Add some simple e2e tests for executing CLI plugins

To help with this add a bad plugin which produces invalid metadata.

Signed-off-by: Ian Campbell <ijc@docker.com>

cli-plugins/examples/badmeta/main.go

@@ -0,0 +1,19 @@
+package main
+
+// This is not a real plugin, but just returns malformated metadata
+// from the subcommand and otherwise exits with failure.
+
+import (
+	"fmt"
+	"os"
+
+	cliplugins "github.com/docker/cli/cli-plugins"
+)
+
+func main() {
+	if len(os.Args) == 2 && os.Args[1] == cliplugins.MetadataSubcommandName {
+		fmt.Println(`{invalid-json}`)
+		os.Exit(0)
+	}
+	os.Exit(1)
+}

e2e/cli-plugins/run_test.go

@@ -0,0 +1,31 @@
+package cliplugins
+
+import (
+	"testing"
+
+	"gotest.tools/icmd"
+)
+
+func TestRunNonexisting(t *testing.T) {
+	res := icmd.RunCmd(icmd.Command("docker", "nonexistent"))
+	res.Assert(t, icmd.Expected{
+		ExitCode: 1,
+		Err:      "docker: 'nonexistent' is not a docker command.\nSee 'docker --help'",
+	})
+}
+
+func TestRunBad(t *testing.T) {
+	res := icmd.RunCmd(icmd.Command("docker", "badmeta"))
+	res.Assert(t, icmd.Expected{
+		ExitCode: 1,
+		Err:      "docker: 'badmeta' is not a docker command.\nSee 'docker --help'",
+	})
+}
+
+func TestRunGood(t *testing.T) {
+	res := icmd.RunCmd(icmd.Command("docker", "helloworld"))
+	res.Assert(t, icmd.Expected{
+		ExitCode: 0,
+		Out:      "Hello World!",
+	})
+}

scripts/test/e2e/run

@@ -69,6 +69,7 @@ function runtests {
         TEST_SKIP_PLUGIN_TESTS="${SKIP_PLUGIN_TESTS-}" \
         GOPATH="$GOPATH" \
         PATH="$PWD/build/:/usr/bin" \
+        DOCKER_CLI_PLUGIN_EXTRA_DIRS="$PWD/build/plugins-linux-amd64" \
         "$(which go)" test -v ./e2e/... ${TESTFLAGS-}
 }