title: How to install pip3 on a linux docker-image using dockerfile
body: <p>I am building a Linux docker-image using a docker file in which there is a command to install python3-dev and pip3. The python3-dev is getting installed perfectly but pip3 is getting errors. What is the proper syntax for installing pip3 </p>
  
  <p>RUN apk add pip3 install --upgrade pip</p>
  
  <p>Error is:</p>
  
  <p>Step 3/3 : RUN apk add pip3 install --upgrade pip                                                                                                                        ---> Running in 71181984d781                                                                                                                                           fetch <a href="http://dl-cdn.alpinelinux.org/alpine/v3.10/main/x86_64/APKINDEX.tar.gz" rel="nofollow noreferrer">http://dl-cdn.alpinelinux.org/alpine/v3.10/main/x86_64/APKINDEX.tar.gz</a>                                                                                            fetch <a href="http://dl-cdn.alpinelinux.org/alpine/v3.10/community/x86_64/APKINDEX.tar.gz" rel="nofollow noreferrer">http://dl-cdn.alpinelinux.org/alpine/v3.10/community/x86_64/APKINDEX.tar.gz</a>                                                                                       ERROR: unsatisfiable constraints:                                                                                                                                         install (missing):                                                                                                                                                        required by: world[install]                                                                                                                                           pip (missing):                                                                                                                                                            required by: world[pip]                                                                                                                                               pip3 (missing):                                                                                                                                                           required by: world[pip3]                                                                                                                                            The command '/bin/sh -c apk add pip3 install --upgrade pip' returned a non-zero code: 3</p>