[RAILS] Error when deploying EC2 on CircleCI

Introduction

Introduced CircleCI in a personal app, When I tried to deploy to EC2, I got some errors, so I will describe the solution.

environment

• ruby 2.6.2
• rails　5.2.4
• EC2

config.yml

version: 2
 
jobs:
    #build job:Create and test a Docker container on CircleCI
    build:
        docker:
            - image: alpine
        steps:
            - checkout
            - run:
                name: Echo Test
                command: echo "CircleCI Test"
    #deploy job:SSH into EC2 and perform the deployment
    deploy:
        machine:
            image: circleci/classic:edge
        steps:
            - checkout
            #Call the private key registered with CircleCI
            - add_ssh_keys:
            #SSH using environment variables registered with CircleCI
            - run: ssh ${USER_NAME}@${HOST_NAME} 'cd /var/www/myapp && git pull origin master'
 
workflows:
    version: 2
    # build_and_deploy job:Job called first
    build_and_deploy:
        #Call build and deploy jobs
        jobs:
            - build
            - deploy:
                requires:
                    #Run the build job before the deploy job!
                    - build
                #Run the deploy job only if pushed to the master branch
                filters:
                    branches:
                        only: master

Problems and solutions that occurred

① Error due to the port not being open

ssh: connect to host ************* port 22: Connection timed out

【solution】 Edit the inbound of the EC2 security group as follows. Note) For security reasons, it is preferable to use an intermediate server.

↓

② Error due to mismatch of private key

(1) Execute the following command on EC2 to create a pem key (name it circleci-key etc. because it may conflict with other keys)

ssh-keygen -m pem

(2) Execute the following command in EC2 and copy the public key (key name.pub) created in (1) to authorized_keys.

cat ~/.ssh/circleci-key.pub >> authorized_keys

③ Execute the following command on EC2 to display the private key created in ①.

cat ~/.ssh/circleci-key

④ Set the displayed private key to CircleCI's SSH-Key (At this time, include ----- BEGIN RSA PRIVATE KEY ----- and ----- END RSA PRIVATE KEY -----)

Finally

In my case, this cleared the error, Please try it.

reference

[How to use CircleCI](https://suwaru.tokyo/%E3%80%90%E4%BD%BF%E3%81%84%E6%96%B9%E3%80%91circleci%E3%81%A8 % E3% 81% AF% EF% BC% 9Fec2% E3% 81% ABssh% E3% 81% 97% E3% 81% A6% E3% 83% 87% E3% 83% 97% E3% 83% AD% E3 % 82% A4% E8% 87% AA% E5% 8B% 95% E5% 8C% 96 /)