping.\n", ldest)
		} else {
			return nil, fmt.Errorf("Failed to create symlink from %s to %s: %s", gopath, ldest, err)
		}
	}

	return ldest, nil
}