Multiple CMD Instructions Listed

  • Query id: 41c195f4-fc31-4a5c-8a1b-90605538d49f
  • Query name: Multiple CMD Instructions Listed
  • Platform: Dockerfile
  • Severity: Low
  • Category: Build Process
  • URL: Github

Description

There can only be one CMD instruction in a Dockerfile. If you list more than one CMD then only the last CMD will take effect
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - dockerfile file
FROM golang:1.7.3
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 .

FROM alpine:latest  
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=0 /go/src/github.com/foo/href-counter/app .
CMD ["./app"] 
CMD ["./apps"]

Code samples without security vulnerabilities

Negative test num. 1 - dockerfile file
FROM golang:1.7.3
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 .
CMD ["./app"] 

FROM alpine:latest  
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=0 /go/src/github.com/foo/href-counter/app .
CMD ["./app"]
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 .
CMD ["./app"] 
CMD ["./apps"] 

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