CHANVICHEKA OUK | VIC

My co-worker executed a script I wrote for automating a few thing from our day-to-day work so our work life is easier. My co-worker DM’ed me via Slack that there was an error and it returned as “no se encontro la orden”. I never seen an error like that in Linux before. My first thought that it must be French as it sounds like French but turned out it is Spanish after I google translated it. It means “Command not found” and once I understand that then it is easier to pinpoint what went wrong with the script in my co-worker’s environment. And we got it resolved.

I am bilingual myself and also knew a little Japanese since I learned it for 3 years while pursuing my Undergraduate degree in Computer Science. Also I am just recently interested in learning Spanish as well.

I just helped a co-worker regarding this particular task where she wants to switch her network interface from manual static IP to automatic IP by dhcp in a linux client using command line since it does not have x desktop so I quickly wrote following script

you can find your interface name quickly by executing nmcli dev status at the terminal

switchStaticToDHCP.sh

requires passing by one argument which is your network interface name.

!/bin/bash
 nmcli con mod $1 ipv4.method auto
 nmcli con mod $1 ipv4.gateway ""
 nmcli con mod $1 ipv4.address ""
 nmcli con down $1
 nmcli con up $1
 dhclient $1

switchStaticToDHCP.sh Your_Network_Interface_Name

eg: bash switchStaticToDHCP.sh enp0s3

switchDHCPToStatic.sh

requires passing by 3 arguments – your network interface name, static ip address, & default gateway ip address.

!/bin/bash
 nmcli con mod $1 ipv4.method manual
 nmcli con mod $1 ipv4.addresses $2/24
 nmcli con mod $1 ipv4.gateway $3
 nmcli con down $1
 nmcli con up $1

swtichDHCPToStatic.sh Your_Network_Interface_Name IP_Address Default_Gateway

eg: bash switchDHCPToStatic.sh enp0s3 192.168.1.168 192.168.1.254

sometimes we do not want to pay for the Certificate authority – CA to issue a real certificate or for development, we just want to use a self sign cert that we signed and manually trusted it for testing https traffic just for development environment.

In Windows, we can just click on the self sign cert and it prompts us to where we want to store it which usually should be stored in Trusted Root Authority store.

But where is it in Linux and especially for mono? also I am not going to cover self sign cert for IIS server creation here in this post and I assume you already know how to do it. if you go to IIS manager (inetmgr) you should be able to create it there.

I wrote a bash script here where it will download your IIS self signed cert from your IIS Server in pem format and then merge it with existing certificate bundle – tls-ca-bundle.pem. Then sync the newly merged cert list to mono store – Trust store

registerIISServerCertSelfSignForMono.sh

#!/bin/bash
echo "Server:Port = $1";

### Download IIS self sign cert in pem format from given server:port
openssl s_client -showcerts -verify 5 -connect $1 < /dev/null | awk '/BEGIN/,/END/{ if(/BEGIN/) out="IISSelfSignCert.pem"; print >out}'

TEMPDIR=/etc/pki/ca-trust/source/temp

### Cleaning up our temp directory
rm -rf $TEMPDIR
mkdir -p $TEMPDIR

### copy our IIS Server self sign cert pem to our temp directory
cp IISSelfSignCert.pem $TEMPDIR

### Merge our IIS self sign cert pem to existing tls ca bundle cert pem
cp /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem $TEMPDIR/MergedCertList.pem

echo -e "\n# $f added for IIS Server Self Sign Cert" >> $TEMPDIR/MergedCertList.pem
cat $TEMPDIR/IISSelfSignCert.pem >> $TEMPDIR/MergedCertList.pem

cat $TEMPDIR/MergedCertList.pem

#now sync with Mono store, Trust store
cert-sync $TEMPDIR/MergedCertList.pem

Execute it at the terminal:

$ registerIISServerCertSelfSignForMono.sh yourServerName:Port

eg:

$ registerIISServerCertSelfSignForMono.sh www.vic-llc.org:443