engine/dockerclient: fixup error messages format

agent/engine/dockerclient/dockerclientfactory.go

@@ -22,12 +22,10 @@ import (
 )
 
 const (
-	// minDockerAPILinux is the min Docker API version supported by agent
-	minDockerAPILinux = Version_1_17
 	// minAPIVersionKey is the docker.Env key for min API version
-	minAPIVersionKey  = "MinAPIVersion"
+	minAPIVersionKey = "MinAPIVersion"
 	// apiVersionKey is the docker.Env key for API version
-	apiVersionKey	  = "ApiVersion"
+	apiVersionKey    = "ApiVersion"
 )
 // Factory provides a collection of docker remote clients that include a
 // recommended client version as well as a set of alternative supported
@@ -122,7 +120,7 @@ func findDockerVersions(endpoint string) map[DockerVersion]dockeriface.Client {
 	// Docker versions
 	clients, err := findDockerVersionsfromMinMaxVersions(endpoint)
 	if err != nil {
-		log.Infof("Error getting Docker clients from min API version: %v", err)
+		log.Debugf("Unable to get Docker clients from min API version: %v", err)
 	} else {
 		return clients
 	}
@@ -146,14 +144,14 @@ func findDockerVersions(endpoint string) map[DockerVersion]dockeriface.Client {
 
 func findDockerVersionsfromMinMaxVersions(endpoint string) (map[DockerVersion]dockeriface.Client, error) {
 	// get a Docker client with the default supported version
-	client, err := newVersionedClient(endpoint, string(minDockerAPILinux))
+	client, err := newVersionedClient(endpoint, string(minDockerAPIVersion))
 	if err != nil {
-		return nil, errors.Wrap(err, "Error while creating client")
+		return nil, errors.Wrap(err, "min api version check: error while creating default Docker client")
 	}
 
 	clientVersion, err := client.Version()
 	if err != nil {
-		return nil, errors.Wrap(err, "Error while getting client version")
+		return nil, errors.Wrap(err, "min api version check: error while getting client version")
 	}
 
 	clients := make(map[DockerVersion]dockeriface.Client)
@@ -164,7 +162,7 @@ func findDockerVersionsfromMinMaxVersions(endpoint string) (map[DockerVersion]do
 		for _, version := range getKnownAPIVersions() {
 			dockerClient, err := getDockerClientForVersion(endpoint, string(version), minAPIVersion, apiVersion)
 			if err != nil {
-				log.Infof("Error getting client version: %v", err)
+				log.Debugf("unable to get Docker client for version %s: %v", version, err)
 				continue
 			}
 			clients[version] = dockerClient
@@ -184,19 +182,19 @@ func getDockerClientForVersion(
 	minVersionCheck, minErr := utils.Version(version).Matches(lessThanMinCheck)
 	maxVersionCheck, maxErr := utils.Version(version).Matches(moreThanMaxCheck)
 	if minErr != nil {
-		return nil, errors.Wrapf(minErr, "Error while comparing version %s with minAPIVersion %s", version, minAPIVersion)
+		return nil, errors.Wrapf(minErr, "error while comparing version %s with minAPIVersion %s", version, minAPIVersion)
 	}
 	if maxErr != nil {
-		return nil, errors.Wrapf(minErr, "Error while comparing version %s with apiVersion %s", version, apiVersion)
+		return nil, errors.Wrapf(minErr, "error while comparing version %s with apiVersion %s", version, apiVersion)
 	}
 	// do not add the version when it is less than min api version or greater
 	// than api version
 	if minVersionCheck || maxVersionCheck {
-		return nil, errors.Errorf("Min and API versions comparison check failed for version: %s", version)
+		return nil, errors.Errorf("min and API versions comparison check failed for version: %s", version)
 	}
 	client, err := newVersionedClient(endpoint, string(version))
 	if err != nil {
-		return nil, errors.Wrap(err, "Error while creating client")
+		return nil, errors.Wrapf(err, "unable to create Docker client for version: %s", version)
 	}
 	return client, nil
 }

agent/engine/dockerclient/dockerclientfactory_windows_test.go

@@ -32,7 +32,7 @@ func TestGetClientMinimumVersion(t *testing.T) {
 
 	newVersionedClient = func(endpoint, version string) (dockeriface.Client, error) {
 		mockClient := mock_dockeriface.NewMockClient(ctrl)
-		if version == string(MinDockerAPIWindows) {
+		if version == string(minDockerAPIVersion) {
 			mockClient = expectedClient
 		}
 		mockClient.EXPECT().Version().Return(&docker.Env{}, nil).AnyTimes()

agent/engine/dockerclient/versionsupport_unix.go

@@ -18,6 +18,10 @@ import (
 	"github.com/aws/amazon-ecs-agent/agent/engine/dockeriface"
 )
 
+const (
+	// minDockerAPIVersion is the min Docker API version supported by agent
+	minDockerAPIVersion = Version_1_17
+)
 // GetClient on linux will simply return the cached client from the map
 func (f *factory) GetClient(version DockerVersion) (dockeriface.Client, error) {
 	return f.getClient(version)

agent/engine/dockerclient/versionsupport_windows.go

@@ -18,14 +18,14 @@ import (
 	"github.com/aws/amazon-ecs-agent/agent/engine/dockeriface"
 )
 
-const MinDockerAPIWindows = Version_1_24
+const minDockerAPIVersion = Version_1_24
 
 // GetClient will replace some versions of Docker on Windows. We need this because
 // agent assumes that it can always call older versions of the docker API.
 func (f *factory) GetClient(version DockerVersion) (dockeriface.Client, error) {
 	for _, v := range getWindowsReplaceableVersions() {
 		if v == version {
-			version = MinDockerAPIWindows
+			version = minDockerAPIVersion
 			break
 		}
 	}
@@ -48,10 +48,10 @@ func getWindowsReplaceableVersions() []DockerVersion {
 
 // getAgentVersions for Windows should return all of the replaceable versions plus additional versions
 func getAgentVersions() []DockerVersion {
-	return append(getWindowsReplaceableVersions(), MinDockerAPIWindows)
+	return append(getWindowsReplaceableVersions(), minDockerAPIVersion)
 }
 
 // getDefaultVersion returns agent's default version of the Docker API
 func getDefaultVersion() DockerVersion {
-	return MinDockerAPIWindows
+	return minDockerAPIVersion
 }

agent/utils/compare_versions.go

@@ -136,6 +136,7 @@ func parseSemver(version string) (semver, error) {
 	return result, nil
 }
 
+// TODO: remove this logic once non-semver comparator is implemented
 func appendIfNoPatch(version string) string {
 	versionParts := strings.Split(version, ".")
 	// Only major and minor versions are present