package libkpod import ( "encoding/json" "io/ioutil" "os" "path/filepath" "regexp" "strings" "syscall" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) const ( // DefaultHooksDirPath Default directory containing hooks config files DefaultHooksDirPath = "/usr/share/containers/oci/hooks.d" // OverrideHooksDirPath Directory where admin can override the default configuration OverrideHooksDirPath = "/etc/containers/oci/hooks.d" ) // HookParams is the structure returned from read the hooks configuration type HookParams struct { Hook string `json:"hook"` Stage []string `json:"stage"` Cmds []string `json:"cmd"` Annotations []string `json:"annotation"` HasBindMounts bool `json:"hasbindmounts"` } // readHook reads hooks json files, verifies it and returns the json config func readHook(hookPath string) (HookParams, error) { var hook HookParams raw, err := ioutil.ReadFile(hookPath) if err != nil { return hook, errors.Wrapf(err, "error Reading hook %q", hookPath) } if err := json.Unmarshal(raw, &hook); err != nil { return hook, errors.Wrapf(err, "error Unmarshalling JSON for %q", hookPath) } if _, err := os.Stat(hook.Hook); err != nil { return hook, errors.Wrapf(err, "unable to stat hook %q in hook config %q", hook.Hook, hookPath) } validStage := map[string]bool{"prestart": true, "poststart": true, "poststop": true} for _, cmd := range hook.Cmds { if _, err = regexp.Compile(cmd); err != nil { return hook, errors.Wrapf(err, "invalid cmd regular expression %q defined in hook config %q", cmd, hookPath) } } for _, cmd := range hook.Annotations { if _, err = regexp.Compile(cmd); err != nil { return hook, errors.Wrapf(err, "invalid cmd regular expression %q defined in hook config %q", cmd, hookPath) } } for _, stage := range hook.Stage { if !validStage[stage] { return hook, errors.Wrapf(err, "unknown stage %q defined in hook config %q", stage, hookPath) } } return hook, nil } // readHooks reads hooks json files in directory to setup OCI Hooks // adding hooks to the passedin hooks map. func readHooks(hooksPath string, hooks map[string]HookParams) error { if _, err := os.Stat(hooksPath); err != nil { if os.IsNotExist(err) { logrus.Warnf("hooks path: %q does not exist", hooksPath) return nil } return errors.Wrapf(err, "unable to stat hooks path %q", hooksPath) } files, err := ioutil.ReadDir(hooksPath) if err != nil { return err } for _, file := range files { if !strings.HasSuffix(file.Name(), ".json") { continue } hook, err := readHook(filepath.Join(hooksPath, file.Name())) if err != nil { return err } for key, h := range hooks { // hook.Hook can only be defined in one hook file, unless it has the // same name in the override path. if hook.Hook == h.Hook && key != file.Name() { return errors.Wrapf(syscall.EINVAL, "duplicate path, hook %q from %q already defined in %q", hook.Hook, hooksPath, key) } } hooks[file.Name()] = hook } return nil }