{"record":{"id":"c0e3beba79c057b9","repo":"slimtoolkit/slim","slug":"getdatatype-error-getting-data-type-s-stderr","errorCode":null,"errorMessage":"getDataType - error getting data type: %s / stderr: %s","messagePattern":"getDataType - error getting data type: (.+?) / stderr: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/app/sensor/artifact/artifact.go","lineNumber":2829,"sourceCode":"\thash := sha1.Sum(fileData)\n\treturn hex.EncodeToString(hash[:]), nil\n}\n\nfunc getDataType(artifactFileName string) (string, error) {\n\t//TODO: use libmagic (pure impl)\n\tvar cerr bytes.Buffer\n\tvar cout bytes.Buffer\n\n\tcmd := exec.Command(fileTypeCmd, artifactFileName)\n\tcmd.Stderr = &cerr\n\tcmd.Stdout = &cout\n\n\tif err := cmd.Start(); err != nil {\n\t\treturn \"\", err\n\t}\n\n\tif err := cmd.Wait(); err != nil {\n\t\terr = fmt.Errorf(\"getDataType - error getting data type: %s / stderr: %s\", err, cerr.String())\n\t\treturn \"\", err\n\t}\n\n\tif typeInfo := strings.Split(strings.TrimSpace(cout.String()), \":\"); len(typeInfo) > 1 {\n\t\treturn strings.TrimSpace(typeInfo[1]), nil\n\t}\n\n\treturn \"unknown\", nil\n}\n\n/*\n\n\nfunc cpFile(src, dst string) error {\n\ts, err := os.Open(src)\n\tif err != nil {\n\t\tlog.Warnln(\"sensor: monitor - cp - error opening source file =>\", src)\n\t\treturn err","sourceCodeStart":2811,"sourceCodeEnd":2847,"githubUrl":"https://github.com/slimtoolkit/slim/blob/81940d17fa112cc678e32209214bcb2355cb3004/pkg/app/sensor/artifact/artifact.go#L2811-L2847","documentation":"getDataType runs an external command (the 'file' type detector) and captures stdout/stderr. If cmd.Wait returns a non-zero exit, the function wraps both the exec error and the captured stderr into this message and returns it. It is the error path of detecting an artifact's data type from its content.","triggerScenarios":"The type-detection command exits non-zero: the 'file' binary is missing in the container image, the analyzed path does not exist or is unreadable, or the command is killed (OOM/signals).","commonSituations":"Minimal distroless container images lacking the file(1) utility; analyzing a file that was deleted mid-scan; PATH not set in the sensor's execution environment.","solutions":["Read the stderr portion of the message to see the detector's actual failure reason.","Ensure the 'file' (or equivalent) command exists in the image and is on PATH.","Verify the path being type-checked exists and is readable by the sensor user.","Add a fallback that treats unknown type as a default (e.g. binary) instead of failing the whole artifact scan."],"exampleFix":"// before\nif err := cmd.Wait(); err != nil {\n    err = fmt.Errorf(\"getDataType - error getting data type: %s / stderr: %s\", err, cerr.String())\n    return \"\", err\n}\n// after\nif err := cmd.Wait(); err != nil {\n    log.Debugf(\"getDataType fallback for %s: %v / %s\", path, err, cerr.String())\n    return \"\", fmt.Errorf(\"getDataType - error getting data type: %w / stderr: %s\", err, cerr.String())\n}","handlingStrategy":"fallback","validationCode":"if _, err := exec.LookPath(fileTypeCmd); err != nil {\n    return \"\", fmt.Errorf(\"type detector %q not on PATH: %w\", fileTypeCmd, err)\n}\nif _, err := os.Stat(path); err != nil {\n    return \"\", fmt.Errorf(\"cannot type-check missing path %q: %w\", path, err)\n}","typeGuard":null,"tryCatchPattern":"dataType, err := getDataType(path)\nif err != nil {\n    if strings.Contains(err.Error(), \"getDataType - error getting data type\") {\n        log.Warnf(\"type detection failed, assuming binary: %v\", err)\n        dataType = \"application/octet-stream\" // fallback default\n    } else {\n        return err\n    }\n}","preventionTips":["Include the file(1) utility in container images used for artifact scanning","Set PATH explicitly in the sensor's execution environment","Verify the target file exists before invoking the detector"],"tags":["exec","command-exit","file-type-detection","sensor"],"backgroundTag":"command-exited-nonzero","analyzedSha":"81940d17fa112cc678e32209214bcb2355cb3004","analyzedAt":"2026-08-31T23:06:12.682Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T05:18:18.240Z"}