feat(configuration): env config file discovery (#4618)

This allows Authelia to discover config files and config options via environment variables.

Co-authored-by: Amir Zarrinkafsh <nightah@me.com>

Dockerfile

@@ -11,7 +11,8 @@ WORKDIR /app
 # Set environment variables
 ENV PATH="/app:${PATH}" \
     PUID=0 \
-    PGID=0
+    PGID=0 \
+    X_AUTHELIA_CONFIG="/config/configuration.yml"
 
 RUN \
 	apk --no-cache add ca-certificates su-exec tzdata
@@ -28,5 +29,4 @@ EXPOSE 9091
 VOLUME /config
 
 ENTRYPOINT ["/app/entrypoint.sh"]
-CMD ["--config", "/config/configuration.yml"]
 HEALTHCHECK --interval=30s --timeout=3s --start-period=1m CMD /app/healthcheck.sh

Dockerfile.coverage

@@ -58,7 +58,8 @@ EXPOSE 9091
 
 VOLUME /config
 
-ENV PATH="/app:${PATH}"
+ENV PATH="/app:${PATH}" \
+    X_AUTHELIA_CONFIG="/config/configuration.yml"
 
-CMD ["authelia", "-test.coverprofile=/authelia/coverage.txt", "COVERAGE", "--config", "/config/configuration.yml"]
+CMD ["authelia", "-test.coverprofile=/authelia/coverage.txt", "COVERAGE"]
 HEALTHCHECK --interval=30s --timeout=3s CMD /app/healthcheck.sh

Dockerfile.dev

@@ -50,7 +50,8 @@ WORKDIR /app
 # Set environment variables
 ENV PATH="/app:${PATH}" \
     PUID=0 \
-    PGID=0
+    PGID=0 \
+    X_AUTHELIA_CONFIG="/config/configuration.yml"
 
 RUN \
 	apk --no-cache add ca-certificates su-exec tzdata
@@ -65,5 +66,4 @@ EXPOSE 9091
 VOLUME /config
 
 ENTRYPOINT ["/app/entrypoint.sh"]
-CMD ["--config", "/config/configuration.yml"]
 HEALTHCHECK --interval=30s --timeout=3s --start-period=1m CMD /app/healthcheck.sh

docs/content/en/configuration/methods/files.md

@@ -12,18 +12,23 @@ weight: 101200
 toc: true
 ---
 
-## Loading Behaviour
+## Loading Behaviour and Discovery
 
 There are several options which affect the loading of files:
 
-|       Name        |            Argument             |                                    Description                                     |
+|       Name        |            Argument             |    Environment Variable     |                                    Description                                     |
-|:-----------------:|:-------------------------------:|:----------------------------------------------------------------------------------:|
+|:-----------------:|:-------------------------------:|:---------------------------:|:----------------------------------------------------------------------------------:|
-| Files/Directories |        `--config`, `-c`         | A list of file or directory (non-recursive) paths to load configuration files from |
+| Files/Directories |        `--config`, `-c`         |     `X_AUTHELIA_CONFIG`     | A list of file or directory (non-recursive) paths to load configuration files from |
-|      Filters      | `--config.experimental.filters` |   A list of filters applied to every file from the Files or Directories options    |
+|      Filters      | `--config.experimental.filters` | `X_AUTHELIA_CONFIG_FILTERS` |   A list of filters applied to every file from the Files or Directories options    |
 
 __*Note:* when specifying directories and files, the individual files specified must not be within any of the
 directories specified.__
 
+Configuration options can be discovered via either the Argument or Environment Variable, but not both at the same time.
+If both are specified the Argument takes precedence and the Environment Variable is ignored. It is generally recommended
+that if you're using a container that you use the Environment Variable as this will allow you to execute other commands
+from the context of the container more easily.
+
 ## Formats
 
 The only supported configuration file format is [YAML](#yaml).

internal/commands/const.go

@@ -538,8 +538,10 @@ const (
 	cmdConfigDefaultDaemon    = "/etc/authelia/configuration.yml"
 
 	cmdFlagNameConfig    = "config"
+	cmdFlagEnvNameConfig = "X_AUTHELIA_CONFIG"
 
 	cmdFlagNameConfigExpFilters = "config.experimental.filters"
+	cmdFlagEnvNameConfigFilters = "X_AUTHELIA_CONFIG_FILTERS"
 
 	cmdFlagNameCharSet     = "charset"
 	cmdFlagValueCharSet    = "alphanumeric"
@@ -655,4 +657,42 @@ The following filters are available:
 		'expand-env' filter for example.
 
 		For a full list of functions see: https://www.authelia.com/configuration/methods/files/#functions`
+
+	helpTopicConfig = `Configuration can be specified in multiple layers where each layer is a different source from
+the last. The layers are loaded in the order below where each layer potentially overrides the individual settings from
+previous layers with the individual settings it provides (i.e. if the same setting is specified twice).
+
+Layers:
+  - File/Directory Paths
+  - Environment Variables
+  - Secrets
+
+File/Directory Paths:
+
+	File/Directory Paths can be specified either via the '--config' CLI argument or the 'X_AUTHELIA_CONFIG' environment
+	variable. If both the environment variable AND the CLI argument are specified the environment variable is completely
+	ignored. These values both take lists separated by commas.
+
+	Directories that are loaded via this method load all files with relevant extensions from the directory, this is not
+    recursive. This means all files with these extensions must be Authelia configuration files with valid syntax.
+
+	The paths specified are loaded in order, where individual settings specified by later files potentially overrides
+	individual settings by later files (i.e. if the same setting is specified twice). Files specified Files in
+	directories are loaded in lexicographic order.
+
+	The files loaded via this method can be interpolated or templated via the configuration filters. Read more about
+	this topic by running: authelia -h authelia filters
+
+Environment Variables:
+
+	Most configuration options in Authelia can be specified via an environment variable. The available options and the
+	specific environment variable mapping can be found here: https://www.authelia.com/configuration/methods/environment/
+
+Secrets:
+
+	Some configuration options in Authelia can be specified via an environment variable which refers to the location of
+	a file; also known as a secret. Every configuration key that ends with the following strings can be loaded in this
+	way: 'key', 'secret', 'password', 'token'.
+
+	The available options and the specific secret mapping can be found here: https://www.authelia.com/configuration/methods/secrets/`
 )

internal/commands/context.go

@@ -277,7 +277,7 @@ func (ctx *CmdCtx) ConfigEnsureExistsRunE(cmd *cobra.Command, _ []string) (err e
 		result  XEnvCLIResult
 	)
 
-	if configs, result, err = loadXEnvCLIStringSliceValue(cmd, "", cmdFlagNameConfig); err != nil {
+	if configs, result, err = loadXEnvCLIStringSliceValue(cmd, cmdFlagEnvNameConfig, cmdFlagNameConfig); err != nil {
 		return err
 	}
 

internal/commands/root.go

@@ -45,9 +45,9 @@ func NewRootCmd() (cmd *cobra.Command) {
 		DisableAutoGenTag: true,
 	}
 
-	cmd.PersistentFlags().StringSliceP(cmdFlagNameConfig, "c", []string{"configuration.yml"}, "configuration files or directories to load")
+	cmd.PersistentFlags().StringSliceP(cmdFlagNameConfig, "c", []string{"configuration.yml"}, "configuration files or directories to load, for more information run 'authelia -h authelia config'")
 
-	cmd.PersistentFlags().StringSlice(cmdFlagNameConfigExpFilters, nil, "list of filters to apply to all configuration files, for more information: authelia --help authelia filters")
+	cmd.PersistentFlags().StringSlice(cmdFlagNameConfigExpFilters, nil, "list of filters to apply to all configuration files, for more information run 'authelia -h authelia filters'")
 
 	cmd.AddCommand(
 		newAccessControlCommand(ctx),
@@ -56,7 +56,8 @@ func NewRootCmd() (cmd *cobra.Command) {
 		newStorageCmd(ctx),
 		newValidateConfigCmd(ctx),
 
-		newHelpTopic("filters", "Help for the config filters", helpTopicConfigFilters),
+		newHelpTopic("config", "Help for the config file/directory paths", helpTopicConfig),
+		newHelpTopic("filters", "help topic for the config filters", helpTopicConfigFilters),
 	)
 
 	return cmd

internal/commands/util.go

@@ -246,7 +246,7 @@ func loadXEnvCLIConfigValues(cmd *cobra.Command) (configs []string, filters []co
 		filterNames []string
 	)
 
-	if configs, _, err = loadXEnvCLIStringSliceValue(cmd, "", cmdFlagNameConfig); err != nil {
+	if configs, _, err = loadXEnvCLIStringSliceValue(cmd, cmdFlagEnvNameConfig, cmdFlagNameConfig); err != nil {
 		return nil, nil, err
 	}
 
@@ -254,7 +254,7 @@ func loadXEnvCLIConfigValues(cmd *cobra.Command) (configs []string, filters []co
 		return nil, nil, err
 	}
 
-	if filterNames, _, err = loadXEnvCLIStringSliceValue(cmd, "", cmdFlagNameConfigExpFilters); err != nil {
+	if filterNames, _, err = loadXEnvCLIStringSliceValue(cmd, cmdFlagEnvNameConfigFilters, cmdFlagNameConfigExpFilters); err != nil {
 		return nil, nil, err
 	}
 

internal/suites/example/compose/authelia/Dockerfile.backend

@@ -11,7 +11,8 @@ RUN mkdir -p /config && chown dev:dev /config
 
 USER dev
 
-ENV PATH="/app:${PATH}"
+ENV PATH="/app:${PATH}" \
+	X_AUTHELIA_CONFIG="/config/configuration.yml"
 
 VOLUME /config
 

internal/suites/example/compose/authelia/Dockerfile.frontend

@@ -4,7 +4,6 @@ ARG USER_ID
 ARG GROUP_ID
 
 RUN yarn global add pnpm && \
-    pnpm config set --global store-dir /tmp/.pnpm-store && \
     deluser node && \
     addgroup --gid ${GROUP_ID} dev && \
     adduser --uid ${USER_ID} -G dev -D dev

internal/suites/example/compose/authelia/docker-compose.frontend.dev.yml

@@ -14,7 +14,7 @@ services:
     volumes:
       - './example/compose/authelia/resources/:/resources'
       - '../../web:/app'
-      - '~/.local/share/pnpm/store:/tmp/.pnpm-store'
+      - '~/.local/share/pnpm/store:/app/.pnpm-store'
     labels:
       # Traefik 1.x
       - 'traefik.frontend.rule=Host:login.example.com'

internal/suites/example/compose/authelia/resources/run-backend-dev.sh

@@ -4,6 +4,6 @@ set -e
 
 while true;
 do
-    AUTHELIA_SERVER_DISABLE_HEALTHCHECK=true CGO_ENABLED=1 dlv --listen 0.0.0.0:2345 --headless=true --output=./authelia --continue --accept-multiclient debug cmd/authelia/*.go -- --config /config/configuration.yml
+    AUTHELIA_SERVER_DISABLE_HEALTHCHECK=true CGO_ENABLED=1 dlv --listen 0.0.0.0:2345 --headless=true --output=./authelia --continue --accept-multiclient debug cmd/authelia/*.go
     sleep 10
 done

internal/suites/suite_cli_test.go

@@ -10,7 +10,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/suite"
-	yaml "gopkg.in/yaml.v3"
+	"gopkg.in/yaml.v3"
 
 	"github.com/authelia/authelia/v4/internal/model"
 	"github.com/authelia/authelia/v4/internal/storage"
@@ -73,7 +73,7 @@ func (s *CLISuite) TestShouldPrintVersion() {
 }
 
 func (s *CLISuite) TestShouldValidateConfig() {
-	output, err := s.Exec("authelia-backend", []string{"authelia", s.testArg, s.coverageArg, "validate-config", "--config=/config/configuration.yml"})
+	output, err := s.Exec("authelia-backend", []string{"authelia", s.testArg, s.coverageArg, "validate-config"})
 	s.Assert().NoError(err)
 	s.Assert().Contains(output, "Configuration parsed and loaded successfully without errors.")
 }