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//! DOCKER005: Missing --no-install-recommends (image size optimization)
//!
//! Equivalent to hadolint DL3015
//!
//! **Rule**: apt-get install should use --no-install-recommends
//!
//! **Why this matters**:
//! By default, apt-get installs recommended packages, significantly
//! increasing image size. Use --no-install-recommends to install only
//! required dependencies.
//!
//! ## Examples
//!
//! ❌ **BAD** (installs recommended packages):
//! ```dockerfile
//! RUN apt-get update && apt-get install -y curl
//! ```
//!
//! ✅ **GOOD** (minimal installation):
//! ```dockerfile
//! RUN apt-get update && \
//! apt-get install -y --no-install-recommends curl && \
//! rm -rf /var/lib/apt/lists/*
//! ```
use crate::linter::{Diagnostic, LintResult, Severity, Span};
pub fn check(source: &str) -> LintResult {
let mut result = LintResult::new();
for (line_num, line) in source.lines().enumerate() {
let trimmed = line.trim();
if trimmed.contains("apt-get install") && !trimmed.contains("--no-install-recommends") {
let span = Span::new(line_num + 1, 1, line_num + 1, trimmed.len().min(80));
let diag = Diagnostic::new(
"DOCKER005",
Severity::Info,
"apt-get install without --no-install-recommends increases image size (hadolint DL3015)".to_string(),
span,
);
result.add(diag);
}
}
result
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_DOCKER005_missing_no_install_recommends() {
let dockerfile = "RUN apt-get install -y curl\n";
let result = check(dockerfile);
assert_eq!(result.diagnostics.len(), 1);
assert_eq!(result.diagnostics[0].code, "DOCKER005");
}
#[test]
fn test_DOCKER005_has_no_install_recommends() {
let dockerfile = "RUN apt-get install -y --no-install-recommends curl\n";
let result = check(dockerfile);
assert_eq!(result.diagnostics.len(), 0);
}
}