CentOS 8 End of Life has been effective since January 31 2021, official mirrors do not provide any packages anymore. Here is how to upgrade to latest release of CentOS 8 and switch to Stream. As always, prior to any system change, you should ensure you have a working recent backup. Upgrade to latest CentOS 8 sed -i -e 's/mirrorlist/#mirrorlist/g' -e 's|#baseurl=http://mirror.centos.org|baseurl=https://vault.centos.org|g' /etc/yum.repos.d/*.repo yum update reboot cat /etc/centos-release CentOS Linux release 8.5.2111 Make sure everything is working as expected. ...

Goals: collect observables from supported feeds collect observables from unsupported feeds with elastic-tip Setup elasticsearch and kibana for filebeat We could use superuser elastic to setup filebeat but we are going to use a dedicated user with just the minimum permissions. Open Kibana and go to Stack Management > Security > Roles. Click Create role and enter the following settings: Role name: filebeat_threatintel_setup Cluster privileges: monitor, manage_ilm, manage_ml Index privileges: Indices: filebeat-* Privileges: manage, write, read Click Create role. ...

Goals: single node elasticsearch single node kibana password for all accounts https between all components behind traefik future post: collect network logs (routers) future post: collect application logs (web servers, dns servers, docker) future post: collect application metrics future post: correlate with threat intelligence Create compose file version: '3' services: es: image: docker.elastic.co/elasticsearch/elasticsearch:7.16.3 container_name: elastic_es restart: always env_file: - ./.env environment: ES_JAVA_OPTS: "-Xms2g -Xmx2g" node.name: "es" discovery.type: "single-node" bootstrap.memory_lock: "true" # minimal security xpack.security.enabled: "true" # no encryption on internode communication xpack.security.transport.ssl.enabled: "false" # https traffic xpack.security.http.ssl.enabled: "true" xpack.security.http.ssl.key: "${CERTS_DIR}/es.key" xpack.security.http.ssl.certificate: "${CERTS_DIR}/es_chain.crt" xpack.security.http.ssl.certificate_authorities: "${CERTS_DIR}/ca.crt" ulimits: memlock: soft: -1 hard: -1 networks: - reverseproxy - default volumes: - data:/usr/share/elasticsearch/data - certs:${CERTS_DIR}:ro labels: - "traefik.enable=true" - "traefik.http.routers.elastic.rule=Host(`elasticsearch.foobar.com`)" - "traefik.http.routers.elastic.service=elastic" - "traefik.http.routers.elastic.tls=true" - "traefik.http.routers.elastic.tls.certresolver=le" - "traefik.http.routers.elastic.entrypoints=websecure" - "traefik.http.services.elastic.loadbalancer.server.port=9200" - "traefik.http.services.elastic.loadbalancer.server.scheme=https" - "traefik.http.services.elastic.loadbalancer.serversTransport=elastic" - "traefik.http.serversTransports.elastic.serverName=es" - "traefik.http.serversTransports.elastic.insecureSkipVerify=true" deploy: resources: limits: cpus: "4.0" memory: 4000M memswap_limit: 4000M kibana: image: docker.elastic.co/kibana/kibana:7.16.3 container_name: elastic_kibana restart: always depends_on: - es env_file: - ./.env - ./.env.kibana environment: - ELASTICSEARCH_URL="https://es:9200" - ELASTICSEARCH_HOSTS=["https://es:9200"] # minimal security: defined in environment files # kibana has to trust elasticsearch certificate - ELASTICSEARCH_SSL_CERTIFICATEAUTHORITIES="${CERTS_DIR}/ca.crt" # https traffic between other components and kibana - SERVER_SSL_ENABLED=true - SERVER_SSL_KEY=${CERTS_DIR}/kibana.key - SERVER_SSL_CERTIFICATE=${CERTS_DIR}/kibana_chain.crt - SERVER_PUBLICBASEURL=https://kibana.foobar.com networks: - reverseproxy - default volumes: - certs:${CERTS_DIR}:ro labels: - "traefik.enable=true" - "traefik.http.routers.kibana.rule=Host(`kibana.foobar.com`)" - "traefik.http.routers.kibana.service=kibana" - "traefik.http.routers.kibana.tls=true" - "traefik.http.routers.kibana.tls.certresolver=le" - "traefik.http.routers.kibana.entrypoints=websecure" - "traefik.http.services.kibana.loadbalancer.server.port=5601" - "traefik.http.services.kibana.loadbalancer.server.scheme=https" - "traefik.http.services.kibana.loadbalancer.serversTransport=kibana" - "traefik.http.serversTransports.kibana.serverName=kibana" - "traefik.http.serversTransports.kibana.insecureSkipVerify=true" deploy: resources: limits: cpus: "4.0" memory: 4000M memswap_limit: 4000M volumes: data: certs: name: elastic_certs external: true networks: reverseproxy: external: true Create a file named .env with the following content: ...

Traefik itself does not include WAF capabilities. If you want to add this capability, you can opt to replace Traefik with Apache httpd or nginx coupled with ModSecurity, however you loose the autoconfiguration of Traefik. Fortunately, Alexis Couvreur has developed a ModSecurity plugin for Traefik to forward requests received by Traefik to another webserver (running ModSecurity) before actually forwarding the requests to the application server. If the ModSecurity webserver returns a code > 400, then Traefik will reject the request, otherwise it will forward it to the application server. ...

Gitea is great when you want a fast, light and yet user-friendly git repositories. Alternatives would be Gogs, Gitlab or even Github. Gitea documentation tells you to use docker exec to perform a backup. However, this prevents you from using an additional volume to dump the backup into. Instead, I prefer to use a similar command using docker run. Assuming the following: the container network is called gitea_default, you only need this if you use an external database such as MySQL the container is called gitea the backup directory is in the current directory and named backups docker run --rm -it --network gitea_default --volumes-from gitea --volume $(pwd)/backups:/backups --user git --workdir /backups --entrypoint '/app/gitea/gitea' gitea/gitea:1.15.10 dump -c /data/gitea/conf/app.ini

If like me, you are trying to enable Audit Policies on Windows computers in a domain using Local Policies > Audit Policy, and it does not work, then you came to the right place. Legacy Audit Policy: audit object access settings in Local Security Policy The reason is: that is the legacy way to configure Audit Policies. Like Windows XP legacy. You will find plenty of resources out there telling you this is because Advanced Audit Policy is enabled and you need to disable it by setting Local Policies > Security Options > Audit: Force audit policy subcategory settings to override audit policy category settings to Disabled to make it work. While it is true that disabling the Advanced Audit Policy will make it work, it will revert to the old, non-granular way of configuring Audit Policies. ...

If you have the power of multiple servers connected to a UPS, you probably need to shut them down when the power goes down and before the UPS runs out of juice. Unless your UPS can be connected to the network, you usually can only connect a single device to it using good old serial or brand new USB. That single host now knows about the UPS status, but what about all the other systems? That’s when Network UPS Tools, aka NUT, comes into play. ...

Recently, I had to set up a new PKI. I was going to go with the good old OpenSSL but it’s 2021, there must be a more userfriendly and, more importantly, automated approach. There are many open-source possibilities: EJBCA, cfssl, Hashicorp Vault, Smallstep Certificates. I chose to use Smallstep certificates because it has all the features I need and they are not behind a pay-wall: lightweight: small Go binary, you can run it with a file-based database (similar to SQLite) user friendly CLI: compared to openssl commands ACME protocol: useful for Traefik reverse proxy OIDC authentication support: the guys are super friendly and available on their Discord channel Be sure to check their website, they have other features that you might want, especially their Certificate Manager. They also have a SaaS offering if you do not want to get your hands dirty. ...

If you plan to buy the Antec NX800 for your new build, you should be aware of a couple of things. First, it is one of the cheap-ish cases that support a 280mm radiator at the top. This is the primary reason I bought this case. Second, if you mount a radiator at the top, mount it last. Especially, mount it after you screwed the motherboard and plugged all cables (especially CPU power and fans). Accessing them with the radiator mounted will be difficult or even impossible. ...

When I moved in Luxembourg, I subscribed to Tango Luxembourg Fiber internet access. Back then, I got the usual dynamic public IP address “for free”. It was changing every 36 hours but at least it was a public one. Recently, I changed my subscription to the 1 gigabit/s offer and soon after, I realized my VPNs and 6to4 tunnel was not working anymore. After a brief troubleshooting session, I found out I was receiving a private IP address instead of the usual public 94.252.x.x . ...