Download Wrapper Script
Charlyn Scifres
The Wrapper shell script and batch file reside in the root directory of a single or multi-project Gradle build. You will need to reference the correct path to those files in case you want to execute the build from a subproject directory e.g. ../../gradlew tasks.
The better and recommended option is to run the wrapper task and provide the target Gradle version as described in Adding the Gradle Wrapper.Using the wrapper task ensures that any optimizations made to the Wrapper shell script or batch file with that specific Gradle version are applied to the project.
Note that running the wrapper task once will update gradle-wrapper.properties only, but leave the wrapper itself in gradle-wrapper.jar untouched.This is usually fine as new versions of Gradle can be run even with older wrapper files.
The Wrapper task fails if gradle-wrapper.properties contains distributionSha256Sum, but the task configuration does not define a sum.Executing the Wrapper task preserves the distributionSha256Sum configuration when the Gradle version does not change.
Lambda provides language-specific environment variables that you can set to add options and tools to the runtime. Lambda also provides wrapper scripts, which allow Lambda to delegate the runtime startup to your script. You can create a wrapper script to customize the runtime startup behavior.
You can create a wrapper script to customize the runtime startup behavior of your Lambda function. A wrapper script enables you to set configuration parameters that cannot be set through language-specific environment variables.
When you use a wrapper script for your function, Lambda starts the runtime using your script. Lambda sends to your script the path to the interpreter and all of the original arguments for the standard runtime startup. Your script can extend or transform the startup behavior of the program. For example, the script can inject and alter arguments, set environment variables, or capture metrics, errors, and other diagnostic information.
In the following example, you create a wrapper script to start the Python interpreter with the -X importtime option. When you run the function, Lambda generates a log entry to show the duration of the import time for each import.
Try something similar for the security flag! See if your solution is similar to mine at the end of this tutorial when I post the entire script. Hint: you probably will want to use some global variable that you can change to fit into the yum check-update command that will be used later.
Basically, this puts the command output (of yum check-update) into an array (updateArr). Notice the reference to a CMD variable, which is another hint as to what you can do with the security argument from the beginning of the script.
So what do you think? Is it cool knowing that you are so confined to the default plugins that the ITL and 3rd parties provide? You can make your own check scripts now! All you have to do now is to call the script from Icinga.
I monitor a lot with the powershell script monitor components. Some times I have the same powershell script in an application more than 10 times. So if I want to change something in the script I have to go to the template and change the same lines in each of the component.
jm_sysadmin I tried this but another problem occurred. If I use dot sourcing all parameters are passed as an array to the called script. This means all passed parameters are stored in an array in $args[0]. So if I want to access the agruments in the called script I have to access them like $args[0][0] or $args[0][1] and so on.
i had a problem. I have a debian linux machine here with an APC ups connected via usb cable running the lovely, small and simple apcupsd. Also another PC (running Windows) is connected to the same ups, so i installed apcupsd on windows too and connected it to the apcupsd on the linux machine, fine. Then i needed an additional NUT server so i can hook up my Synology NAS also to the same ups. But, trying to install the complicated nut server beside apcupsd on the same linux machine was a pain. So, i wrote this little script that emulates a nut-server and gets the values from apcupsd/apcaccess.
Instead, armed with the knowledge about wrapper scripts, let us write a Node.js script to do that for us. We could then execute that script as a part of the wrapper script logic giving us confidence that the S3 data will be there for the handler to consume it before its invocation.
Take note of the environment variables. Since the environment variables specified for the AWS Lambda function are available in the Init phase, they are also available to us in the wrapper scripts and every binary or script they invoke.
The second step is to write the wrapper script itself. As I eluded earlier, its primary purpose is to provide additional parameters to the runtime of your choice, but in our case, the script will be invoking the Node.js script from above.
Firstly let us tackle the wrapper script deployment. Wrapper scripts are deployed as layers. The wrapper script and an AWS Lambda handler connect through a particular environment variable. More on that when during the handler configuration.
By specifying the AWS_LAMBDA_EXEC_WRAPPER environment variable, you tell the AWS Lambda runtime where the wrapper script location. Please note that contents of AWS Lambda layers are unpacked into the /opt directory.
Apart from the limit of having a maximum of ten seconds for the Init phase, the most notable thing to consider is that the wrapper script is only invoked on AWS Lambda cold start. This makes it an ideal solution for fetching configuration data or performing static compute tasks, but do not expect to build a free API with this method (If you manage to do that, please let me know).
I'm not sure why this is happening, so as a last resort I'm posting it here to see if anyone can help me out and point out what's going on here. To reiterate, starting/stopping/restarting elasticsearch from the wrapper directly works just fine with no problems, but with systemd, it doesn't work.
The easiest way to setup the Maven Wrapper for your project is to use theMaven Wrapper Plugin with its provided wrapper goal. To add or update allthe necessary Maven Wrapper files to your project execute the following command:
A normal Maven build will be executed, with the one important change that if theuser doesn't have the necessary version of Maven specified in.mvn/wrapper/maven-wrapper.properties it will be downloaded for the userfirst, installed and then used.
In terms of Apache Maven versions itself, the wrapper should work with any Maven3.x version and it defaults to the release used when setting up the wrapper. We do NOTplan to support the deprecated, EOL'ed Maven 2.x.
By default, the Maven Wrapper JAR archive is added to the using project as smallbinary file .mvn/wrapper/maven-wrapper.jar. It is used to bootstrap thedownload and invocation of Maven from the wrapper shell scripts.
Another type is the lite implementation of mvnw/mvnw.cmd scripts which download the maven directlyvia wget or curl on *nix, or PowerShell on Windows, then call the original mvn/mvn.cmdscripts of the downloaded maven distribution.This type does not use maven-wrapper.jar nor MavenWrapperDownloader.java, only the wrapper scripts are required.
If the JAR is not found to be available by the scripts they will attempt todownload the file from the URL specified in.mvn/wrapper/maven-wrapper.properties under wrapperUrl and put it in place.The download is attempted via curl, wget and, as last resort, by compiling the.mvn/wrapper/MavenWrapperDownloader.java file and executing the resultingclass.
This is a feature of Maven itself and the wrapper just happens to take it intoaccount. Simply set MAVEN_USER_HOME to the desired path and the wrapper usesit as the base of the Maven distro installation.
To avoid supply-chain-attacks by downloading a corrupted artifact, itis possible to specify checksums for both the maven-wrapper.jar andthe downloaded distribution. To apply verification, add the expectedfile's SHA-256 sum in hex notation, using only small caps, tomaven-wrapper.properties. The property for validating themaven-wrapper.jar file is named wrapperSha256Sum whereas thedistribution file property is named distributionSha256Sum.
This tutorial is intended to do two things: to expand on the Cron Troubleshooting article; and to give an overview of a simple scripting concept that uses the creation of a file as a flag to signify something is running. This is primarily useful when you need to run something continuously, but not more than one copy at a time. You can create a file as a flag to check if a job is already running, , and in turn, check for that flag before taking further action.
The direct application of this is when you have a cron job that runs every minute, or every few minutes. With a rapidly repeating cron, if the previous job takes any longer than the scheduled time, these tasks can pile up causing load on the server, or exacerbating other issues. To avoid this, a simple script can be set up in the crontab (in place of the intended cron task). When the cron is run, it only runs the actual task if there is not a competing process already running.
A cron wrapper is used when you have a cron job that needs to run back to back but needs to not step on itself. This is good for tasks that you want to setup to run continuously. Jobs that should be run anywhere between every minute and every five minutes should be utilizing a wrapper like this.
The reason this is called a cron wrapper is that it is a script that wraps around the cron job, and checks if another instance of the cron is already running. If there is another copy running, the wrapper will make the cron skip this run, and wait until the next run to check again. There are a few ways that the cron wrappers ensures no overlap.
A straightforward method is to use what is called a lockfile. The cron wrapper checks if the lockfile (any file with a specific name/location) exists at the start of the run. If the lockfile is missing, the script creates that file and continues. The creation of the lockfile signals the start of the cron job. When the cron job completes the wrapper script then removes the lock file.
760c119bf3