Missing Dnf Clean All

Query id: 295acb63-9246-4b21-b441-7c1f1fb62dc0
Query name: Missing Dnf Clean All
Platform: Dockerfile
Severity: Low
Category: Best Practices
URL: Github

Description¶

Cached package data should be cleaned after installation to reduce image size
Documentation

Code samples¶

Code samples with security vulnerabilities¶

Positive test num. 1 - dockerfile file

FROM fedora:27
RUN set -uex && \
    dnf config-manager --add-repo https://download.docker.com/linux/fedora/docker-ce.repo && \
    sed -i 's/\$releasever/26/g' /etc/yum.repos.d/docker-ce.repo && \
    dnf install -vy docker-ce
HEALTHCHECK CMD curl --fail http://localhost:3000 || exit 1

Code samples without security vulnerabilities¶

Negative test num. 1 - dockerfile file

FROM fedora:27
RUN set -uex && \
    dnf config-manager --add-repo https://download.docker.com/linux/fedora/docker-ce.repo && \
    sed -i 's/\$releasever/26/g' /etc/yum.repos.d/docker-ce.repo && \
    dnf install -vy docker-ce && \
    dnf clean all
HEALTHCHECK CMD curl --fail http://localhost:3000 || exit 1

Negative test num. 2 - dockerfile file

FROM golang:1.16 AS builder
WORKDIR /go/src/github.com/foo/href-counter/
RUN go get -d -v golang.org/x/net/html  
COPY app.go    ./
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .
RUN set -uex && \
    dnf config-manager --add-repo https://download.docker.com/linux/fedora/docker-ce.repo && \
    sed -i 's/\$releasever/26/g' /etc/yum.repos.d/docker-ce.repo && \
    dnf install -vy docker-ce

FROM alpine:latest  
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=builder /go/src/github.com/foo/href-counter/app ./
CMD ["./app"]
RUN useradd -ms /bin/bash patrick

USER patrick