[ambari-2.7.3] Ambari writes Empty baseurl values written to Repo Files when using a local repository causing stack installation failure

Problem Statement : when using a local repository, installation fails due to empty baseurls being written to the Ambari repository (even though local repository baseurl values were provided). The installation fails with below error :

stderr:
Traceback (most recent call last):
File "/var/lib/ambari-agent/cache/stack-hooks/before-INSTALL/scripts/hook.py", line 37, in <module>
BeforeInstallHook().execute()
File "/usr/lib/ambari-agent/lib/resource_management/libraries/script/script.py", line 352, in execute
method(env)
File "/var/lib/ambari-agent/cache/stack-hooks/before-INSTALL/scripts/hook.py", line 33, in hook
install_packages()
File "/var/lib/ambari-agent/cache/stack-hooks/before-INSTALL/scripts/shared_initialization.py", line 37, in install_packages
retry_count=params.agent_stack_retry_count)
File "/usr/lib/ambari-agent/lib/resource_management/core/base.py", line 166, in __init__
self.env.run()
File "/usr/lib/ambari-agent/lib/resource_management/core/environment.py", line 160, in run
self.run_action(resource, action)
File "/usr/lib/ambari-agent/lib/resource_management/core/environment.py", line 124, in run_action
provider_action()
File "/usr/lib/ambari-agent/lib/resource_management/core/providers/packaging.py", line 30, in action_install
self._pkg_manager.install_package(package_name, self.__create_context())
File "/usr/lib/ambari-agent/lib/ambari_commons/repo_manager/yum_manager.py", line 219, in install_package
shell.repository_manager_executor(cmd, self.properties, context)
File "/usr/lib/ambari-agent/lib/ambari_commons/shell.py", line 753, in repository_manager_executor
raise RuntimeError(message)
RuntimeError: Failed to execute command '/usr/bin/yum -y install hdp-select', exited with code '1', message: 'Repository InstallMedia is listed more than once in the configuration

One of the configured repositories failed (Unknown),
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=<repoid> ...

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 <repoid>

or
subscription-manager repos --disable=<repoid>

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=<repoid>.skip_if_unavailable=true
Cannot find a valid baseurl for repo: HDP-3.1-repo-1
'
Command aborted. Reason: 'Server considered task failed and automatically aborted it'
stdout:

We can See that Ambari UI shows the empty baseURL in review step :

It also sends the empty Repo version while deploy stage

Root cause : https://issues.apache.org/jira/browse/AMBARI-25069

Workaround :

This is a Javascript bug in ambari that happens when using local repository and there is no internet access to cluster

to workaround this

Steps

1) go to /usr/lib/ambari-server/web/javascipts

cd /usr/lib/ambari-server/web/javascripts

2) take backup of app.js

cp app.js app.js_backup

3) edit the app.js

find out the line(39892) : onNetworkIssuesExist: function () {

Change the line from :

/**
* Use Local Repo if some network issues exist
*/
onNetworkIssuesExist: function () {
if (this.get('networkIssuesExist')) {
this.get('content.stacks').forEach(function (stack) {
stack.setProperties({
usePublicRepo: false,
useLocalRepo: true
});
stack.cleanReposBaseUrls();
});
}
}.observes('networkIssuesExist'),

to

/**
* Use Local Repo if some network issues exist
*/
onNetworkIssuesExist: function () {
if (this.get('networkIssuesExist')) {
this.get('content.stacks').forEach(function (stack) {
if(stack.get('useLocalRepo') != true){
stack.setProperties({
usePublicRepo: false,
useLocalRepo: true
});
stack.cleanReposBaseUrls();
}
});
}
}.observes('networkIssuesExist'),

as per : https://github.com/apache/ambari/pull/2743/files

Later as you have already deployed the cluster we need to reset the cluster (Caution : this will erase all the configs you have created previously in Step6 and also the Hosts and services you have selected need to select again )

Command :

ambari-server reset

And hard reload the page and start the create cluster wizard again.

Incase you have already at Step 9 and cannot proceed with ambari-server reset (as it invovles lots of Configs being added again , the below steps are for you )

Preqrequesties : The cluster now is in Deployment step(step 9 ) and you have only retry button to press

steps

1) Stop ambari-server

2) login to Database

3) use the below command to list out all the contents in repo_definition table :

select * from repo_definition;

4) you can see the base_url will be empty for the all the Rows in the table

5) Correct the base_url for every rows and update it using the command :

update repo_definition set base_url='<YOUR BASE URL>' where id=<THE CORESPONDING ID>;

for ex :

update repo_definition set base_url='http://asnaik.example.com/localrepo/HDP-3.1' where id=9;

6) after correcting all the base_url columns in repo_definition table and also delete the empty repos created by ambari from location /etc/yum.repos.d

7) start ambari, Login to UI and press retry button, The Installation will work as smooth as it can be.

Hope this helps.