distroless: rewrite docker-entrypoint.sh in go

See go doc ./cmd/docker-entrypoint for why. Signed-off-by: Andrew Keesler <akeesler@vmware.com>
2022-01-18 12:24:05 -05:00
parent ba1bd65c10
commit 764ce711b6
5 changed files with 208 additions and 35 deletions
--- a/cmd/docker-entrypoint/main_test.go
+++ b/cmd/docker-entrypoint/main_test.go
@@ -0,0 +1,113 @@
+package main
+
+import (
+	"strings"
+	"testing"
+)
+
+type execArgs struct {
+	fork        bool
+	argPrefixes []string
+}
+
+func TestRun(t *testing.T) {
+	tests := []struct {
+		name         string
+		args         []string
+		execReturns  error
+		whichReturns string
+		wantExecArgs []execArgs
+		wantErr      error
+	}{
+		{
+			name:         "executable not dex",
+			args:         []string{"tuna", "fish"},
+			wantExecArgs: []execArgs{{fork: false, argPrefixes: []string{"tuna", "fish"}}},
+		},
+		{
+			name:         "executable is full path to dex",
+			args:         []string{"/usr/local/bin/dex", "marshmallow", "zelda"},
+			whichReturns: "/usr/local/bin/dex",
+			wantExecArgs: []execArgs{{fork: false, argPrefixes: []string{"/usr/local/bin/dex", "marshmallow", "zelda"}}},
+		},
+		{
+			name:         "command is not serve",
+			args:         []string{"dex", "marshmallow", "zelda"},
+			wantExecArgs: []execArgs{{fork: false, argPrefixes: []string{"dex", "marshmallow", "zelda"}}},
+		},
+		{
+			name:         "no templates",
+			args:         []string{"dex", "serve", "config.yaml.not-a-template"},
+			wantExecArgs: []execArgs{{fork: false, argPrefixes: []string{"dex", "serve", "config.yaml.not-a-template"}}},
+		},
+		{
+			name:         "no templates",
+			args:         []string{"dex", "serve", "config.yaml.not-a-template"},
+			wantExecArgs: []execArgs{{fork: false, argPrefixes: []string{"dex", "serve", "config.yaml.not-a-template"}}},
+		},
+		{
+			name: ".tpl template",
+			args: []string{"dex", "serve", "config.tpl"},
+			wantExecArgs: []execArgs{
+				{fork: true, argPrefixes: []string{"gomplate", "-f", "config.tpl", "-o", "/tmp/dex.config.yaml-"}},
+				{fork: false, argPrefixes: []string{"dex", "serve", "/tmp/dex.config.yaml-"}},
+			},
+		},
+		{
+			name: ".tmpl template",
+			args: []string{"dex", "serve", "config.tmpl"},
+			wantExecArgs: []execArgs{
+				{fork: true, argPrefixes: []string{"gomplate", "-f", "config.tmpl", "-o", "/tmp/dex.config.yaml-"}},
+				{fork: false, argPrefixes: []string{"dex", "serve", "/tmp/dex.config.yaml-"}},
+			},
+		},
+		{
+			name: ".yaml template",
+			args: []string{"dex", "serve", "some/path/config.yaml"},
+			wantExecArgs: []execArgs{
+				{fork: true, argPrefixes: []string{"gomplate", "-f", "some/path/config.yaml", "-o", "/tmp/dex.config.yaml-"}},
+				{fork: false, argPrefixes: []string{"dex", "serve", "/tmp/dex.config.yaml-"}},
+			},
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			var gotExecForks []bool
+			var gotExecArgs [][]string
+			fakeExec := func(fork bool, args ...string) error {
+				gotExecForks = append(gotExecForks, fork)
+				gotExecArgs = append(gotExecArgs, args)
+				return test.execReturns
+			}
+
+			fakeWhich := func(_ string) string { return test.whichReturns }
+
+			gotErr := run(test.args, fakeExec, fakeWhich)
+			if (test.wantErr == nil) != (gotErr == nil) {
+				t.Errorf("wanted error %s, got %s", test.wantErr, gotErr)
+			}
+			if !execArgsMatch(test.wantExecArgs, gotExecForks, gotExecArgs) {
+				t.Errorf("wanted exec args %+v, got %+v %+v", test.wantExecArgs, gotExecForks, gotExecArgs)
+			}
+		})
+	}
+}
+
+func execArgsMatch(wantExecArgs []execArgs, gotForks []bool, gotExecArgs [][]string) bool {
+	if len(wantExecArgs) != len(gotForks) {
+		return false
+	}
+
+	for i := range wantExecArgs {
+		if wantExecArgs[i].fork != gotForks[i] {
+			return false
+		}
+		for j := range wantExecArgs[i].argPrefixes {
+			if !strings.HasPrefix(gotExecArgs[i][j], wantExecArgs[i].argPrefixes[j]) {
+				return false
+			}
+		}
+	}
+
+	return true
+}