github.com/wmuizelaar/kpt@v0.0.0-20221018115725-bd564717b2ed/commands/fn/doc/cmdfndoc.go (about)

     1  // Copyright 2019 Google LLC
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package doc
    16  
    17  import (
    18  	"bytes"
    19  	"context"
    20  	"errors"
    21  	"fmt"
    22  	"os"
    23  	"os/exec"
    24  
    25  	"github.com/GoogleContainerTools/kpt/internal/docs/generated/fndocs"
    26  	"github.com/GoogleContainerTools/kpt/internal/fnruntime"
    27  	"github.com/GoogleContainerTools/kpt/internal/printer"
    28  	"github.com/GoogleContainerTools/kpt/internal/util/cmdutil"
    29  	"github.com/spf13/cobra"
    30  )
    31  
    32  func NewRunner(ctx context.Context, parent string) *Runner {
    33  	r := &Runner{
    34  		Ctx: ctx,
    35  	}
    36  	c := &cobra.Command{
    37  		Use:     "doc --image=IMAGE",
    38  		Args:    cobra.MaximumNArgs(0),
    39  		Short:   fndocs.DocShort,
    40  		Long:    fndocs.DocShort + "\n" + fndocs.DocLong,
    41  		Example: fndocs.DocExamples,
    42  		RunE:    r.runE,
    43  	}
    44  	r.Command = c
    45  	c.Flags().StringVarP(&r.Image, "image", "i", "", "kpt function image name")
    46  	_ = r.Command.RegisterFlagCompletionFunc("image", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
    47  		return cmdutil.SuggestFunctions(cmd), cobra.ShellCompDirectiveDefault
    48  	})
    49  	cmdutil.FixDocs("kpt", parent, c)
    50  	return r
    51  }
    52  
    53  func NewCommand(ctx context.Context, parent string) *cobra.Command {
    54  	return NewRunner(ctx, parent).Command
    55  }
    56  
    57  type Runner struct {
    58  	Image   string
    59  	Command *cobra.Command
    60  	Ctx     context.Context
    61  }
    62  
    63  func (r *Runner) runE(c *cobra.Command, _ []string) error {
    64  	if r.Image == "" {
    65  		return errors.New("image must be specified")
    66  	}
    67  	// TODO: We probably should be going through the runner
    68  	image, err := fnruntime.ResolveToImageForCLI(c.Context(), r.Image)
    69  	if err != nil {
    70  		return err
    71  	}
    72  	var out, errout bytes.Buffer
    73  	dockerRunArgs := []string{
    74  		"run",
    75  		"--rm", // delete the container afterward
    76  		image,
    77  		"--help",
    78  	}
    79  	// If the env var is empty, stringToContainerRuntime defaults it to docker.
    80  	runtime, err := fnruntime.StringToContainerRuntime(os.Getenv(fnruntime.ContainerRuntimeEnv))
    81  	if err != nil {
    82  		return err
    83  	}
    84  
    85  	err = fnruntime.ContainerRuntimeAvailable(runtime)
    86  	if err != nil {
    87  		return err
    88  	}
    89  
    90  	cmd := exec.Command(runtime.GetBin(), dockerRunArgs...)
    91  	cmd.Stdout = &out
    92  	cmd.Stderr = &errout
    93  	err = cmd.Run()
    94  	pr := printer.FromContextOrDie(r.Ctx)
    95  	if err != nil {
    96  		pr.Printf(errout.String())
    97  		return fmt.Errorf("please ensure the container has an entrypoint and it supports --help flag: %w", err)
    98  	}
    99  	fmt.Fprintln(pr.OutStream(), out.String())
   100  	return nil
   101  }