YUM command failed with [Errno 14] curl#60 - “SSL certificate : unable to get local issuer certificate” in REDHAT

i'm getting an error [Errno 14] curl#60 - "SSL certificate problem: unable to get local issuer certificate" when i use yum command to install or update any package.

Ex:

yum install curl

then it gives and output like this

[root@dtetestmaster svradmin]# yum install curl
Loaded plugins: fastestmirror, product-id, search-disabled-repos, subscription-manager

This system is not registered with an entitlement server. You can use subscription-manager to register.

DialogRHSCLRepo                                                                                                          | 3.4 kB  00:00:00     
DialogRepo                                                                                                               | 3.5 kB  00:00:00     
https://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#60 - "SSL certificate problem: unable to get local issuer certificate"
Trying other mirror.
It was impossible to connect to the CentOS servers.
This could mean a connectivity issue in your environment, such as the requirement to configure a proxy,
or a transparent proxy that tampers with TLS security, or an incorrect system clock.
You can try to solve this issue by using the instructions on https://wiki.centos.org/yum-errors
If above article doesn't help to resolve this issue please use https://bugs.centos.org/.



 One of the configured repositories failed (Docker CE Stable - x86_64),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Run the command with the repository temporarily disabled
            yum --disablerepo=docker-ce-stable ...

     4. Disable the repository permanently, so yum won't use it by default. Yum
        will then just ignore the repository until you permanently enable it
        again or use --enablerepo for temporary usage:

            yum-config-manager --disable docker-ce-stable
        or
            subscription-manager repos --disable=docker-ce-stable

     5. Configure the failing repository to be skipped, if it is unavailable.
        Note that yum will try to contact the repo. when it runs most commands,
        so will have to try and fail each time (and thus. yum will be be much
        slower). If it is a very temporary problem though, this is often a nice
        compromise:

            yum-config-manager --save --setopt=docker-ce-stable.skip_if_unavailable=true

failure: repodata/repomd.xml from docker-ce-stable: [Errno 256] No more mirrors to try.
https://download.docker.com/linux/centos/7/x86_64/stable/repodata/repomd.xml: [Errno 14] curl#60 - "SSL certificate problem: unable to get local issuer certificate"

Please help to resolve this error, Thanks!

Solution 1:

This is directly from the Centos wiki listed in the error message

1. Validate the system can see things on the internet.

   ping google.com

2. This issue can also occur due to corruption of the local machine cache, try to clear cache on system:

   yum clean all

   rm -rf /var/cache/yum/*

3. If you have a proxy server, validate it is configured properly in /etc/yum.conf. Here is an example (your names, passwords, and port numbers will obviously be different).

   proxy=http://mystuff.mydomain.com:1234
   proxy_username=proxy-user
   proxy_password=proxy-password

4. Temporarily comment out the mirror= line in the the .repo file, then:

   yum clean all; yum makecache