image_pull.go

// Copyright 2024 Harald Albrecht.
//
// 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
//
//    http://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 morbyd

import (
	"context"
	"fmt"
	"io"

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/pkg/jsonmessage"
)

type PullImageOpt func(*pullImageOptions)

type pullImageOptions struct {
	types.ImagePullOptions
	out io.Writer
}

// PullImage pulls a container image specified by the image reference, if not
// already locally available. The additional pull options are applied in the
// order they are provided.
//
// If no pull process output writer has been specified using
// [WithPullImageOutput] any output (such as pull progress, et cetera) will
// simply be discarded.
//
// Any pull process errors will be reported.
func (s *Session) PullImage(ctx context.Context, imgref string, opts ...PullImageOpt) error {
	pios := pullImageOptions{}
	for _, opt := range opts {
		opt(&pios)
	}
	if pios.out == nil {
		pios.out = io.Discard
	}
	r, err := s.moby.ImagePull(ctx, imgref, pios.ImagePullOptions)
	if err != nil {
		return fmt.Errorf("image pull failed, reason: %w", err)
	}
	defer r.Close()
	err = jsonmessage.DisplayJSONMessagesStream(r, pios.out, 0, false, nil)
	return err
}

// WithImageBuildOutput set the writer to send the output of the image pull
// process to.
func WithPullImageOutput(w io.Writer) PullImageOpt {
	return func(pios *pullImageOptions) {
		pios.out = w
	}
}