Useful gfsh Shell Variables says gfsh>echo --string=${VARIABLE} could obtain the current value of the existing variable. But in my environment it couldn't.
e.g.:
echo --string=${SYS_USER} displayed ${SYS_USER}
gfsh>echo --string=$* could display a list of all gfsh shell variables and their current values in my environment(Apache Geode 1.5.0).
I encountered the same issue with Geode 1.6 and GemFire 9.x (multiple versions). EchoCommand.java has $* coded as a special case, but does not cover the other cases. I submitted JIRA GEODE-5531.
Related
We're developing several Lagom-based Scala micro-services. They are configured using variable replacement in application.conf, eg.
mysql = {
url = "jdbc:mysql://"${?ENV_MYSQL_DATABASE_URL}
During development, we set these variables as Java System Properties via a env.sbt file that calls System.setProperty("ENV_MYSQL_DATABASE_URL", url). This is working fine.
Now I want to deploy this in a container to my local Docker installation. We are using the SbtReactiveAppPlugin to build the Docker image from build.sbt and simply run sbt Docker/publishLocal. This works as expected, a Docker image is created and I can fire it up.
However, passing in environment variables using the standard docker or docker-compose mechanisms does not seem to work. While I can see that the environment variables are set correctly inside the Docker container (verified using env on a bash and also by doing log.debug("ENV_MYSQL_DATABASE_URL via env: " + sys.env("ENV_MYSQL_DATABASE_URL")) inside the service), they are not used by the application.conf and not available in the configuration system. The values are empty/unset (verified through configuration.getString("ENV_MYSQL_DATABASE_URL").toString() and the exceptions thrown by the mysql system and other systems).
The only way I've gotten it to work was by fudging this into the JAVA_OPTS via JAVA_OPTS=-D ENV_MYSQL_DATABASE_URL=..... However, this seems like a hack, and doesn't appear to scale very well with dozens of environment parameters.
Am I missing something, is there a way to easily use the environment variables inside the Lagom application and application.conf?
Thanks!
I've used Lightbend config to configure Lagom services via environment variables in docker containers for many years, so know that it can be done and has been pretty straightforward in my experience.
With that in mind, when you say that they're not used by application.conf, do you mean that they're unset? Note that unless you're passing a very specific option as a Java property, configuration.getString("ENV_MYSQL_DATABASE_URL") will not read from an environment variable, so checking that will not tell you anything about whether mysql.url is affected by the environment variable. configuration.getString("mysql.url") will give you a better idea of what's going on.
I suspect that in fact your Docker image is being built with the dev-mode properties hardcoded in, and since Java system properties take precedence over everything else, they're shadowing the environment variable.
You may find it useful to structure your application.conf along these lines:
mysql_database_url = "..." # Some reasonable default default for dev-mode
mysql_database_url = ${?ENV_MYSQL_DATABASE_URL}
mysql {
url = "jdbc://"${mysql_database_url}
}
In this case, you have a reasonable default for a developer (probably including in the docs some instructions for running MySQL in a way compatible with that configuration). The default can then be overridden via setting a Java property (e.g. JAVA_OPTS=-Dmysql_database_url) or by setting the ENV_MYSQL_DATABASE_URL environment variable.
While I agree with the answer provided by Levi Ramsey, I would suggest you to use typesafe's config to load the your config
Adding Property in Scala Environment Properties
val sysProps = System.getProperties
sysProps.setProperty("current.date.time", LocalDateTime.now().toString())
i'm able to save this property.
I tried accessing this property(current.date.time) in log4j.properties like below
log4j.appender.file.File=C:/Users/vsami/Desktop/Demo_${current.date.time}.log
log4j.appender.file.File=C:/Users/vsami/Desktop/Demo_${env:current.date.time}.log
Log file is getting generated in above location like Demo_.log, Expected :- Demo_2019/11/27T13:21:00.log
Above implementation is not helping me in accessing variable from environment properties and generate log file with expected naming convention.
JVM has properties that can be passed via -D parameter at VM boot. -Dprop=value.
These properties can be read via System.getProperties API call. See docs for more info.
Environment variables are not specified on JVM boot and managed independently from VM by your boot environment (it can be shell, bash etc). You cannot change environment variables in already running VM. These variables can be read via System.getenv()
$ is a look up operator in log4j and can be used to resolve env variables with env: prefix or Main Arguments Lookup with prefix main:.
You could use main:current.date.time and initialise your value as following
MainMapLookup.setMainArguments(Array("--current.date.time", LocalDateTime.now().toString()));
Make sure that MainMapLookup is called before logging is initialised.
I'm trying to modify the config of a running Wildfly (inside Docker) using the JBoss CLI. One thing I need to do is
data-source add --connection-url=jdbc:mysql://${DB_PORT_3306_TCP_ADDR}:3306/xplore (...)
I need the resulting config in standalone.xml to literally contain
<connection-url>jdbc:mysql://${DB_PORT_3306_TCP_ADDR}:3306/xplore</connection-url>
DB_PORT_3306_TCP_ADDR is a variable that will be resolved by Wildfly when it's rebooted. It does not exist when I'm CLI-ing.
The problem is that CLI attempts to resolve it (and fails) during my CLI session (instead of injecting it as a plain string), resulting in output like errors and even
<connection-url>$</connection-url>
I've tried to work around this by adding "..." and '...', escaping the $ to \$, removing the brackets, and defining a variable containing my string in the script and inserting that variable (still gets resolved). I've looked up the docs on this, and while there is a command resolve-expression(), there is no inverse, no setting for it, nothing. It doesn't seem possible to prevent the resolution from happening.
How can I insert an unresolved expression into my config via the CLI?
The answer was to issue this command:
data-source add --connection-url=jdbc:mysql://${DB_PORT_3306_TCP_ADDR:}:3306/xplore (...)
With a : after ADDR. This obviously solves the resolution error since it will now default to an empty value, and somehow it actually causes the string value itself to be written. It also turns out it wasn't the CLI that was resolving my variable, but the server itself.
The real solution though was to stop the session, modify the server settings and disable variable resolution entirely, then start a new session.
I have read the documentation concerning falling back to environment variables at https://github.com/typesafehub/config/blob/master/HOCON.md#substitution-fallback-to-environment-variables. My understanding was that it would pickup any envars. So for instance, if from the shell I was able to do echo $HOSTNAME and see a non-empty response then HOCON should do that as well.
In my application.conf I have a line
akka.remote.netty.tcp.hostname = ${HOSTNAME}
However, my app is not happy with this and fails to start with.
/conf/application.conf: 9: Could not resolve substitution to a value: ${HOSTNAME}
Is this a user issue? A shell issue? I am able to login as the user and echo $HOSTNAME
Tagging this scala and akka since that userbase probably has the most exposure to HOCON
The reason for HOCON not picking up the envar is that my app runs as a linux service (Centos 6.5) which clears away most environment variables.
See https://unix.stackexchange.com/questions/44370/how-to-make-unix-service-see-environment-variables for a relevant description of the issue
this is a shot in the dark, but are you using an older version of typesafe-config? maybe its a newer-ish feature? the feature seems to be advertised as you describe, but if you are pulling in typesafe-config as a transient dependency (say from akka), maybe you are getting an older version.
what happens if you remove the substitution in your .conf file (so parsing is successful) and then print out the contents of ConfigFactory.systemEnvironment()? for reference: http://typesafehub.github.io/config/latest/api/com/typesafe/config/ConfigFactory.html#systemEnvironment--
HOSTNAME isn't an environment variable. It's a bash internal variable. See https://superuser.com/questions/132489/hostname-environment-variable-on-linux for more details.
I have installed the postgresql module from Puppetforge.
How can I query Postgresql resources using ralsh ?
None of the following works:
# ralsh postgresql::db
# ralsh puppetlabs/postgresql::db
# ralsh puppetlabs-postgresql::db
I was hoping to use this to get a list of databases (including attributes such as character sets) and user names/passwords from the current system in a form that I can paste into a puppet manifest to recreate that setup on a different machine.
In principle, any puppet client gets the current state of your system from another program called Facter. You should create a custom Fact (a module of Facter), and then included into your puppet client. Afterwards, I think you could call this custom Fact from ralsh.
More information about creating a custom Fact can be found in here.
In creating your own Fact, you should execute your SQL query and then save the result into particular variable.