failed to link /usr/share/man/man1/java.1 -> /etc/alternatives/java.1: No such file or directory

Error : failed to link /usr/share/man/man1/java.1 -> /etc/alternatives/java.1: No such file or directory

I am trying to install a java rpm in a docker container via dockerfile. I got the above error while installing rpm.

The reason is its a small container that cause the error. A workaround for getting out of this error is to create a directory before the rpm installation in your dockerfile.

mkdir -p /usr/share/man/man1

This works for me :)

Get https://registry-1.docker.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)

Getting the following error in docker:

Get https://registry-1.docker.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)

Issue fix:

1. cd /etc/systemd/system/docker.service.d  (If not present, create this directory structure)

2. Create a file http-proxy.conf in that path and update the following

Environment="HTTP_PROXY=http://yourproxy.com:80/"

Environment="NO_PROXY=localhost,127.0.0.0/8,docker-registry.somecorporation.com"

3. systemctl daemon-reload

4. systemctl show --property Environment docker

Environment=HTTP_PROXY=http://yourproxy.com:80/

5. systemctl restart docker

This fixed my issue. I am using OEL7.5

How can I enable root ssh access in EC2

My requirement is, I need to disable the key authentication and I need to enable root ssh access to my AWS EC2 server.

How can I do that?

Login to your EC2 server with key authentication first
vim /etc/ssh/sshd_config
Disable - PermitRootLogin forced-commands-only and update the same with PermitRootLogin yes
Disable - #PermitEmptyPasswords no and update the same with PasswordAuthentication yes
/etc/init.d/sshd restart

Give root a good password.

Try to login with SSH and given root password.

Jenkins Error:ERROR: Error cloning remote repo 'origin'

In my Jenkins job, I am getting the following error

ERROR: Error cloning remote repo 'origin'
hudson.plugins.git.GitException: Could not init /home/ec2-user/local-jenkins/workspace/vpc_terraform
 at org.jenkinsci.plugins.gitclient.CliGitAPIImpl$5.execute(CliGitAPIImpl.java:772)
 at org.jenkinsci.plugins.gitclient.CliGitAPIImpl$2.execute(CliGitAPIImpl.java:564)
 at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler$1.call(RemoteGitImpl.java:153)
 at org.jenkinsci.plugins.gitclient.RemoteGitImpl$CommandInvocationHandler$1.call(RemoteGitImpl.java:146)
 at hudson.remoting.UserRequest.perform(UserRequest.java:212)
 at hudson.remoting.UserRequest.perform(UserRequest.java:54)
 at hudson.remoting.Request$2.run(Request.java:369)
 at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72)
 at java.util.concurrent.FutureTask.run(FutureTask.java:266)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
 at java.lang.Thread.run(Thread.java:748)

I was trying to checkout/download a repository from gitlab. I have given the repo name, credentials and branch.

Solution:

Go to the node where it is going to run (Slave node configuration)
Under Check Tool Locations under Node Properties 
Select Git and input the location of git (which git)
Save and reconnect the slave again.