I have a Tomcat 8 project that uses a datasource (see below)
<Resource auth="Container"
name="jdbc/JtmDS"
driverClassName="org.apache.derby.jdbc.EmbeddedDriver"
type="javax.sql.DataSource"
username="xfer"
password="xfer10"
url="jdbc:derby:/home/PUID/tm/control/JtmDB"
initialSize="25"
maxTotal="100"
maxIdle="30"
maxWaitMillis="10000"
removeAbandonedOnBorrow="true"
removeAbandonedTimeout="20" />
This works perfectly well.
However the url is a hard-coded path /home/PUID/tm/control/JtmDB
When this gets into production the PUID part of the path will differ across numerous systems.
I have an environment variable set export PUID=abcd
The rest of the application is able to use things like System.getenv( ) or ${env:PUID} as and where appropriate.
These all work fine.
My question is very simply: How can I make the PUID value in my context.xml a variable that can be read from an environment variable?
I finally discovered what I actually needed to do here.... Quite simple in the end.
I passed in a java parameter to Tomcat at runtime as shown below.
I added the following bits to setenv.sh
export PUID=abcd
JAVA_OPTS=-Dpuid=${PUID}
Then edited my context.xml as shown here
<Resource auth="Container"
name="jdbc/JtmDS"
driverClassName="org.apache.derby.jdbc.EmbeddedDriver"
type="javax.sql.DataSource"
username="xfer"
password="xfer10"
url="jdbc:derby:/home/${puid}/tm/control/JtmDB"
initialSize="25"
maxTotal="100"
maxIdle="30"
maxWaitMillis="10000"
removeAbandonedOnBorrow="true"
removeAbandonedTimeout="20" />
So now my Tomcat installation will read this and be able to use a different path for each different PUID.