feat(config): Allow avoiding reading default config file (#2227)

Signed-off-by: Dave Henderson <dhenderson@gmail.com>

.github/workflows/docs.yml

@@ -52,5 +52,7 @@ jobs:
  --exclude="https://docs\.aws.*" \
  --exclude="https://linux.die\.net.*" \
  --exclude="https://jqplay\.org.*" \
+ --exclude="https://json\.org.*" \
+ --exclude="https://goessner\.net.*"
 
  kill %1

docs/content/usage.md

@@ -21,7 +21,7 @@ Hello, hairyhenderson
 
 ### `--config`
 
-Specify the path to a [gomplate config file](../config). The default is `.gomplate.yaml`. Can also be set with the `GOMPLATE_CONFIG` environment variable.
+Specify the path to a [gomplate config file](../config). The default is `.gomplate.yaml`. Can also be set with the `GOMPLATE_CONFIG` environment variable. Setting `--config` or `GOMPLATE_CONFIG` to an empty string (`--config=""` or `export GOMPLATE_CONFIG=""`) will disable the use of a config file, skipping the default `.gomplate.yaml` file.
 
 For example:
 

env/env.go

@@ -20,3 +20,13 @@ func ExpandEnv(s string) string {
  fsys := datafs.WrapWdFS(osfs.NewFS())
  return datafs.ExpandEnvFsys(fsys, s)
 }
+
+// LookupEnv - retrieves the value of the environment variable named by the key.
+// If the variable is unset, but the same variable ending in `_FILE` is set, the
+// referenced file will be read into the value. If the key is not set, the
+// second return value will be false.
+// Otherwise the provided default (or an emptry string) is returned.
+func LookupEnv(key string) (string, bool) {
+ fsys := datafs.WrapWdFS(osfs.NewFS())
+ return datafs.LookupEnvFsys(fsys, key)
+}

internal/cmd/config.go

@@ -57,22 +57,34 @@ func loadConfig(ctx context.Context, cmd *cobra.Command, args []string) (*gompla
  return cfg, nil
 }
 
-func pickConfigFile(cmd *cobra.Command) (cfgFile string, required bool) {
+func pickConfigFile(cmd *cobra.Command) (cfgFile string, required, skip bool) {
  cfgFile = defaultConfigFile
- if c := env.Getenv("GOMPLATE_CONFIG"); c != "" {
+ if c, found := env.LookupEnv("GOMPLATE_CONFIG"); found {
  cfgFile = c
- required = true
+ if cfgFile == "" {
+ skip = true
+ } else {
+ required = true
+ }
  }
- if cmd.Flags().Changed("config") && cmd.Flag("config").Value.String() != "" {
+ if cmd.Flags().Changed("config") {
  // Use config file from the flag if specified
  cfgFile = cmd.Flag("config").Value.String()
- required = true
+ if cfgFile == "" {
+ skip = true
+ } else {
+ required = true
+ }
  }
- return cfgFile, required
+ return cfgFile, required, skip
 }
 
 func readConfigFile(ctx context.Context, cmd *cobra.Command) (*gomplate.Config, error) {
- cfgFile, configRequired := pickConfigFile(cmd)
+ cfgFile, configRequired, skip := pickConfigFile(cmd)
+ if skip {
+ // --config was specified with an empty value
+ return nil, nil
+ }
 
  // we only support loading configs from the local filesystem for now
  fsys, err := datafs.FSysForPath(ctx, cfgFile)

internal/cmd/config_test.go

@@ -188,29 +188,49 @@ func TestPickConfigFile(t *testing.T) {
  cmd.Flags().String("config", defaultConfigFile, "foo")
 
  t.Run("default", func(t *testing.T) {
- cf, req := pickConfigFile(cmd)
+ cf, req, skip := pickConfigFile(cmd)
  assert.False(t, req)
+ assert.False(t, skip)
  assert.Equal(t, defaultConfigFile, cf)
  })
 
  t.Run("GOMPLATE_CONFIG env var", func(t *testing.T) {
  t.Setenv("GOMPLATE_CONFIG", "foo.yaml")
- cf, req := pickConfigFile(cmd)
+ cf, req, skip := pickConfigFile(cmd)
  assert.True(t, req)
+ assert.False(t, skip)
  assert.Equal(t, "foo.yaml", cf)
  })
 
  t.Run("--config flag", func(t *testing.T) {
  cmd.ParseFlags([]string{"--config", "config.file"})
- cf, req := pickConfigFile(cmd)
+ cf, req, skip := pickConfigFile(cmd)
  assert.True(t, req)
+ assert.False(t, skip)
  assert.Equal(t, "config.file", cf)
 
  t.Setenv("GOMPLATE_CONFIG", "ignored.yaml")
- cf, req = pickConfigFile(cmd)
+ cf, req, skip = pickConfigFile(cmd)
  assert.True(t, req)
+ assert.False(t, skip)
  assert.Equal(t, "config.file", cf)
  })
+
+ t.Run("--config flag with empty value should skip reading", func(t *testing.T) {
+ cmd.ParseFlags([]string{"--config", ""})
+ cf, req, skip := pickConfigFile(cmd)
+ assert.False(t, req)
+ assert.True(t, skip)
+ assert.Equal(t, "", cf)
+ })
+
+ t.Run("GOMPLATE_CONFIG env var with empty value should skip reading", func(t *testing.T) {
+ t.Setenv("GOMPLATE_CONFIG", "")
+ cf, req, skip := pickConfigFile(cmd)
+ assert.False(t, req)
+ assert.True(t, skip)
+ assert.Equal(t, "", cf)
+ })
 }
 
 func TestApplyEnvVars(t *testing.T) {

internal/datafs/getenv.go

@@ -15,30 +15,36 @@ func ExpandEnvFsys(fsys fs.FS, s string) string {
 
 // GetenvFsys - a convenience function intended for internal use only!
 func GetenvFsys(fsys fs.FS, key string, def ...string) string {
- val := getenvFile(fsys, key)
+ val, _ := getenvFile(fsys, key)
  if val == "" && len(def) > 0 {
  return def[0]
  }
 
  return val
 }
 
-func getenvFile(fsys fs.FS, key string) string {
- val := os.Getenv(key)
+// LookupEnvFsys - a convenience function intended for internal use only!
+func LookupEnvFsys(fsys fs.FS, key string) (string, bool) {
+ return getenvFile(fsys, key)
+}
+
+func getenvFile(fsys fs.FS, key string) (string, bool) {
+ val, found := os.LookupEnv(key)
  if val != "" {
- return val
+ return val, true
  }
 
  p := os.Getenv(key + "_FILE")
  if p != "" {
  val, err := readFile(fsys, p)
  if err != nil {
- return ""
+ return "", false
  }
- return strings.TrimSpace(val)
+
+ return strings.TrimSpace(val), true
  }
 
- return ""
+ return "", found
 }
 
 func readFile(fsys fs.FS, p string) (string, error) {

internal/tests/integration/config_test.go

@@ -153,6 +153,20 @@ func TestConfig_EnvConfigFile(t *testing.T) {
  assertSuccess(t, o, e, err, "yet another alternate config")
 }
 
+func TestConfig_SkipConfigFile(t *testing.T) {
+ tmpDir := setupConfigTest(t)
+
+ // first set a poisoned default config to prove that it's not being read
+ writeFile(t, tmpDir, ".gomplate.yaml", `badyaml`)
+
+ o, e, err := cmd(t, "--config", "", "--in", "foo").withDir(tmpDir.Path()).run()
+ assertSuccess(t, o, e, err, "foo")
+
+ o, e, err = cmd(t, "--in", "foo").withDir(tmpDir.Path()).
+ withEnv("GOMPLATE_CONFIG", "").run()
+ assertSuccess(t, o, e, err, "foo")
+}
+
 func TestConfig_ConfigOverridesEnvDelim(t *testing.T) {
  if isWindows {
  t.Skip()

internal/tests/integration/datasources_consul_test.go

@@ -42,7 +42,8 @@ func setupDatasourcesConsulTest(t *testing.T) (string, *vaultClient) {
  "serf_lan": `+strconv.Itoa(serfLanPort)+`,
  "serf_wan": -1,
  "dns": -1,
- "grpc": -1
+ "grpc": -1,
+ "grpc_tls": -1
  },
  "connect": { "enabled": false }
  }`,