Merge pull request #384 from coveooss/fix/DT-5198-DT-5199-min-docker-…

…version

don't set the API_VERSION anymore, ensure minimum version through code

.gitignore

@@ -1,4 +1,5 @@
 .idea
+.fleet
 .pkg
 dist
 vendor

README.md

@@ -168,7 +168,7 @@ Check for new version at https://github.com/coveooss/tgf/releases/latest.
 
 Any docker image could be used, but TGF specialized images could be found at: https://hub.docker.com/r/coveo/tgf/tags.
 
-Terragrunt documentation could be found at https://github.com/coveo/terragrunt/blob/master/README.md (Coveo fork)
+Terragrunt documentation could be found at https://github.com/coveo/terragrunt/blob/master/README.md (Coveo fork).
 
 Terraform documentation could be found at https://www.terraform.io/docs/index.html.
 

docker.go

@@ -33,13 +33,13 @@ import (
 )
 
 const (
-	minimumDockerVersion = "1.25"
-	tgfImageVersion      = "TGF_IMAGE_VERSION"
-	dockerSocketFile     = "/var/run/docker.sock"
-	dockerfilePattern    = "TGF_dockerfile"
-	maxDockerTagLength   = 128
-	dockerMountImagePath = "/var/tgf"
-	dockerVolumeName     = "tgf"
+	allowedDockerVersions = ">=1.32.0"
+	tgfImageVersion       = "TGF_IMAGE_VERSION"
+	dockerSocketFile      = "/var/run/docker.sock"
+	dockerfilePattern     = "TGF_dockerfile"
+	maxDockerTagLength    = 128
+	dockerMountImagePath  = "/var/tgf"
+	dockerVolumeName      = "tgf"
 )
 
 type dockerConfig struct{ *TGFConfig }
@@ -415,12 +415,36 @@ func (docker *dockerConfig) GetActualImageVersion() string {
 	return getActualImageVersionInternal(docker.getImage())
 }
 
+func validateDockerVersion(version string) (bool, error) {
+	v, err := semver.ParseTolerant(version)
+	if err != nil {
+		return false, fmt.Errorf("Cannot parse %s: %w", version, err)
+	}
+
+	expectedRange, err := semver.ParseRange(allowedDockerVersions)
+	if err != nil {
+		// this is a developer error, allowedDockerVersions is a const
+		log.Panicf("Unable to parse range: %s: %v", allowedDockerVersions, err)
+	}
+
+	return expectedRange(v), nil
+}
+
 func getDockerClient() (*client.Client, context.Context) {
 	if dockerClient == nil {
-		os.Setenv("DOCKER_API_VERSION", minimumDockerVersion)
 		dockerClient = must(client.NewClientWithOpts(client.FromEnv)).(*client.Client)
 		dockerContext = context.Background()
 	}
+
+	currentVersion := dockerClient.ClientVersion()
+	valid, err := validateDockerVersion(currentVersion)
+
+	if err != nil {
+		log.Errorf("Skipping Docker API validation because of an error: %v", err)
+	} else if !valid {
+		log.Fatalf("Docker API reported version %s which is too old, required version range is %s", currentVersion, allowedDockerVersions)
+	}
+
 	return dockerClient, dockerContext
 }
 

docker_version_test.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDockerVersion(t *testing.T) {
+	dockerClient, _ := getDockerClient()
+
+	tests := []struct {
+		name    string
+		version string
+		valid   bool
+	}{
+		{
+			name:    "Current docker version",
+			version: dockerClient.ClientVersion(),
+			valid:   true, // this unit test depends on the environment
+		},
+		{
+			name:    "Minimum version",
+			version: "1.32",
+			valid:   true,
+		},
+		{
+			name:    "They patched the minimum version",
+			version: "1.32.1",
+			valid:   true,
+		},
+		{
+			name:    "More recent version",
+			version: "1.35",
+			valid:   true,
+		},
+		{
+			name:    "New major",
+			version: "2.0",
+			valid:   true,
+		},
+
+		{
+			name:    "Too old",
+			version: "1.31.0",
+			valid:   false,
+		},
+	}
+
+	assert := assert.New(t)
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			valid, err := validateDockerVersion(tt.version)
+			assert.NoError(err)
+			assert.Equal(valid, tt.valid)
+		})
+	}
+}
+
+func TestGetDockerClient(t *testing.T) {
+	dockerClient, _ := getDockerClient()
+	valid, err := validateDockerVersion(dockerClient.ClientVersion())
+
+	assert.NoError(t, err)
+	assert.True(t, valid)
+}