Issue #327 Creating Docker client from env settings

docker/daemon/client.go

@@ -0,0 +1,54 @@
+package daemon
+
+import (
+	"github.com/containers/image/types"
+	dockerclient "github.com/docker/docker/client"
+	"github.com/docker/go-connections/tlsconfig"
+	"net/http"
+	"path/filepath"
+)
+
+const (
+	// The default API version to be used in case none is explicitly specified
+	defaultAPIVersion = "1.22"
+)
+
+// NewDockerClient initializes a new API client based on the passed SystemContext.
+func newDockerClient(ctx *types.SystemContext) (*dockerclient.Client, error) {
+	httpClient, err := tlsConfig(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	host := dockerclient.DefaultDockerHost
+	if ctx != nil && ctx.DockerDaemonHost != "" {
+		host = ctx.DockerDaemonHost
+	}
+
+	return dockerclient.NewClient(host, defaultAPIVersion, httpClient, nil)
+}
+
+func tlsConfig(ctx *types.SystemContext) (*http.Client, error) {
+	options := tlsconfig.Options{}
+	if ctx != nil && ctx.DockerDaemonInsecureSkipTLSVerify {
+		options.InsecureSkipVerify = true
+	}
+
+	if ctx != nil && ctx.DockerDaemonCertPath != "" {
+		options.CAFile = filepath.Join(ctx.DockerDaemonCertPath, "ca.pem")
+		options.CertFile = filepath.Join(ctx.DockerDaemonCertPath, "cert.pem")
+		options.KeyFile = filepath.Join(ctx.DockerDaemonCertPath, "key.pem")
+	}
+
+	tlsc, err := tlsconfig.Client(options)
+	if err != nil {
+		return nil, err
+	}
+
+	return &http.Client{
+		Transport: &http.Transport{
+			TLSClientConfig: tlsc,
+		},
+		CheckRedirect: dockerclient.CheckRedirect,
+	}, nil
+}

docker/daemon/client_test.go

@@ -0,0 +1,93 @@
+package daemon
+
+import "testing"
+import (
+	"github.com/containers/image/types"
+	dockerclient "github.com/docker/docker/client"
+	"github.com/stretchr/testify/assert"
+	"net/http"
+	"os"
+	"path/filepath"
+)
+
+func TestDockerClientFromNilSystemContext(t *testing.T) {
+	client, err := newDockerClient(nil)
+
+	assert.Nil(t, err, "There should be no error creating the Docker client")
+	assert.NotNil(t, client, "A Docker client reference should have been returned")
+
+	assert.Equal(t, dockerclient.DefaultDockerHost, client.DaemonHost(), "The default docker host should have been used")
+	assert.Equal(t, defaultAPIVersion, client.ClientVersion(), "The default api version should have been used")
+}
+
+func TestDockerClientFromCertContext(t *testing.T) {
+	testDir := testDir(t)
+
+	host := "tcp://127.0.0.1:2376"
+	systemCtx := &types.SystemContext{
+		DockerDaemonCertPath:              filepath.Join(testDir, "testdata", "certs"),
+		DockerDaemonHost:                  host,
+		DockerDaemonInsecureSkipTLSVerify: true,
+	}
+
+	client, err := newDockerClient(systemCtx)
+
+	assert.Nil(t, err, "There should be no error creating the Docker client")
+	assert.NotNil(t, client, "A Docker client reference should have been returned")
+
+	assert.Equal(t, host, client.DaemonHost())
+	assert.Equal(t, "1.22", client.ClientVersion())
+}
+
+func TestTlsConfigFromInvalidCertPath(t *testing.T) {
+	ctx := &types.SystemContext{
+		DockerDaemonCertPath: "/foo/bar",
+	}
+
+	_, err := tlsConfig(ctx)
+
+	if assert.Error(t, err, "An error was expected") {
+		assert.Regexp(t, "could not read CA certificate", err.Error())
+	}
+}
+
+func TestTlsConfigFromCertPath(t *testing.T) {
+	testDir := testDir(t)
+
+	ctx := &types.SystemContext{
+		DockerDaemonCertPath:              filepath.Join(testDir, "testdata", "certs"),
+		DockerDaemonInsecureSkipTLSVerify: true,
+	}
+
+	httpClient, err := tlsConfig(ctx)
+
+	assert.NoError(t, err, "There should be no error creating the HTTP client")
+
+	tlsConfig := httpClient.Transport.(*http.Transport).TLSClientConfig
+	assert.True(t, tlsConfig.InsecureSkipVerify, "TLS verification should be skipped")
+	assert.Len(t, tlsConfig.Certificates, 1, "There should be one certificate")
+}
+
+func TestSkipTLSVerifyOnly(t *testing.T) {
+	//testDir := testDir(t)
+
+	ctx := &types.SystemContext{
+		DockerDaemonInsecureSkipTLSVerify: true,
+	}
+
+	httpClient, err := tlsConfig(ctx)
+
+	assert.NoError(t, err, "There should be no error creating the HTTP client")
+
+	tlsConfig := httpClient.Transport.(*http.Transport).TLSClientConfig
+	assert.True(t, tlsConfig.InsecureSkipVerify, "TLS verification should be skipped")
+	assert.Len(t, tlsConfig.Certificates, 0, "There should be no certificate")
+}
+
+func testDir(t *testing.T) string {
+	testDir, err := os.Getwd()
+	if err != nil {
+		t.Fatal("Unable to determine the current test directory")
+	}
+	return testDir
+}

docker/daemon/daemon_dest.go

@@ -24,7 +24,7 @@ type daemonImageDestination struct {
 }
 
 // newImageDestination returns a types.ImageDestination for the specified image reference.
-func newImageDestination(systemCtx *types.SystemContext, ref daemonReference) (types.ImageDestination, error) {
+func newImageDestination(ctx *types.SystemContext, ref daemonReference) (types.ImageDestination, error) {
 	if ref.ref == nil {
 		return nil, errors.Errorf("Invalid destination docker-daemon:%s: a destination must be a name:tag", ref.StringWithinTransport())
 	}
@@ -33,7 +33,7 @@ func newImageDestination(systemCtx *types.SystemContext, ref daemonReference) (t
 		return nil, errors.Errorf("Invalid destination docker-daemon:%s: a destination must be a name:tag", ref.StringWithinTransport())
 	}
 
-	c, err := client.NewClient(client.DefaultDockerHost, "1.22", nil, nil) // FIXME: overridable host
+	c, err := newDockerClient(ctx)
 	if err != nil {
 		return nil, errors.Wrap(err, "Error initializing docker engine client")
 	}
@@ -42,8 +42,8 @@ func newImageDestination(systemCtx *types.SystemContext, ref daemonReference) (t
 	// Commit() may never be called, so we may never read from this channel; so, make this buffered to allow imageLoadGoroutine to write status and terminate even if we never read it.
 	statusChannel := make(chan error, 1)
 
-	ctx, goroutineCancel := context.WithCancel(context.Background())
-	go imageLoadGoroutine(ctx, c, reader, statusChannel)
+	goroutineContext, goroutineCancel := context.WithCancel(context.Background())
+	go imageLoadGoroutine(goroutineContext, c, reader, statusChannel)
 
 	return &daemonImageDestination{
 		ref:             ref,

docker/daemon/daemon_src.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/containers/image/docker/tarfile"
 	"github.com/containers/image/types"
-	"github.com/docker/docker/client"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 )
@@ -35,7 +34,7 @@ type layerInfo struct {
 // is the config, and that the following len(RootFS) files are the layers, but that feels
 // way too brittle.)
 func newImageSource(ctx *types.SystemContext, ref daemonReference) (types.ImageSource, error) {
-	c, err := client.NewClient(client.DefaultDockerHost, "1.22", nil, nil) // FIXME: overridable host
+	c, err := newDockerClient(ctx)
 	if err != nil {
 		return nil, errors.Wrap(err, "Error initializing docker engine client")
 	}

docker/daemon/testdata/certs/ca.pem

@@ -0,0 +1,18 @@
+-----BEGIN CERTIFICATE-----
+MIICzjCCAbagAwIBAgIRAIGgYBNZse0EqRVzxe7aQGIwDQYJKoZIhvcNAQELBQAw
+EDEOMAwGA1UEChMFaGFyZHkwHhcNMTcxMDA0MDgzNDAwWhcNMjAwOTE4MDgzNDAw
+WjAQMQ4wDAYDVQQKEwVoYXJkeTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoC
+ggEBAMlrdtoXWlZMPFwgeKZHrGxjVe4KXkQy5MFBUfO48htyIe2OlZAd3HGyap41
+7L4YciFhw0bp7wHnYtSTiCHQrnA4SLzNuaU2NM5nJw+E4c5kNrkvhLJqpTNCaYCy
+Xbh3H8REW+5UJIgnyeKLx//kvlDm6p4O55+OLlGgzxNaTIgldKLPmx543VVt6VDT
+qgFlaYsRz8hZ12+qAqu5am/Wpfal2+Df7Pmmn5M90UBTUwY8CLc/ZiWbv6hihDWV
+I28JoM0onEqAx7phRd0SwwK4mYfEe/u614r3bZaI36e9ojU9/St4nbMoMeyZP96t
+DOdX9A1SMbsqLOYKXBKM+jXPEaECAwEAAaMjMCEwDgYDVR0PAQH/BAQDAgKsMA8G
+A1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQELBQADggEBALah7CjpwbEY6yjA2KDv
+VaAHEgz4Xd8USW/L2292EiQLmFdIaEJiiWRjtKFiF427TXfAPXvxHA2q9OElDW4d
+G6XAcBJg5mcBh8WRTHwfLQ8llfj7dH1/sfazSUZeat6lTIyhQfkF99LAJTqlfYAF
+aNqIQio7FAjGyJqIPYLa1FKmfLdZr9azb9IjTZLhBGBWdLF0+JOn+JBsl7g9BvUp
+ArCI0Wib/vsr368xkzWzKjij1exZdfw0TmsieNYvViFoFJGNCB5XLPo0bHrmMVVe
+25EGam+xPkG/JQP5Eb3iikSEn8y5SIeJ0nS0EQE6uXPv+lQj1LmVv8OYzjXqpoJT
+n6g=
+-----END CERTIFICATE-----

docker/daemon/testdata/certs/cert.pem

@@ -0,0 +1,18 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

docker/daemon/testdata/certs/key.pem

@@ -0,0 +1,27 @@
+-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----

types/types.go

@@ -285,7 +285,7 @@ type DockerAuthConfig struct {
 	Password string
 }
 
-// SystemContext allows parametrizing access to implicitly-accessed resources,
+// SystemContext allows parameterizing access to implicitly-accessed resources,
 // like configuration files in /etc and users' login state in their home directory.
 // Various components can share the same field only if their semantics is exactly
 // the same; if in doubt, add a new field.
@@ -324,8 +324,9 @@ type SystemContext struct {
 	DockerCertPath string
 	// If not "", overrides the system’s default path for a directory containing host[:port] subdirectories with the same structure as DockerCertPath above.
 	// Ignored if DockerCertPath is non-empty.
-	DockerPerHostCertDirPath    string
-	DockerInsecureSkipTLSVerify bool // Allow contacting docker registries over HTTP, or HTTPS with failed TLS verification. Note that this does not affect other TLS connections.
+	DockerPerHostCertDirPath string
+	// Allow contacting docker registries over HTTP, or HTTPS with failed TLS verification. Note that this does not affect other TLS connections.
+	DockerInsecureSkipTLSVerify bool
 	// if nil, the library tries to parse ~/.docker/config.json to retrieve credentials
 	DockerAuthConfig *DockerAuthConfig
 	// if not "", an User-Agent header is added to each request when contacting a registry.
@@ -336,6 +337,16 @@ type SystemContext struct {
 	DockerDisableV1Ping bool
 	// Directory to use for OSTree temporary files
 	OSTreeTmpDirPath string
+
+	// === docker/daemon.Transport overrides ===
+	// A directory containing a CA certificate (ending with ".crt"),
+	// a client certificate (ending with ".cert") and a client certificate key
+	// (ending with ".key") used when talking to a Docker daemon.
+	DockerDaemonCertPath string
+	// The hostname or IP to the Docker daemon. If not set (aka ""), client.DefaultDockerHost is assumed.
+	DockerDaemonHost string
+	// Used to skip TLS verification, off by default. To take effect DockerDaemonCertPath needs to be specified as well.
+	DockerDaemonInsecureSkipTLSVerify bool
 }
 
 // ProgressProperties is used to pass information from the copy code to a monitor which