CODEWITHSUNDEEP
dockerdockerfile
Fauzan
Fauzan

Reputation: 755

What is the different of . and ./ in RUN

I got best practice of vue dockerfile like this :

FROM node:lts-alpine as build-stage
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
RUN npm run build

I wonder what is the different of the target like first COPY ./ and second COPY . ?

Upvotes: 0

Views: 86

Answers (1)

grapes
grapes

Reputation: 8646

When you have several sources, you are obligated to use ./ form, which explicitly specifies that the target is a folder, into which all sources are copied. So, COPY a b ./ will make ./a and ./b inside container.

When you have single source like COPY . . this command merges source folder content into destination folder or replaces the file (if source is a file).

Best shown in an example. Lets say you have:

a/
  a.txt
b/
  b.txt
Dockerfile
hello.txt

Dockerfile

COPY hello.txt ./hello1    # will create/replace ./hello1 FILE in container
COPY hello.txt ./hello2/  # will create ./hello2/hello.txt 
COPY a .     # now you have ./a.txt in container
COPY b .     # now you have ./a.txt and ./b.txt in container

Finally you get in container:

hello1
hello2/hello.txt
a.txt
b.txt

Upvotes: 3

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