Add hooks support to podman

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

Closes: #155
Approved by: mheon

cmd/podman/main.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/containers/storage/pkg/reexec"
 	"github.com/pkg/errors"
+	"github.com/projectatomic/libpod/pkg/hooks"
 	"github.com/projectatomic/libpod/version"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
@@ -122,6 +123,12 @@ func main() {
 			Name:  "cpu-profile",
 			Usage: "path for the cpu profiling results",
 		},
+		cli.StringFlag{
+			Name:   "hooks-dir-path",
+			Usage:  "set the OCI hooks directory path",
+			Value:  hooks.DefaultHooksDir,
+			Hidden: true,
+		},
 		cli.StringFlag{
 			Name:  "log-level",
 			Usage: "log messages above specified level: debug, info, warn, error (default), fatal or panic",

cmd/podman/spec.go

@@ -378,7 +378,6 @@ func createConfigToOCISpec(config *createConfig) (*spec.Spec, error) {
 	}
 
 	/*
-			Hooks: &configSpec.Hooks{},
 			//Annotations
 				Resources: &configSpec.LinuxResources{
 					BlockIO: &blkio,

cmd/podman/utils.go

@@ -48,6 +48,7 @@ func getRuntime(c *cli.Context) (*libpod.Runtime, error) {
 	if c.GlobalIsSet("cni-config-dir") {
 		options = append(options, libpod.WithCNIConfigDir(c.GlobalString("cni-config-dir")))
 	}
+	options = append(options, libpod.WithHooksDir(c.GlobalString("hooks-dir-path")))
 
 	// TODO flag to set CNI plugins dir?
 

libpod/container_internal.go

@@ -7,6 +7,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"syscall"
 	"time"
@@ -22,6 +23,7 @@ import (
 	"github.com/pkg/errors"
 	crioAnnotations "github.com/projectatomic/libpod/pkg/annotations"
 	"github.com/projectatomic/libpod/pkg/chrootuser"
+	"github.com/projectatomic/libpod/pkg/hooks"
 	"github.com/projectatomic/libpod/pkg/secrets"
 	"github.com/projectatomic/libpod/pkg/util"
 	"github.com/sirupsen/logrus"
@@ -931,6 +933,9 @@ func (c *Container) generateSpec() (*spec.Spec, error) {
 		}
 	}
 
+	if err := c.setupOCIHooks(&g); err != nil {
+		return nil, errors.Wrapf(err, "error setting up OCI Hooks")
+	}
 	// Bind builtin image volumes
 	if c.config.ImageVolumes {
 		if err := c.addImageVolumes(&g); err != nil {
@@ -1103,3 +1108,58 @@ func (c *Container) saveSpec(spec *spec.Spec) error {
 
 	return nil
 }
+
+func (c *Container) setupOCIHooks(g *generate.Generator) error {
+	addedHooks := map[string]struct{}{}
+	ocihooks, err := hooks.SetupHooks(c.runtime.config.HooksDir)
+	if err != nil {
+		return err
+	}
+	addHook := func(hook hooks.HookParams) error {
+		// Only add a hook once
+		if _, ok := addedHooks[hook.Hook]; !ok {
+			if err := hooks.AddOCIHook(g, hook); err != nil {
+				return err
+			}
+			addedHooks[hook.Hook] = struct{}{}
+		}
+		return nil
+	}
+	for _, hook := range ocihooks {
+		logrus.Debugf("SetupOCIHooks", hook)
+		if hook.HasBindMounts && len(c.config.Spec.Mounts) > 0 {
+			if err := addHook(hook); err != nil {
+				return err
+			}
+			continue
+		}
+		for _, cmd := range hook.Cmds {
+			match, err := regexp.MatchString(cmd, c.config.Spec.Process.Args[0])
+			if err != nil {
+				logrus.Errorf("Invalid regex %q:%q", cmd, err)
+				continue
+			}
+			if match {
+				if err := addHook(hook); err != nil {
+					return err
+				}
+			}
+		}
+		annotations := c.Spec().Annotations
+		for _, annotationRegex := range hook.Annotations {
+			for _, annotation := range annotations {
+				match, err := regexp.MatchString(annotationRegex, annotation)
+				if err != nil {
+					logrus.Errorf("Invalid regex %q:%q", annotationRegex, err)
+					continue
+				}
+				if match {
+					if err := addHook(hook); err != nil {
+						return err
+					}
+				}
+			}
+		}
+	}
+	return nil
+}

libpod/options.go

@@ -172,6 +172,20 @@ func WithStaticDir(dir string) RuntimeOption {
 	}
 }
 
+// WithHooksDir sets the directory to look for OCI runtime hooks config
+// Note we are not saving this in database, since this is really just for used
+// for testing
+func WithHooksDir(hooksDir string) RuntimeOption {
+	return func(rt *Runtime) error {
+		if rt.valid {
+			return ErrRuntimeFinalized
+		}
+
+		rt.config.HooksDir = hooksDir
+		return nil
+	}
+}
+
 // WithTmpDir sets the directory that temporary runtime files which are not
 // expected to survive across reboots will be stored
 // This should be located on a tmpfs mount (/tmp or /var/run for example)

libpod/runtime.go

@@ -15,6 +15,7 @@ import (
 	"github.com/docker/docker/pkg/namesgenerator"
 	"github.com/pkg/errors"
 	"github.com/projectatomic/libpod/libpod/image"
+	"github.com/projectatomic/libpod/pkg/hooks"
 	"github.com/sirupsen/logrus"
 	"github.com/ulule/deepcopier"
 )
@@ -127,6 +128,8 @@ type RuntimeConfig struct {
 	// CNIPluginDir sets a number of directories where the CNI network
 	// plugins can be located
 	CNIPluginDir []string `toml:"cni_plugin_dir"`
+	// HooksDir Path to the directory containing hooks configuration files
+	HooksDir string `toml:"hooks_dir"`
 }
 
 var (
@@ -153,6 +156,7 @@ var (
 			"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
 		},
 		CgroupManager: "cgroupfs",
+		HooksDir:      hooks.DefaultHooksDir,
 		StaticDir:     filepath.Join(storage.DefaultStoreOptions.GraphRoot, "libpod"),
 		TmpDir:        "/var/run/libpod",
 		MaxLogSize:    -1,

libpod/testdata/config.toml

@@ -0,0 +1,28 @@
+[crio]
+  root = "/var/lib/containers/storage"
+  runroot = "/var/run/containers/storage"
+  storage_driver = "overlay2"
+  log_dir = "/var/log/crio/pods"
+  file_locking = true
+  [crio.runtime]
+    runtime = "/usr/bin/runc"
+    runtime_untrusted_workload = ""
+    default_workload_trust = "trusted"
+    conmon = "/usr/local/libexec/crio/conmon"
+    conmon_env = ["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"]
+    selinux = true
+    seccomp_profile = "/etc/crio/seccomp.json"
+    apparmor_profile = "crio-default"
+    cgroup_manager = "cgroupfs"
+    hooks_dir_path = "/usr/share/containers/oci/hooks.d"
+    pids_limit = 2048
+    container_exits_dir = "/var/run/podman/exits"
+  [crio.image]
+    default_transport = "docker://"
+    pause_image = "kubernetes/pause"
+    pause_command = "/pause"
+    signature_policy = ""
+    image_volumes = "mkdir"
+  [crio.network]
+    network_dir = "/etc/cni/net.d/"
+    plugin_dir = "/opt/cni/bin/"

pkg/hooks/hooks.go

@@ -0,0 +1,141 @@
+package hooks
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"syscall"
+
+	spec "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/opencontainers/runtime-tools/generate"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	// DefaultHooksDir Default directory containing hooks config files
+	DefaultHooksDir = "/usr/share/containers/oci/hooks.d"
+	// OverrideHooksDir Directory where admin can override the default configuration
+	OverrideHooksDir = "/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"`
+	Arguments     []string `json:"arguments"`
+}
+
+// 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
+}
+
+// SetupHooks takes a hookspath and reads all of the hooks in that directory.
+// returning a map of the configured hooks
+func SetupHooks(hooksPath string) (map[string]HookParams, error) {
+	hooksMap := make(map[string]HookParams)
+	if err := readHooks(hooksPath, hooksMap); err != nil {
+		return nil, err
+	}
+	if hooksPath == DefaultHooksDir {
+		if err := readHooks(OverrideHooksDir, hooksMap); err != nil {
+			return nil, err
+		}
+	}
+
+	return hooksMap, nil
+}
+
+// AddOCIHook generates OCI specification using the included hook
+func AddOCIHook(g *generate.Generator, hook HookParams) error {
+	for _, stage := range hook.Stage {
+		h := spec.Hook{
+			Path: hook.Hook,
+			Args: append([]string{hook.Hook}, hook.Arguments...),
+			Env:  []string{fmt.Sprintf("stage=%s", stage)},
+		}
+		logrus.Debugf("AddOCIHook", h)
+		switch stage {
+		case "prestart":
+			g.AddPreStartHook(h)
+
+		case "poststart":
+			g.AddPostStartHook(h)
+
+		case "poststop":
+			g.AddPostStopHook(h)
+		}
+	}
+	return nil
+}

test/e2e/hooks/checkhook.json

@@ -1,5 +1,5 @@
 {
     "cmd" : [".*"],
-    "hook" : "HOOKSDIR/checkhook.sh",
+    "hook" : "/tmp/checkhook.sh",
     "stage" : [ "prestart" ]
 }

test/e2e/libpod_suite_test.go

@@ -156,6 +156,9 @@ func (p *PodmanTest) MakeOptions() []string {
 // Podman is the exec call to podman on the filesystem
 func (p *PodmanTest) Podman(args []string) *PodmanSession {
 	podmanOptions := p.MakeOptions()
+	if os.Getenv("HOOK_OPTION") != "" {
+		podmanOptions = append(podmanOptions, os.Getenv("HOOK_OPTION"))
+	}
 	podmanOptions = append(podmanOptions, strings.Split(p.StorageOptions, " ")...)
 	podmanOptions = append(podmanOptions, args...)
 	fmt.Printf("Running: %s %s\n", p.PodmanBinary, strings.Join(podmanOptions, " "))

test/e2e/run_test.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/mrunalp/fileutils"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 )
@@ -217,6 +218,19 @@ var _ = Describe("Podman run", func() {
 		Expect(session.ExitCode()).To(Equal(0))
 	})
 
+	It("podman test hooks", func() {
+		hcheck := "/run/hookscheck"
+		hooksDir := "/tmp/hooks"
+		os.Mkdir(hooksDir, 0755)
+		fileutils.CopyFile("hooks/hooks.json", hooksDir)
+		os.Setenv("HOOK_OPTION", fmt.Sprintf("--hooks-dir-path=%s", hooksDir))
+		os.Remove(hcheck)
+		session := podmanTest.Podman([]string{"run", ALPINE, "ls"})
+		session.Wait(10)
+		os.Unsetenv("HOOK_OPTION")
+		Expect(session.ExitCode()).To(Equal(0))
+	})
+
 	It("podman run with secrets", func() {
 		containersDir := "/usr/share/containers"
 		err := os.MkdirAll(containersDir, 0755)

vendor.conf

@@ -86,3 +86,4 @@ k8s.io/apiserver 4d1163080139f1f9094baf8a3a6099e85e1867f6 https://github.com/kub
 k8s.io/client-go 7cd1d3291b7d9b1e2d54d4b69eb65995eaf8888e https://github.com/kubernetes/client-go
 k8s.io/kube-openapi 275e2ce91dec4c05a4094a7b1daee5560b555ac9 https://github.com/kubernetes/kube-openapi
 k8s.io/utils 258e2a2fa64568210fbd6267cf1d8fd87c3cb86e https://github.com/kubernetes/utils
+github.com/mrunalp/fileutils master

vendor/github.com/mrunalp/fileutils/LICENSE

@@ -0,0 +1,191 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
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+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
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+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
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+      "Object" form shall mean any form resulting from mechanical
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vendor/github.com/mrunalp/fileutils/README.md

@@ -0,0 +1,5 @@
+# fileutils
+
+Collection of utilities for file manipulation in golang
+
+The library is based on docker pkg/archive pkg/idtools but does copies instead of handling archive formats.

vendor/github.com/mrunalp/fileutils/fileutils.go

@@ -0,0 +1,158 @@
+package fileutils
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"syscall"
+)
+
+// CopyFile copies the file at source to dest
+func CopyFile(source string, dest string) error {
+	si, err := os.Lstat(source)
+	if err != nil {
+		return err
+	}
+
+	st, ok := si.Sys().(*syscall.Stat_t)
+	if !ok {
+		return fmt.Errorf("could not convert to syscall.Stat_t")
+	}
+
+	uid := int(st.Uid)
+	gid := int(st.Gid)
+
+	// Handle symlinks
+	if si.Mode()&os.ModeSymlink != 0 {
+		target, err := os.Readlink(source)
+		if err != nil {
+			return err
+		}
+		if err := os.Symlink(target, dest); err != nil {
+			return err
+		}
+	}
+
+	// Handle device files
+	if st.Mode&syscall.S_IFMT == syscall.S_IFBLK || st.Mode&syscall.S_IFMT == syscall.S_IFCHR {
+		devMajor := int64(major(uint64(st.Rdev)))
+		devMinor := int64(minor(uint64(st.Rdev)))
+		mode := uint32(si.Mode() & 07777)
+		if st.Mode&syscall.S_IFMT == syscall.S_IFBLK {
+			mode |= syscall.S_IFBLK
+		}
+		if st.Mode&syscall.S_IFMT == syscall.S_IFCHR {
+			mode |= syscall.S_IFCHR
+		}
+		if err := syscall.Mknod(dest, mode, int(mkdev(devMajor, devMinor))); err != nil {
+			return err
+		}
+	}
+
+	// Handle regular files
+	if si.Mode().IsRegular() {
+		sf, err := os.Open(source)
+		if err != nil {
+			return err
+		}
+		defer sf.Close()
+
+		df, err := os.Create(dest)
+		if err != nil {
+			return err
+		}
+		defer df.Close()
+
+		_, err = io.Copy(df, sf)
+		if err != nil {
+			return err
+		}
+	}
+
+	// Chown the file
+	if err := os.Lchown(dest, uid, gid); err != nil {
+		return err
+	}
+
+	// Chmod the file
+	if !(si.Mode()&os.ModeSymlink == os.ModeSymlink) {
+		if err := os.Chmod(dest, si.Mode()); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// CopyDirectory copies the files under the source directory
+// to dest directory. The dest directory is created if it
+// does not exist.
+func CopyDirectory(source string, dest string) error {
+	fi, err := os.Stat(source)
+	if err != nil {
+		return err
+	}
+
+	// Get owner.
+	st, ok := fi.Sys().(*syscall.Stat_t)
+	if !ok {
+		return fmt.Errorf("could not convert to syscall.Stat_t")
+	}
+
+	// We have to pick an owner here anyway.
+	if err := MkdirAllNewAs(dest, fi.Mode(), int(st.Uid), int(st.Gid)); err != nil {
+		return err
+	}
+
+	return filepath.Walk(source, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Get the relative path
+		relPath, err := filepath.Rel(source, path)
+		if err != nil {
+			return nil
+		}
+
+		if info.IsDir() {
+			// Skip the source directory.
+			if path != source {
+				// Get the owner.
+				st, ok := info.Sys().(*syscall.Stat_t)
+				if !ok {
+					return fmt.Errorf("could not convert to syscall.Stat_t")
+				}
+
+				uid := int(st.Uid)
+				gid := int(st.Gid)
+
+				if err := os.Mkdir(filepath.Join(dest, relPath), info.Mode()); err != nil {
+					return err
+				}
+
+				if err := os.Lchown(filepath.Join(dest, relPath), uid, gid); err != nil {
+					return err
+				}
+			}
+			return nil
+		}
+
+		return CopyFile(path, filepath.Join(dest, relPath))
+	})
+}
+
+// Gives a number indicating the device driver to be used to access the passed device
+func major(device uint64) uint64 {
+	return (device >> 8) & 0xfff
+}
+
+// Gives a number that serves as a flag to the device driver for the passed device
+func minor(device uint64) uint64 {
+	return (device & 0xff) | ((device >> 12) & 0xfff00)
+}
+
+func mkdev(major int64, minor int64) uint32 {
+	return uint32(((minor & 0xfff00) << 12) | ((major & 0xfff) << 8) | (minor & 0xff))
+}

vendor/github.com/mrunalp/fileutils/idtools.go

@@ -0,0 +1,49 @@
+package fileutils
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// MkdirAllNewAs creates a directory (include any along the path) and then modifies
+// ownership ONLY of newly created directories to the requested uid/gid. If the
+// directories along the path exist, no change of ownership will be performed
+func MkdirAllNewAs(path string, mode os.FileMode, ownerUID, ownerGID int) error {
+	// make an array containing the original path asked for, plus (for mkAll == true)
+	// all path components leading up to the complete path that don't exist before we MkdirAll
+	// so that we can chown all of them properly at the end.  If chownExisting is false, we won't
+	// chown the full directory path if it exists
+	var paths []string
+	if _, err := os.Stat(path); err != nil && os.IsNotExist(err) {
+		paths = []string{path}
+	} else if err == nil {
+		// nothing to do; directory path fully exists already
+		return nil
+	}
+
+	// walk back to "/" looking for directories which do not exist
+	// and add them to the paths array for chown after creation
+	dirPath := path
+	for {
+		dirPath = filepath.Dir(dirPath)
+		if dirPath == "/" {
+			break
+		}
+		if _, err := os.Stat(dirPath); err != nil && os.IsNotExist(err) {
+			paths = append(paths, dirPath)
+		}
+	}
+
+	if err := os.MkdirAll(path, mode); err != nil && !os.IsExist(err) {
+		return err
+	}
+
+	// even if it existed, we will chown the requested path + any subpaths that
+	// didn't exist when we called MkdirAll
+	for _, pathComponent := range paths {
+		if err := os.Chown(pathComponent, ownerUID, ownerGID); err != nil {
+			return err
+		}
+	}
+	return nil
+}