This is my setup:
I use AWS Batch that is running a custom Docker image
The startup.sh file is an entrypoint script that is reading the nth line of a text file and copying it from s3 into the docker.
For example, if the first line of the .txt file is 'Startup_00001/ Startup_000018 Startup_000019', the bash script reads this line, and uses a for loop to copy them over.
This is part of my bash script:
STARTUP_FILE_S3_URL=s3://cmtestbucke/Config/
Startup_FileNames=$(sed -n ${LINE}p file.txt)
for i in ${Startup_FileNames}
do
Startup_FileURL=${STARTUP_FILE_S3_URL}$i
echo $Startup_FileURL
aws s3 cp ${Startup_FileURL} /home/CM_Projects/ &
done
Here is the log output from aws:
s3://cmtestbucke/Config/Startup_000017
s3://cmtestbucke/Config/Startup_000018
s3://cmtestbucke/Config/Startup_000019
Completed 727 Bytes/727 Bytes (7.1 KiB/s) with 1 file(s) remaining download: s3://cmtestbucke/Config/Startup_000018 to Data/Config/Startup_000018
Completed 731 Bytes/731 Bytes (10.1 KiB/s) with 1 file(s) remaining download: s3://cmtestbucke/Config/Startup_000017 to Data/Config/Startup_000017
fatal error: *An error occurred (404) when calling the HeadObject operation: Key
"Config/Startup_000019 " does not exist.*
My s3 bucket certainly contains the object s3://cmtestbucke/Config/Startup_000019
I noticed this happens regardless of filenames. The last iteration always gives this error.
I tested this bash logic locally with the same aws commands. It copies all 3 files.
Can someone please help me figure out what is wrong here?
The problem was with EOL of the text file. It was set to Windows(CR LF). The docker image is running Ubuntu which caused the error. I changed the EOL to Unix(LF). The problem was solved.
I am trying to create my first bash script. The goal of this script is to check at what rate my public IP changes. It is a fairly straight forward script. First it checks if the new address is different from the old one. If so then it should update the old one to the new one and print out the date along with the new IP address.
At this point I have created a simple script in order to accomplish this. But I have two main problems.
First the script keeps on printing out the IP even tough it hasn't changed and I have updated the PREV_IP with the CUR_IP.
My second problem is that I want the output to direct to a file instead of outputting it into the terminal.
The interval is currently set to 1 second for test purposes. This will change to a higher interval in the final product.
#!/bin/bash
while true
PREV_IP=00
do
CUR_IP=$(curl https://ipinfo.io/ip)
if [ $PREV_IP != "$CUR_IP" ]; then
PREV_IP=$CUR_IP
"$(date)"
echo "$CUR_IP"
sleep 1
fi
done
I also get a really weird output. I have edited my public IP to xx.xxx.xxx.xxx:
Sat 20 Mar 09:45:29 CET 2021
xx.xxx.xxx.xxx
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:--
while true
PREV_IP=00
do
is the reason you are seeing ip each loop. It's the same as while true; PREV_IP=00; do. The exit status of true; PREV_IP=00 is the exit status of last command - the exit status of assignment is 0 (success) - so the loop will always execute. But PREV_IP will be reset to 00 each loop... This is a typo and you meant to set prev_ip once, before the loop starts.
"$(date)"
will try execute the output of date command, as a next command. So it will print:
$ "$(date)"
bash: sob, 20 mar 2021, 10:57:02 CET: command not found
And finally, to silence curl, read man curl first and then find out about -s. I use -sS so errors are also visible.
Do not use uppercase variables in your scripts. Prefer lower case variables. Check you scripts with http://shellcheck.net . Quote variable expansions.
I would sleep each loop. Your script could look like this:
#!/bin/bash
prev=""
while true; do
cur=$(curl -sS https://ipinfo.io/ip)
if [ "$prev" != "$cur" ]; then
prev="$cur"
echo "$(date) $cur"
fi
sleep 1
done
that I want the output to direct to a file instead of outputting it into the terminal.
Then research how redirection works in shell and how to use it. The simplest would be to redirect echo output.
echo "$(date) $cur" >> "a_file.txt"
The interval is currently set to 1 second for test purposes. This will change to a higher interval in the final product.
You are still limited with the time it takes to connect to https://ipinfo.io/ip. And from ipinfo.io documentation:
Free usage of our API is limited to 50,000 API requests per month.
And finally, I wrote a script where I tried to use many public services as I found ,get_ip_external for getting external ip address. You may take multiple public services for getting ipv4 address and choose a random/round-robin one so that rate-limiting don't kick that fast.
I am doing some basic piping of some simple raw code from github to terminal as shown here i.e.
curl https://raw.github.com/leachim6/hello-world/master/r/ruby.rb | ruby
When I try it, it doesn't produce "Hello World", but instead I just see
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- 0:00:01 --:--:-- 0
use
curl -sSL https://raw.github.com/leachim6/hello-world/master/r/ruby.rb | ruby
this should work
Update to explain
this URL is redirecting to
https://raw.githubusercontent.com/leachim6/hello-world/master/r/ruby.rb
so -L option was required to follow the redirection (-L, --location)
this option will make curl redo the request on the new place
sS to hide the progress bar and show errors if happened
to debug curl request you can use -v option which will make you see exactly what is happening
The problem
SNMPD is correctly delegating SNMP polling requests to another program but the response from that program is not valid. A manual run of the program with the same arguments is responding correctly.
The detail
I've installed the correct LSI raid drivers on a server and want to configure SNMP. As per the instructions, I've added the following to /etc/snmp/snmpd.conf to redirect SNMP polling requests with a given OID prefix to a program:
pass .1.3.6.1.4.1.3582 /usr/sbin/lsi_mrdsnmpmain
It doesn't work correctly for SNMP polling requests:
snmpget -v1 -c public localhost .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.1
I get the following response:
Error in packet
Reason: (noSuchName) There is no such variable name in this MIB.
Failed object: SNMPv2-SMI::enterprises.3582.5.1.4.2.1.2.1.32.1
What I've tried
SNMPD passes two arguments, -g and <oid> and expects a three line response <oid>, <data-type> and <data-value>.
If I manually run the following:
/usr/sbin/lsi_mrdsnmpmain -g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
I correctly get a correct three line response:
.1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
integer
30
This means that the pass command is working correctly and the /usr/sbin/lsi_mrdsnmpmain program is working correctly in this example
I tried replacing /usr/sbin/lsi_mrdsnmpmain with a bash script. The bash script delegates the call and logs the supplied arguments and output from the delegated call:
#!/bin/bash
echo "In: '$#" > /var/log/snmp-pass-test
RETURN=$(/usr/sbin/lsi_mrdsnmpmain $#)
echo "$RETURN"
echo "Out: '$RETURN'" >> /var/log/snmp-pass-test
And modified the pass command to redirect to the bash script. If I run the bash script manually /usr/sbin/snmp-pass-test -g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0 I get the correct three line response as I did when I ran /usr/sbin/lsi_mrdsnmpmain manually and I get the following logged:
In: '-g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
Out: '.1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
integer
30'
When I rerun the snmpget test, I get the same Error in packet... error and the bash script's logging shows that the captured delegated call output is empty:
In: '-g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
Out: ''
If I modify the bash script to only echo an empty line I also get the same Error in packet... message.
I've also tried ensuring that the environment variables that are present when I manually call /usr/sbin/lsi_mrdsnmpmain are the same for the bash script but I get the same empty output.
Finally, my questions
Why would the bash script behave differently in these two scenarios?
Is it likely that the problem that exists with the bash scripts is the same as originally noticed (manually running program has different output to SNMPD run program)?
Updates
eewanco's suggestions
What user is running the program in each scenario?
I added echo "$(whoami)" > /var/log/snmp-pass-test to the bash script and root was added to the logs
Maybe try executing it in cron
Adding the following to root's crontab and the correct three line response was logged:
* * * * * /usr/sbin/lsi_mrdsnmpmain -g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.1 >> /var/log/snmp-test-cron 2>&1
Grisha Levit's suggestion
Try logging the stderr
There aren't any errors logged
Checking /var/log/messages
When I run it via SNMPD, I get MegaRAID SNMP AGENT: Error in getting Shared Memory(lsi_mrdsnmpmain) logged. When I run it directly, I don't. I've done a bit of googling and I may need lm_sensors installed; I'll try this.
I installed lm_sensors & compat-libstdc++-33.i686 (the latter because it said it was a pre-requisite from the instructions and I was missing it), uninstalled and reinstalled the LSI drivers and am experiencing the same issue.
SELinux
I accidently stumbled upon a page about extending snmpd with scripts and it says to check the script has the right SELinux context. I ran grep AVC /var/log/audit/audit.log | grep snmp before and after running a snmpget and the following entry is added as a direct result from running snmpget:
type=AVC msg=audit(1485967641.075:271): avc: denied { unix_read unix_write } for pid=5552 comm="lsi_mrdsnmpmain" key=558265 scontext=system_u:system_r:snmpd_t:s0 tcontext=system_u:system_r:initrc_t:s0 tclass=shm
I'm now assuming that SELinux is causing the call to fail; I'll dig further...see answer for solution.
strace (eewanco's suggestion)
Try using strace with and without snmp and see if you can catch a system call failure or some additional hints
For completeness, I wanted to see if strace would have hinted that SELinux was denying. I had to remove the policy packages using semodule -r <policy-package-name> to reintroduce the problem then ran the following:
strace snmpget -v1 -c public localhost .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.1 >> strace.log 2>&1
The end of strace.log is as follows and unless I'm missing something, it doesn't seem to provide any hints:
...
sendmsg(3, {msg_name(16)={sa_family=AF_INET, sin_port=htons(161), sin_addr=inet_addr("127.0.0.1")}, msg_iov(1)= [{"0;\2\1\0\4\20public\240$\2\4I\264-m\2"..., 61}], msg_controllen=32, {cmsg_len=28, cmsg_level=SOL_IP, cmsg_type=, ...}, msg_flags=0}, MSG_DONTWAIT|MSG_NOSIGNAL) = 61
select(4, [3], NULL, NULL, {0, 999997}) = 1 (in [3], left {0, 998475})
brk(0xab9000) = 0xab9000
recvmsg(3, {msg_name(16)={sa_family=AF_INET, sin_port=htons(161), sin_addr=inet_addr("127.0.0.1")}, msg_iov(1)= [{"0;\2\1\0\4\20public\242$\2\4I\264-m\2"..., 65536}], msg_controllen=0, msg_flags=0}, MSG_DONTWAIT) = 61
write(2, "Error in packet\nReason: (noSuchN"..., 81Error in packet
Reason: (noSuchName) There is no such variable name in this MIB.
) = 81
write(2, "Failed object: ", 15Failed object: ) = 15
write(2, "SNMPv2-SMI::enterprises.3582.5.1"..., 48SNMPv2- SMI::enterprises.3582.5.1.4.2.1.2.1.32.1
) = 48
write(2, "\n", 1
) = 1
brk(0xaa9000) = 0xaa9000
close(3) = 0
exit_group(2) = ?
+++ exited with 2 +++
It was SELinux that was denying snmpd a delegated call to /usr/sbin/lsi_mrdsnmpmain (and probably beyond).
To identify it, I ran grep AVC /var/log/audit/audit.log and for each entry, I ran the following:
echo "<grepped-output>" | audit2allow -a -M <filename>
This creates a SELinux policy package that should allow the delegated call through. The package is then loaded using the following:
semodule -i <filename>.pp
I had to do this 5 times as there were different causes of denial (unix_read unix_write, associate, read write). I'll look to combine the modules into one.
Now when I run snmpget I get the correct delegated output:
SNMPv2-SMI::enterprises.3582.5.1.4.2.1.2.1.32.1 = INTEGER: 34
I am trying to download my Heroku backups to a folder.
Downloading to the current folder like this works:
curl -o latest.dump `heroku pg:backups public-url`
But when I tried adding a folders path to latest.dump it looks like this:
$ curl -o /db-bkups/latest.dump `heroku pg:backups public-url`
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 44318 0 0 0 0 0 0 --:--:-- 0:00:01 --:--:-- 0Warning: Failed to create the file
Warning: /db-bkups/latest.dump: No such file
Warning: or directory
36 44318 36 16384 0 0 9626 0 0:00:04 0:00:01 0:00:03 9626
curl: (23) Failed writing body (0 != 16384)
Ideally, I would like it be saved and downloaded like this:
/db-bkups/nov-1-2016/timestamp-db.dump
Where the folder nov-1-2016 is created dynamically when the cron is run, and the filename is the timestamp when the bkup was run.
You could try using the --create-dirs argument which was added in curl 7.10.3:
Here is an example that will create the directory hierarchy, (if it doesn't already exist), and will name the subdirectory you require renamed with the output of the datecommand:
curl -o /db-bkups/$(date +"%b-%d-%Y")/timestamp-db.dump --create-dirs http://www.w3schools.com/xml/simple.xml
The result is a file stored in a directory like so /db-bkups/Nov-04-2016/timestamp-db.dump.