WLST data source and unknown host - docker

Question

I'm using the online WLST script to configure the WebLogic server during Docker image build. Basically the docker image build starts up the WebLogic and executes the following script
import os
import time
import getopt
import sys
import re
# Deployment Information
domainname = os.environ.get('DOMAIN_NAME', 'base_domain')
domainhome = os.environ.get('DOMAIN_HOME', '/u01/oracle/user_projects/domains/' + domainname)
cluster_name = os.environ.get("CLUSTER_NAME", "DockerCluster")
admin_name = os.environ.get("ADMIN_NAME", "AdminServer")
connect(username,password,server_url)
edit()
print ""
print "================== DataSource ==================="
startEdit()
# Create Datasource
# ==================
cd('/')
cmo.createJDBCSystemResource(dsname)
cd('/JDBCSystemResources/' + dsname + '/JDBCResource/' + dsname)
cmo.setName(dsname)
cd('/JDBCSystemResources/' + dsname + '/JDBCResource/' + dsname)
cd('JDBCDataSourceParams/' + dsname)
set('JNDINames', jarray.array([String(dsjndiname)], String))
cd('/JDBCSystemResources/' + dsname + '/JDBCResource/' + dsname)
cd('JDBCDriverParams/' + dsname)
cmo.setDriverName(dsdriver)
cmo.setUrl(dsurl)
set('PasswordEncrypted', encrypt(dspassword))
print 'create JDBCDriverParams Properties'
cd('Properties/' + dsname)
cmo.createProperty('user')
cd('Properties/user')
cmo.setValue(dsusername)
print 'create JDBCConnectionPoolParams'
cd('/JDBCSystemResources/' + dsname + '/JDBCResource/' + dsname)
cd('JDBCConnectionPoolParams/' + dsname)
set('TestTableName','SQL SELECT 1 FROM DUAL')
# Assign
# ======
#assign('JDBCSystemResource', dsname, 'Target', admin_name)
#assign('JDBCSystemResource', dsname, 'Target', cluster_name)
cd('/SystemResources/' + dsname)
set('Targets',jarray.array([ObjectName('com.bea:Name=' + targetname + ',Type=' + targettype)], ObjectName))
# Update Domain, Close It, Exit
# ==========================
#save()
activate()
print ""
#disconnect()
exit()
The problem is, the database host doesn't exists at the build time, as it is the container name of another docker container in the docker-compose environment. With this script, setting the target on data source throws exception, as the host name couldn't be resolved, thus the activate call fails, as well as all the following WLST scripts which depends on the data source. Yet, I don't want to manually set the target after the whole environment is up and running. How do I avoid the exception in this case?

Answer 1

Set the inital and the minimum capacity of the datasource to 0, this allows activation without testing and should skip your error.