package main import ( "bytes" "crypto/sha256" "encoding/hex" "fmt" "io" "log" "net/http" "net/url" "path" "path/filepath" "text/template" cfsslconfig "github.com/cloudflare/cfssl/config" restful "github.com/emicklei/go-restful" yaml "gopkg.in/yaml.v2" "novit.tech/direktil/pkg/config" "novit.tech/direktil/pkg/localconfig" bsconfig "novit.tech/direktil/pkg/bootstrapconfig" ) var cmdlineParam = restful.QueryParameter("cmdline", "Linux kernel cmdline addition") type renderContext struct { Host *localconfig.Host SSLConfig *cfsslconfig.Config // Linux kernel extra cmdline CmdLine string `yaml:"-"` } func renderCtx(w http.ResponseWriter, r *http.Request, ctx *renderContext, what string, create func(out io.Writer, ctx *renderContext) error) error { tag, err := ctx.Tag() if err != nil { return err } ctx.CmdLine = r.URL.Query().Get(cmdlineParam.Data().Name) if ctx.CmdLine != "" { what = what + "?cmdline=" + url.QueryEscape(ctx.CmdLine) } // get it or create it content, meta, err := casStore.GetOrCreate(tag, what, func(out io.Writer) error { log.Printf("building %s for %q", what, ctx.Host.Name) return create(out, ctx) }) if err != nil { return err } // serve it log.Printf("sending %s for %q", what, ctx.Host.Name) http.ServeContent(w, r, what, meta.ModTime(), content) return nil } func sslConfigFromLocalConfig(cfg *localconfig.Config) (sslCfg *cfsslconfig.Config, err error) { if len(cfg.SSLConfig) == 0 { sslCfg = &cfsslconfig.Config{} } else { sslCfg, err = cfsslconfig.LoadConfig([]byte(cfg.SSLConfig)) if err != nil { return } } return } func newRenderContext(host *localconfig.Host, cfg *localconfig.Config) (ctx *renderContext, err error) { sslCfg, err := sslConfigFromLocalConfig(cfg) if err != nil { return } return &renderContext{ Host: host, SSLConfig: sslCfg, }, nil } func (ctx *renderContext) Config() (ba []byte, cfg *config.Config, err error) { ba, err = ctx.render(ctx.Host.Config) if err != nil { return } cfg = &config.Config{} if err = yaml.Unmarshal(ba, cfg); err != nil { return } return } func (ctx *renderContext) BootstrapConfig() (ba []byte, cfg *bsconfig.Config, err error) { ba, err = ctx.render(ctx.Host.BootstrapConfig) if err != nil { return } cfg = &bsconfig.Config{} if err = yaml.Unmarshal(ba, cfg); err != nil { return } return } func (ctx *renderContext) render(templateText string) (ba []byte, err error) { tmpl, err := template.New(ctx.Host.Name + "/config"). Funcs(ctx.TemplateFuncs()). Parse(templateText) if err != nil { return } buf := bytes.NewBuffer(make([]byte, 0, 4096)) if err = tmpl.Execute(buf, nil); err != nil { return } ba = buf.Bytes() return } func (ctx *renderContext) distFilePath(path ...string) string { return filepath.Join(append([]string{*dataDir, "dist"}, path...)...) } func (ctx *renderContext) Tag() (string, error) { h := sha256.New() _, cfg, err := ctx.Config() if err != nil { return "", err } enc := yaml.NewEncoder(h) for _, o := range []interface{}{cfg, ctx} { if err := enc.Encode(o); err != nil { return "", err } } return hex.EncodeToString(h.Sum(nil)), nil } func asMap(v interface{}) map[string]interface{} { ba, err := yaml.Marshal(v) if err != nil { panic(err) // shouldn't happen } result := make(map[string]interface{}) if err := yaml.Unmarshal(ba, result); err != nil { panic(err) // shouldn't happen } return result } func (ctx *renderContext) TemplateFuncs() map[string]any { funcs := templateFuncs(ctx.SSLConfig) for name, method := range map[string]any{ "ssh_host_keys": func(dir, cluster, host string) (s string, err error) { if host == "" { host = ctx.Host.Name } if host != ctx.Host.Name { err = fmt.Errorf("wrong host name") return } pairs, err := getSSHKeyPairs(host) if err != nil { return } files := make([]config.FileDef, 0, len(pairs)*2) for _, pair := range pairs { basePath := path.Join(dir, "ssh_host_"+pair.Type+"_key") files = append(files, []config.FileDef{ { Path: basePath, Mode: 0600, Content: pair.Private, }, { Path: basePath + ".pub", Mode: 0644, Content: pair.Public, }, }...) } return asYaml(files) }, "host_download_token": func() (token string, err error) { key := ctx.Host.Name token, found, err := hostDownloadTokens.Get(key) if err != nil { return } if !found { token, err = newToken(32) if err != nil { return } err = hostDownloadTokens.Put(key, token) if err != nil { return } } return }, } { funcs[name] = method } return funcs }