JIRA created: https://issues.apache.org/jira/browse/FELIX-4332
/Bengt 2013/11/28 Bengt Rodehav <[email protected]> > I've come up with easily reproducable errors using Karaf 2.3.3: > > - Install a fresh Karaf 2.3.3 > - Add the following line to etc/custom.properties: > felix.fileinstall.enableConfigSave = true > > Create a file etc/test.cfg with the following contents: > > a=$\\{var} > ab=${a}b > abc=${ab}c > > I expect this to be evaluated to: > a=$\{var} > ab=$\{var}b > abc=$\{var}bc > > But if I execute the Karaf command: > > config:list "(service.pid=test)" > > I get: > > ---------------------------------------------------------------- > Pid: test > BundleLocation: null > Properties: > service.pid = test > a = ${var} > abc = bc > felix.fileinstall.filename = > file:/C:/dev/Karaf/apache-karaf-2.3.3/etc/test.cfg > ab = b > > My interpretation of this is that the variable "a" has been correctly > evaluated. But, when evalutating the variable "ab" it seems that the > variable "a" is evaluated again despite the fact that it has already been > evaluated. FileInstall now looks for the value of a variable called "var" > which evalutes to an empty string because there is no such variable. > > The variable "abc" consequently evaluates to "bc" since the variable "ab" > has been evaluated to "b". > > To make it even worse, now change the first row in test.cfg to: > > a=$\\\\{var} > > We now get: > > ---------------------------------------------------------------- > Pid: test > BundleLocation: null > Properties: > service.pid = test > a = $\{var} > abc = ${var}bc > felix.fileinstall.filename = > file:/C:/dev/Karaf/apache-karaf-2.3.3/etc/test.cfg > ab = ${var}b > > Thus we get the same phenomenom. The variable "a" is evaluated differently > if it is evaluated on its own or as part of another expression. But, due to > having configured FileInstall to write back changes, the contents of the > test.cfg is now changed by FileInstall despite the fact that the > configuration has not changed at all. The contents of test.cfg is now: > > a=$\\\\{var} > ab=${a}b > abc = ${var}bc > > The "abc" variable has been altered. FileInstall has incorrectly > determined that its value has changed. > > This is clearly a bug. I will create a JIRA. > > /Bengt > > > > 2013/11/26 Bengt Rodehav <[email protected]> > >> I'm using Apache Karaf 2.3.3 which comes with FileInstall 3.2.6. I have >> set the felix.fileinstall.enableConfigSave property to true in order to >> have FileInstall write back configuration changes to the file. Normally all >> configuration changes are done by editing the configuration file but there >> is one property that I change programmatically using ConfigAdmin (an >> "enable" property to start/stop my service). I am dependent on that >> property being persisted in the configuration file which is why I set the >> enableConfigSave property to true. >> >> When configuring FileInstall to write back configuration changes to the >> configuration file, it is important that variables are not substituted for >> the evaluated value. This normally works since FileInstall evalutates the >> property in the configuration file and compares it with the configuration >> admin's value. If they are the same, the value in the configuration file is >> kept unchanged. >> >> However, when using the escape character this is broken. In my case I'm >> using Apache Camel underneath. When configuring routes via the config >> admin, I sometimes need to set a value to >> "${expression-to-be-evaluated-by-camel}". I therefore escape the "{" and >> "}" to stop FileInstall from trying to evaluate the expression. Like this: >> >> $\\{expression-to-be-evaluated-by-camel\\} >> >> This also normally works but not when I have an indirection. E g when >> specifying the following: >> >> a=$\\{var} >> ab=${a}b >> >> FileInstall will change the configuration file to: >> >> a=$\\{var} >> ab = ${var}b >> >> Note that the variable "ab" has now been expanded and written back to the >> configuration file even if neither of the variables "a" and "ab" have been >> changed. >> >> I think this is because FileInstall does the following: >> >> 1. Calculates the value of "a" to "$\{var} >> 2. Calculates the value of "b" to "${var}b >> >> Note that every evaluation will perform "unescaping". This means that an >> extra "unescaping" will be done for every indirection which fools >> FileInstall into thinking that the property has been changed. >> >> I'm not exactly sure how this should be fixed in FileInstall. One idea is >> to never "unescape" already evaluated variables. Actually I think this is >> probably what would fix this... >> >> Does anybody have any ideas about this? Should I create a JIRA? >> >> /Bengt >> >> >> >> >> >> >> >
