VirtualTam's bookmarks

1. AWS | Enable Enhanced Networking with Elastic Network Adapters for vintage OS AMIs 2019-09-17

   tags: chroot, cloud/aws, linux, linux/debian, linux/kernel, virtualization, xen

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   Paravirtual (PV) to Hardware Virtual Machine (HVM):

   • https://stackoverflow.com/questions/24330721/amazon-ec2-how-to-convert-an-existing-pv-ami-to-hvm

   ENA support:

   • https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/enhanced-networking-ena.html
   • https://forums.aws.amazon.com/thread.jspa?threadID=166135
   • https://aws.amazon.com/premiumsupport/knowledge-center/boot-error-linux-m5-c5/
   • https://bugs.centos.org/view.php?id=14107
   • https://ygrene.tech/how-to-enable-ena-support-for-aws-amis-in-5-steps-and-make-your-bamboo-remote-jobs-really-fast-f2a4254a9955

   Build Debian AMIs from scratch:

   • https://bootstrap-vz.readthedocs.io/en/master/
   • https://github.com/andsens/bootstrap-vz
   • https://www.slideshare.net/JamesBromberger/debian-cloud-building-the-debian-amis
   • https://blog.james.rcpt.to/2012/12/06/official-debian-images-on-amazon-web-services-ec2/

   Squeeze:

   • https://lists.debian.org/debian-cloud/2013/02/msg00023.html

   Wheezy:

   • https://lists.debian.org/debian-cloud/2014/10/msg00009.html
   • https://lists.debian.org/debian-cloud/2014/11/msg00000.html

   Boot to chroot:

   • https://unix.stackexchange.com/questions/85714/boot-into-a-chroot
   • https://wiki.debian.org/chroot
   • https://wiki.debian.org/Debootstrap
   • https://superuser.com/questions/384437/booting-linux-system-from-chroot-is-there-a-better-way-to-do-this/384457#384457
   • https://github.com/lemonsqueeze/boot-chroot
2. iptables 2018-07-04

   tags: linux, linux/iptables, network, network/firewall, network/router, sysadmin

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   Documentation:

   • https://www.netfilter.org/documentation/index.html
   • https://www.netfilter.org/documentation/HOWTO//netfilter-hacking-HOWTO.html
   • https://www.netfilter.org/documentation/HOWTO//networking-concepts-HOWTO.html
   • https://www.netfilter.org/documentation/HOWTO//NAT-HOWTO.html
   • https://www.netfilter.org/documentation/HOWTO//packet-filtering-HOWTO.html
     • https://www.netfilter.org/documentation/HOWTO//packet-filtering-HOWTO-6.html
     • https://www.netfilter.org/documentation/HOWTO//packet-filtering-HOWTO-7.html

   Articles:

   • https://www.digitalocean.com/community/tutorials/how-the-iptables-firewall-works
   • https://www.digitalocean.com/community/tutorials/how-to-list-and-delete-iptables-firewall-rules
   • https://www.digitalocean.com/community/tutorials/iptables-essentials-common-firewall-rules-and-commands
   • https://www.digitalocean.com/community/tutorials/a-deep-dive-into-iptables-and-netfilter-architecture
   • https://www.digitalocean.com/community/tutorials/how-to-choose-an-effective-firewall-policy-to-secure-your-servers

   How-tos:

   • https://wiki.centos.org/HowTos/Network/IPTables
   • https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-using-iptables-on-ubuntu-14-04

   Routing:

   • https://www.frozentux.net/iptables-tutorial/iptables-tutorial.html
   • https://www.frozentux.net/iptables-tutorial/images/tables_traverse.jpg
   • https://www.frozentux.net/iptables-tutorial/images/table_subtraverse.jpg
   • https://upload.wikimedia.org/wikipedia/commons/3/37/Netfilter-packet-flow.svg

   RHEL Documentation:

   • https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/security_guide/sect-security_guide-firewalls-common_iptables_filtering
   • https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/security_guide/sect-security_guide-firewalls-forward_and_nat_rules
   • https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/security_guide/sect-security_guide-firewalls-malicious_software_and_spoofed_ip_addresses
   • https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/security_guide/sect-security_guide-firewalls-iptables_and_connection_tracking
   • https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/security_guide/sect-security_guide-iptables
   • https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/security_guide/sec-setting_and_controlling_ip_sets_using_iptables
3. OpenVPN-install: Set up your own OpenVPN server on Debian, Ubuntu, Fedora CentOS, and Arch Linux 2018-05-24

   tags: linux, network, network/vpn, security

   [ permalink ]

   • https://angristan.fr/installer-facilement-serveur-openvpn-debian-ubuntu-centos/
   • https://github.com/Nyr/openvpn-install
4. Centos/RHEL 7 - Fix LVM boot issues after migration from ESXi to VirtualBox 2018-04-20

   tags: boot, bootloader/grub, filesystem, filesystem/lvm, fstab, linux, linux/centos, linux/kernel, linux/red-hat

   [ permalink ]

   Here are the steps I used to migrate a CentOS 7 VM from (presumably?) an ESXi server, to a local VirtualBox environment.

   The LVM volumes were not detected at boot, and after the boot timeout, the OS fell back to the Dracut emergency shell.

   • get a CentOS minimal installation CD
   • check the VM's resources and peripherals:
     • ensure there are no floppy drives (!)
     • setup CPU and RAM resources
     • check virtual drives
     • add an SCSI optical drive if needed
   • optional: convert the virtual drive images from VMDK to VDI
   • mount the CentOS installation disc
   • boot on the installation disc:
     • select "Troubleshooting", then "Rescue"
     • let the rescue utility detect filesystems and mountpoints
   • $ chroot to the detected environment
   • backup files:
     • /etc/fstab
     • /boot/grub/grub.cfg
   • under /boot, backup the initrd and initramfs for the current configuration (these will be overwritten)
   • compare the current /etc/fstab with the output of $ lsblk and $ blkid
   • if needed, manually edit /etc/fstab to use the appropriate block device UUIDs, identifiers and mountpoints
   • regenerate GRUB configuration:
     • $ grub2-mkconfig -o /boot/grub2/grub.cfg
   • if needed, reinstall GRUB:
     • $ grub-install /dev/sda
   • rebuild initrd:
     • $ mkinitrd --force /boot/<initrd_image> <kernel_version>
   • rebuild initramfs:
     • $ dracut --force <kernel_version>
   • exit the chroot
   • unmount the installation disc
   • reboot
   • optional but highly recommended: cross your fingers
   • ...
   • profit!
5. Docker - FreeIPA 2018-04-05

   tags: linux, linux/centos, linux/container/docker, network/ldap, security/authentication, user

   [ permalink ]

   • https://github.com/freeipa/freeipa-container
   • https://hub.docker.com/r/freeipa/freeipa-server/
   • https://www.adelton.com/docs/docker/complex-application-in-container
   • https://www.redhat.com/archives/freeipa-users/2017-March/msg00339.html
6. Red Hat Directory Server - Chapter 14. Managing Replication 2017-09-20

   tags: 389-ds, linux, linux/centos, linux/red-hat, network/ldap, network/transport-layer-security, replication, security/authentication

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   • http://directory.fedoraproject.org/docs/389ds/howto/howto-replicationmonitoring.html
   • http://directory.fedoraproject.org/docs/389ds/howto/howto-walkthroughmultimasterssl.html
   • http://www.port389.org/docs/389ds/FAQ/faq.html#how-does-the-389-multi-master-replication-work
7. How To Set Up Centralized Linux Authentication with FreeIPA on CentOS 7 | DigitalOcean 2017-09-20

   tags: 389-ds, cryptography/certificate, linux, linux/centos, linux/red-hat, network/dns, network/ldap, security/authentication, single-sign-on

   [ permalink ]

   • https://www.freeipa.org/page/HowTos
8. LDAP - OpenLDAP or 389 DS? : linuxadmin 2017-09-20

   tags: 389-ds, kerberos, linux, linux/centos, network/ldap, security/authentication, single-sign-on

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9. CentOS 7.0 - man page for update-ca-trust (centos section 8) - Unix & Linux Commands 2017-06-30

   tags: cryptography/certificate, linux, linux/centos, linux/red-hat, network/transport-layer-security

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10. Postfix / Dovecot / ClamAV / Spamassassin 2016-12-12

    tags: antivirus, bayesian, email, email/dovecot, email/milter, email/sieve, email/spam, filter, linux, linux/centos, linux/debian, linux/red-hat, roundcube, sysadmin

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    A whole buncha' links with contradictory information on how to properly set up a mail server ;-)

    Disclaimer - My primary goal is to add proper Spamassassin (SA) filtering to an existing Postfix / Dovecot / roundcube installation, i.e.:

    • use SA as a milter (mail filter) to attribute a spam score to incoming mail
    • keep SA up-to-date
    • train SA with spam/ham from the users' virtual mailboxes
    • train SA according to user decisions (actual user or trained mail client with automatic/trained spam detection)

    Here we go!

    Most useful links; I stumbled upon them as soon as I knew what to look for:

    • https://workaround.org/ispmail/jessie/spamassassin
    • https://lelutin.ca/posts/installing_postfix_-_clamav_-_spamassassin_-_dovecot_-_postfixadmin_on_debian_squeeze/

    Official:

    • https://spamassassin.apache.org
    • https://spamassassin.apache.org/gtube/
    • https://wiki.apache.org/spamassassin/FrequentlyAskedQuestions

    Debian:

    • https://wiki.debian.org/DebianSpamAssassin
    • http://www.stefan-seelmann.de/wiki/mailserver-postfix-dovecot (wheezy)
    • https://www.christianroessler.net/tech/2015/spamassassin-dovecot-postfix.html
    • https://www.digitalocean.com/community/tutorials/how-to-configure-a-mail-server-using-postfix-dovecot-mysql-and-spamassassin

    CentOS:

    • https://www.rosehosting.com/blog/how-to-install-and-integrate-spamassassin-with-postfix-on-a-centos-6-vps/
    • https://www.rosehosting.com/blog/how-to-set-up-server-side-email-filtering-with-dovecot-sieve-and-roundcube-on-a-centos-6-vps/
    • http://shisaa.jp/postset/mailserver-1.html - a bit outdated but plenty of useful information regarding how components interact with each other
    • http://wiki2.dovecot.org/HowTo

    RHEL:

    • https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/ch-Mail_Servers.html
    • https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/s1-email-mta.html
    • https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/s1-email-mda.html
11. Install MATE or XFCE on CentOS 7 | Jensd's I/O buffer 2016-12-05

    tags: desktop, linux, linux/centos, xfce

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12. FreeIPA 2016-12-02

    tags: kerberos, linux, network/ldap, security/authentication, single-sign-on, sysadmin

    [ permalink ]

    LDAP/Kerberos directory server built on top of 389DS

    • http://www.freeipa.org/page/Deployment_Recommendations
    • http://www.freeipa.org/page/Quick_Start_Guide
    • http://arstechnica.com/civis/viewtopic.php?t=1163042
    • https://www.unixmen.com/configure-freeipa-server-centos-7/
13. 389 Directory Server 2016-12-01

    tags: 389-ds, directory, linux, linux/centos, linux/fedora, linux/red-hat, network/ldap, security/authentication

    [ permalink ]

    • https://www.linux.com/learn/simplify-ldap-fedoras-389-directory-server
    • https://www.rockstable.org/389-ds
    • https://github.com/jtgasper3/docker-images/tree/master/389-ds

    Administration WebApps:

    • http://directory.fedoraproject.org/docs/389ds/administration/webapps-install.html
    • http://directory.fedoraproject.org/docs/389ds/administration/dsgw.html
    • http://directory.fedoraproject.org/docs/389ds/administration/orgchart.html

    Install guides:

    • http://www.unixmen.com/install-and-configure-ldap-server-in-centos-7/
    • http://www.unixmen.com/manage-389-directory-server-graphically-using-389-management-console/
    • http://jensd.be/125/linux/rhel/install-mate-or-xfce-on-centos-7
    • http://unix.stackexchange.com/questions/181503/how-to-install-desktop-environments-on-centos-7