rpm spec
%post
%sysctl_apply openstack-keystone.conf
What is the meaning of sysctl_apply? Where can I find this document?
Lets expand it:
$ rpm --eval '%sysctl_apply foo'
/usr/lib/systemd/systemd-sysctl foo >/dev/null 2>&1 || :
Now see man systemd-sysctl for more informations and you will learn that is sets kernel parameters using sysctl.
For more informations and similar macros see: https://fedoraproject.org/wiki/Packaging:Guidelines#binfmt.d.2C_sysctl.d_and_tmpfiles.d
Related
When I use any command with sudo the environment variables are not there. For example after setting HTTP_PROXY the command wget works fine without sudo. However if I type sudo wget it says it can't bypass the proxy setting.
First you need to export HTTP_PROXY. Second, you need to read man sudo, and look at the -E flag. This works:
$ export HTTP_PROXY=foof
$ sudo -E bash -c 'echo $HTTP_PROXY'
Here is the quote from the man page:
-E, --preserve-env
Indicates to the security policy that the user wishes to preserve their
existing environment variables. The security policy may return an error
if the user does not have permission to preserve the environment.
The trick is to add environment variables to sudoers file via sudo visudo command and add these lines:
Defaults env_keep += "ftp_proxy http_proxy https_proxy no_proxy"
taken from ArchLinux wiki.
For Ubuntu 14, you need to specify in separate lines as it returns the errors for multi-variable lines:
Defaults env_keep += "http_proxy"
Defaults env_keep += "https_proxy"
Defaults env_keep += "HTTP_PROXY"
Defaults env_keep += "HTTPS_PROXY"
For individual variables you want to make available on a one off basis you can make it part of the command.
sudo http_proxy=$http_proxy wget "http://stackoverflow.com"
You can also combine the two env_keep statements in Ahmed Aswani's answer into a single statement like this:
Defaults env_keep += "http_proxy https_proxy"
You should also consider specifying env_keep for only a single command like this:
Defaults!/bin/[your_command] env_keep += "http_proxy https_proxy"
A simple wrapper function (or in-line for loop)
I came up with a unique solution because:
sudo -E "$#" was leaking variables that was causing problems for my command
sudo VAR1="$VAR1" ... VAR42="$VAR42" "$#" was long and ugly in my case
demo.sh
#!/bin/bash
function sudo_exports(){
eval sudo $(for x in $_EXPORTS; do printf '%q=%q ' "$x" "${!x}"; done;) "$#"
}
# create a test script to call as sudo
echo 'echo Forty-Two is $VAR42' > sudo_test.sh
chmod +x sudo_test.sh
export VAR42="The Answer to the Ultimate Question of Life, The Universe, and Everything."
export _EXPORTS="_EXPORTS VAR1 VAR2 VAR3 VAR4 VAR5 VAR6 VAR7 VAR8 VAR9 VAR10 VAR11 VAR12 VAR13 VAR14 VAR15 VAR16 VAR17 VAR18 VAR19 VAR20 VAR21 VAR22 VAR23 VAR24 VAR25 VAR26 VAR27 VAR28 VAR29 VAR30 VAR31 VAR32 VAR33 VAR34 VAR35 VAR36 VAR37 VAR38 VAR39 VAR40 VAR41 VAR42"
# clean function style
sudo_exports ./sudo_test.sh
# or just use the content of the function
eval sudo $(for x in $_EXPORTS; do printf '%q=%q ' "$x" "${!x}"; done;) ./sudo_test.sh
Result
$ ./demo.sh
Forty-Two is The Answer to the Ultimate Question of Life, The Universe, and Everything.
Forty-Two is The Answer to the Ultimate Question of Life, The Universe, and Everything.
How?
This is made possible by a feature of the bash builtin printf. The %q produces a shell quoted string. Unlike the parameter expansion in bash 4.4, this works in bash versions < 4.0
Add code snippets to /etc/sudoers.d
Don't know if this is available in all distros, but in Debian-based distros, there is a line at or near the tail of the /etc/sudoers file that includes the folder /etc/sudoers.d. Herein, one may add code "snippets" that modify sudo's configuration. Specifically, they allow control over all environment variables used in sudo.
As with /etc/sudoers, these "code snippets" should be edited using visudo. You can start by reading the README file, which is also a handy place for keeping any notes you care to make:
$ sudo visudo -f /etc/sudoers.d/README
# files for your snippets may be created/edited like so:
$ sudo visudo -f /etc/sudoers.d/20_mysnippets
Read the "Command Environment" section of 'man 5 sudoers'
Perhaps the most informative documentation on environment configuration in sudo is found in the Command environment section of man 5 sudoers. Here, we learn that a sudoers environment variables that are blocked by default may be "whitelisted" using the env_check or env_keep options; e.g.
Defaults env_keep += "http_proxy HTTP_PROXY"
Defaults env_keep += "https_proxy HTTPS_PROXY"
Defaults env_keep += "ftp_proxy FTP_PROXY"
And so, in the OP's case, we may "pass" the sudoer's environment variables as follows:
$ sudo visudo -f /etc/sudoers.d/10_myenvwlist
# opens the default editor for entry of the following lines:
Defaults env_keep += "http_proxy HTTP_PROXY"
Defaults env_keep += "https_proxy HTTPS_PROXY"
# and any others deemed useful/necessary
# Save the file, close the editor, and you are done!
Get your bearings from '# sudo -V'
The OP presumably discovered the missing environment variable in sudo by trial-and-error. However, it is possible to be proactive: A listing of all environment variables, and their allowed or denied status is available (and unique to each host) from the root prompt as follows:
# sudo -V
...
Environment variables to check for safety:
...
Environment variables to remove:
...
Environment variables to preserve:
...
Note that once an environment variable is "whitelisted" as above, it will appear in subsequent listings of sudo -V under the "preserve" listing.
If you have the need to keep the environment variables in a script you can put your command in a here document like this. Especially if you have lots of variables to set things look tidy this way.
# prepare a script e.g. for running maven
runmaven=/tmp/runmaven$$
# create the script with a here document
cat << EOF > $runmaven
#!/bin/bash
# run the maven clean with environment variables set
export ANT_HOME=/usr/share/ant
export MAKEFLAGS=-j4
mvn clean install
EOF
# make the script executable
chmod +x $runmaven
# run it
sudo $runmaven
# remove it or comment out to keep
rm $runmaven
OK, this might be a silly question. I've got the test.json file:
{
"timestamp": 1234567890,
"report": "AgeReport"
}
What I want to do is to extract timestamp and report values and store them in some env variables:
export $(cat test.json | jq -r '#sh "TIMESTAMP=\(.timestamp) REPORT=\(.report)"')
and the result is:
echo $TIMESTAMP $REPORT
1234567890 'AgeReport'
The problem is that those single quotes break other commands.
How can I get rid of those single quotes?
NOTE: I'm gonna leave the accepted answer as is, but see #Inian's answer for a better solution.
Why make it convoluted with using eval and have a quoting mess? Rather simply emit the variables by joining them with NULL (\u0000) and read it back in the shell environment
{
IFS= read -r -d '' TIMESTAMP
IFS= read -r -d '' REPORT
} < <(jq -r '(.timestamp|tostring) + "\u0000" + .report + "\u0000"' test.json)
This makes your parsing more robust by making the fields joined by NULL delimiter, which can't be part of your string sequence.
From the jq man-page, the #sh command converts its input to be
escaped suitable for use in a command-line for a POSIX shell.
So, rather than attempting to splice the output of jq into the shell's export command which would require carefully removing some quoting, you can generate the entire commandline inside jq, and then execute it with eval:
eval "$(
cat test.json |\
jq -r '#sh "export TIMESTAMP=\(.timestamp) REPORT=\(.report)"'
)"
is there any lvm.conf editor?
I'm trying to set global_filter, use_lvmtad and some other options, currently using sed:
sed -i /etc/lvm/lvm.conf \
-e "s/use_lvmetad = 1/use_lvmetad = 0/" \
-e "/^ *[^#] *global_filter/d" \
-e "/^devices {/a\ global_filter = [ \"r|/dev/drbd.*|\", \"r|/dev/dm-.*|\", \"r|/dev/zd.*|\" ]"
but I don't like this too much, is there any better way?
I found only lvmconfig tool, but it can only display certain configuration sections, and can't edit them.
If you using Ubuntu variant then you can use the LVM GUI to configure and manage the LVM. Refer this link
It seems that augtool is exactly what I was looking for.
These two packages should be enough to proper processing lvm.conf file:
apt install augeas-tools augeas-lenses
Example usage:
augtool print /files/etc/lvm/lvm.conf
And you should get the whole parse tree on stdout.
If the parser fails you won’t get any output, print the error message using:
augtool print /files/etc/lvm/lvm.conf/error
The augtool equivalent for the sed command from the original question:
augtool -s <<EOT
set /files/etc/lvm/lvm.conf/global/dict/use_lvmetad/int "0"
rm /files/etc/lvm/lvm.conf/devices/dict/global_filter
set /files/etc/lvm/lvm.conf/devices/dict/global_filter/list/0/str "r|^/dev/drbd.*|"
set /files/etc/lvm/lvm.conf/devices/dict/global_filter/list/1/str "r|/dev/dm-.*|"
set /files/etc/lvm/lvm.conf/devices/dict/global_filter/list/2/str "r|/dev/zd.*|"
EOT
I am using weka 3.6.13 and trying to use a model to classify data:
java -cp weka-stable-3.6.13.jar weka.classifiers.Evaluation weka.classifiers.trees.RandomForest -l Parking.model -t Data_features_class_ques-2.arff
java.lang.Exception: training and test set are not compatible
though the model works when we use the GUI, through Explorer->Claasify ->Supplied test set and load the arff file->right click on result list and load model-> again right click -> re-evaluate model on current data set...
Any pointers please help.
If your data contains "String" features then first use StringToWordVector in batch mode i.e. for both data set in single command (command 1) then use command 2 and command 3.
Command 1.
java weka.filters.unsupervised.attribute.StringToWordVector -b -R first-last -i training.arff -o training_s2w.arff -r test.arff -s test_s2w.arff
Command 2.
java weka.classifiers.trees.RandomForest -t training_s2w.arff -d model.model
Command 3.
java weka.classifiers.trees.RandomForest -T test_s2w.arff -l model.model -p 0 > result.txt
PS: add path for weka.jar accordingly.
So I'm using weka 3.7.11 in a Windows machine (and runnings bash scripts with cygwin), and I found an inconsistency regarding the AODE classifier (which in this version of weka, comes from an add-on package).
Using Averaged N-Dependencies Estimators from the GUI, I get the following configuration (from an example that worked alright in the Weka Explorer):
weka.classifiers.meta.FilteredClassifier -F "weka.filters.unsupervised.attribute.Discretize -F -B 10 -M -1.0 -R first-last" -W weka.classifiers.bayes.AveragedNDependenceEstimators.A1DE -- -F 1 -M 1.0 -S
So I modified this to get the following command in my bash script:
java -Xmx60G -cp "C:\work\weka-3.7.jar;C:\Users\Oracle\wekafiles\packages\AnDE\AnDE.jar" weka.classifiers.meta.FilteredClassifier \
-t train_2.arff -T train_1.arff \
-classifications "weka.classifiers.evaluation.output.prediction.CSV -distribution -p 1 -file predictions_final_multi.csv -suppress" \
-threshold-file umbral_multi.csv \
-F "weka.filters.unsupervised.attribute.Discretize -F -B 10 -M -1.0 -R first-last" \
-W weka.classifiers.bayes.AveragedNDependenceEstimators.A1DE -- -F 1 -M 1.0 -S
But this gives me the error:
Weka exception: No value given for -S option.
Which is weird, since this was not a problem with the GUI. In the GUI, the Information box says that -S it's just a flag ("Subsumption Resolution can be achieved by using -S option"), so it shouldn't expect any number at all, which is consistent with what I got using the Explorer.
So then, what's the deal with the -S option when using the command line? Looking at the error text given by weka, I found this:
Options specific to classifier weka.classifiers.bayes.AveragedNDependenceEstimators.A1DE:
-D
Output debugging information
-F <int>
Impose a frequency limit for superParents (default is 1)
-M <double>
Specify a weight to use with m-estimate (default is 1)
-S <int>
Specify a critical value for specialization-generalilzation SR (default is 100)
-W
Specify if to use weighted AODE
So it seems that this class works in two different ways, depending on which method I use (GUI vs. Command Line).
The solution I found, at least for the meantime, was to write -S 100 on my script. Is this really the same as just putting -S in the GUI?
Thanks in advance.
JM
I've had a play with this Classifier, and can confirm that what you are experiencing on your end is consistent with what I have here. From the GUI, the -S Option (subsumption Resolution) requires no parameters while the Command Prompt does (specialization-generalization SR).
They don't sound like the same parameter, so you may need to raise this issue with the developer of the third party package if you would like to know more information on these parameters. You can find this information from the Tools -> Package Manager -> AnDE, which will point you to the contacts for the library.