expand env var when loading acquis (#3375)

pkg/acquisition/acquisition.go

@@ -16,6 +16,7 @@ import (
 	tomb "gopkg.in/tomb.v2"
 	"gopkg.in/yaml.v2"
 
+	"github.com/crowdsecurity/go-cs-lib/csstring"
 	"github.com/crowdsecurity/go-cs-lib/trace"
 
 	"github.com/crowdsecurity/crowdsec/pkg/acquisition/configuration"
@@ -232,7 +233,16 @@ func LoadAcquisitionFromFile(config *csconfig.CrowdsecServiceCfg, prom *csconfig
 			return nil, err
 		}
 
-		dec := yaml.NewDecoder(yamlFile)
+		defer yamlFile.Close()
+
+		acquisContent, err := io.ReadAll(yamlFile)
+		if err != nil {
+			return nil, fmt.Errorf("failed to read %s: %w", acquisFile, err)
+		}
+
+		expandedAcquis := csstring.StrictExpand(string(acquisContent), os.LookupEnv)
+
+		dec := yaml.NewDecoder(strings.NewReader(expandedAcquis))
 		dec.SetStrict(true)
 
 		idx := -1

pkg/acquisition/acquisition_test.go

@@ -217,6 +217,7 @@ wowo: ajsajasjas
 
 func TestLoadAcquisitionFromFile(t *testing.T) {
 	appendMockSource()
+	t.Setenv("TEST_ENV", "test_value2")
 
 	tests := []struct {
 		TestName      string
@@ -282,6 +283,13 @@ func TestLoadAcquisitionFromFile(t *testing.T) {
 			},
 			ExpectedError: "while configuring datasource of type file from test_files/bad_filetype.yaml",
 		},
+		{
+			TestName: "from_env",
+			Config: csconfig.CrowdsecServiceCfg{
+				AcquisitionFiles: []string{"test_files/env.yaml"},
+			},
+			ExpectedLen: 1,
+		},
 	}
 	for _, tc := range tests {
 		t.Run(tc.TestName, func(t *testing.T) {
@@ -293,6 +301,13 @@ func TestLoadAcquisitionFromFile(t *testing.T) {
 			}
 
 			assert.Len(t, dss, tc.ExpectedLen)
+			if tc.TestName == "from_env" {
+				mock := dss[0].Dump().(*MockSource)
+				assert.Equal(t, "test_value2", mock.Toto)
+				assert.Equal(t, "foobar", mock.Labels["test"])
+				assert.Equal(t, "${NON_EXISTING}", mock.Labels["non_existing"])
+				assert.Equal(t, log.InfoLevel, mock.logger.Logger.Level)
+			}
 		})
 	}
 }

pkg/acquisition/test_files/env.yaml

@@ -0,0 +1,6 @@
+labels:
+  test: foobar
+  non_existing: ${NON_EXISTING}
+log_level: info
+source: mock
+toto: ${TEST_ENV}