airshipctl/pkg/container/api.go

/*
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

     https://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
*/

package container

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"os"
	"strings"

	// TODO this small library needs to be moved to airshipctl and extended
	// with splitting streams into Stderr and Stdout
	"github.com/ahmetb/dlog"
	"sigs.k8s.io/kustomize/kyaml/fn/runtime/runtimeutil"
	"sigs.k8s.io/kustomize/kyaml/kio"
	"sigs.k8s.io/kustomize/kyaml/runfn"
	kyaml "sigs.k8s.io/kustomize/kyaml/yaml"
	"sigs.k8s.io/yaml"

	"opendev.org/airship/airshipctl/pkg/api/v1alpha1"
	"opendev.org/airship/airshipctl/pkg/log"
)

// ClientV1Alpha1 provides airship generic container API
// TODO add generic mock for this client
type ClientV1Alpha1 interface {
	Run() error
}

// ClientV1Alpha1FactoryFunc used for tests
type ClientV1Alpha1FactoryFunc func(
	resultsDir string,
	input io.Reader,
	output io.Writer,
	conf *v1alpha1.GenericContainer) ClientV1Alpha1

type clientV1Alpha1 struct {
	resultsDir string
	input      io.Reader
	output     io.Writer
	conf       *v1alpha1.GenericContainer

	containerFunc containerFunc
}

type containerFunc func(ctx context.Context, driver string, url string) (Container, error)

// NewClientV1Alpha1 constructor for ClientV1Alpha1
func NewClientV1Alpha1(
	resultsDir string,
	input io.Reader,
	output io.Writer,
	conf *v1alpha1.GenericContainer) ClientV1Alpha1 {
	return &clientV1Alpha1{
		resultsDir:    resultsDir,
		output:        output,
		input:         input,
		conf:          conf,
		containerFunc: NewContainer,
	}
}

// Run will peform container run action based on the configuration
func (c *clientV1Alpha1) Run() error {
	// set default runtime
	switch c.conf.Spec.Type {
	case v1alpha1.GenericContainerTypeAirship, "":
		return c.runAirship()
	case v1alpha1.GenericContainerTypeKrm:
		return c.runKRM()
	default:
		return fmt.Errorf("uknown generic container type %s", c.conf.Spec.Type)
	}
}

func (c *clientV1Alpha1) runAirship() error {
	if c.conf.Spec.Airship.ContainerRuntime == "" {
		c.conf.Spec.Airship.ContainerRuntime = ContainerDriverDocker
	}

	var cont Container
	if c.containerFunc == nil {
		c.containerFunc = NewContainer
	}

	cont, err := c.containerFunc(
		context.Background(),
		c.conf.Spec.Airship.ContainerRuntime,
		c.conf.Spec.Image)
	if err != nil {
		return err
	}

	// this will split the env vars into the ones to be exported and the ones that have values
	contEnv := runtimeutil.NewContainerEnvFromStringSlice(c.conf.Spec.EnvVars)

	envs := []string{}
	for _, key := range contEnv.VarsToExport {
		envs = append(envs, strings.Join([]string{key, os.Getenv(key)}, "="))
	}

	for key, value := range contEnv.EnvVars {
		envs = append(envs, strings.Join([]string{key, value}, "="))
	}

	node, err := kyaml.Parse(c.conf.Config)
	if err != nil {
		return err
	}

	decoratedInput := bytes.NewBuffer([]byte{})
	pipeline := &kio.Pipeline{
		Inputs: []kio.Reader{&kio.ByteReader{Reader: c.input}},
		Outputs: []kio.Writer{kio.ByteWriter{
			Writer:                decoratedInput,
			KeepReaderAnnotations: true,
			WrappingKind:          kio.ResourceListKind,
			WrappingAPIVersion:    kio.ResourceListAPIVersion,
			FunctionConfig:        node,
		}},
	}

	err = pipeline.Execute()
	if err != nil {
		return err
	}

	log.Printf("Starting container with image: '%s', cmd: '%s'",
		c.conf.Spec.Image,
		c.conf.Spec.Airship.Cmd)
	err = cont.RunCommand(RunCommandOptions{
		Privileged: c.conf.Spec.Airship.Privileged,
		Cmd:        c.conf.Spec.Airship.Cmd,
		Mounts:     convertDockerMount(c.conf.Spec.StorageMounts),
		EnvVars:    envs,
		Input:      decoratedInput,
	})
	if err != nil {
		return err
	}

	log.Debugf("Waiting for container run to finish, image: '%s', cmd: '%s'",
		c.conf.Spec.Image,
		c.conf.Spec.Airship.Cmd)

	err = cont.WaitUntilFinished()
	if err != nil {
		return err
	}

	rOut, err := cont.GetContainerLogs(GetLogOptions{Stdout: true})
	if err != nil {
		return err
	}
	defer rOut.Close()

	rErr, err := cont.GetContainerLogs(GetLogOptions{Stderr: true})
	if err != nil {
		return err
	}
	defer rOut.Close()

	parsedOut := dlog.NewReader(rOut)
	parsedErr := dlog.NewReader(rErr)

	// write container stderr to airship log output
	_, err = io.Copy(log.Writer(), parsedErr)
	if err != nil {
		return err
	}
	return writeSink(c.resultsDir, parsedOut, c.output)
}

func (c *clientV1Alpha1) runKRM() error {
	mounts := convertKRMMount(c.conf.Spec.StorageMounts)
	fns := &runfn.RunFns{
		Network:               c.conf.Spec.HostNetwork,
		AsCurrentUser:         true,
		Path:                  c.resultsDir,
		Input:                 c.input,
		Output:                c.output,
		StorageMounts:         mounts,
		ContinueOnEmptyResult: true,
	}
	function, err := kyaml.Parse(c.conf.Config)
	if err != nil {
		return err
	}
	// Transform GenericContainer.Spec to annotation,
	// because we need to specify runFns config in annotation
	spec, err := yaml.Marshal(runtimeutil.FunctionSpec{
		Container: runtimeutil.ContainerSpec{
			Image:         c.conf.Spec.Image,
			Network:       c.conf.Spec.HostNetwork,
			Env:           c.conf.Spec.EnvVars,
			StorageMounts: mounts,
		},
	})
	if err != nil {
		return err
	}
	annotation := kyaml.SetAnnotation(runtimeutil.FunctionAnnotationKey, string(spec))
	_, err = annotation.Filter(function)
	if err != nil {
		return err
	}

	fns.Functions = []*kyaml.RNode{function}

	return fns.Execute()
}

// writeSink output to directory on filesystem sink
func writeSink(path string, rc io.Reader, out io.Writer) error {
	inputs := []kio.Reader{&kio.ByteReader{Reader: rc}}
	var outputs []kio.Writer
	switch {
	case out == nil && path != "":
		log.Debugf("writing container output to files in directory %s", path)
		outputs = []kio.Writer{&kio.LocalPackageWriter{PackagePath: path}}
	case out != nil:
		log.Debugf("writing container output to provided writer")
		outputs = []kio.Writer{&kio.ByteWriter{Writer: out}}
	default:
		log.Debugf("writing container output to stdout")
		outputs = []kio.Writer{&kio.ByteWriter{Writer: os.Stdout}}
	}
	return kio.Pipeline{Inputs: inputs, Outputs: outputs}.Execute()
}

func convertKRMMount(airMounts []v1alpha1.StorageMount) (fnsMounts []runtimeutil.StorageMount) {
	for _, mount := range airMounts {
		fnsMounts = append(fnsMounts, runtimeutil.StorageMount{
			MountType:     mount.MountType,
			Src:           mount.Src,
			DstPath:       mount.DstPath,
			ReadWriteMode: mount.ReadWriteMode,
		})
	}
	return fnsMounts
}

func convertDockerMount(airMounts []v1alpha1.StorageMount) (mounts []Mount) {
	for _, mount := range airMounts {
		mnt := Mount{
			Type: mount.MountType,
			Src:  mount.Src,
			Dst:  mount.DstPath,
		}
		if !mount.ReadWriteMode {
			mnt.ReadOnly = true
		}
		mounts = append(mounts, mnt)
	}
	return mounts
}