Deepak Prasad

Remove extra Python 3.11–3.15 on Ubuntu 22.04, 24.04, or 26.04 safely—uninstall Deadsnakes packages, delete source altinstall files, clean pyenv and uv, and keep Ubuntu system python3 working.

Create a private root CA on Linux with OpenSSL 3.x—passphrase-protected or unencrypted root key, self-signed certificate with CA extensions, verification, and safe key handling before you build an intermediate chain.

Get passwordless Keycloak Windows SSO with Active Directory Kerberos SPNEGO after the SPN and keytab are set—vm1.lab.example URL, Edge AuthServerAllowlist, principal LDAP lookup, curl Negotiate proof, and silent browser …

Connect Keycloak 26.7.3 to OpenLDAP with LDAP user federation—bind DN, Users DN, uid and entryUUID mapping, full user sync, and OpenLDAP password login through Keycloak.

Configure Keycloak 26.7.3 Kerberos against Microsoft AD—HTTP SPN, keytab, krb5 realm mapping, and Allow Kerberos authentication on the existing lab-ad LDAP provider without a second Kerberos federation provider.

How Keycloak identity brokering works: upstream IdPs, broker endpoints, first broker login, OIDC and SAML paths, and how brokering differs from LDAP and Kerberos user federation.

Troubleshoot Keycloak 26.7.3 when Active Directory users sync but cannot sign in—wrong password vs bind account, userAccountControl, pwdLastSet, disabled accounts, and LDAP error 52e on RHEL.

Provision Microsoft Entra ID users into Keycloak with native SCIM: User Profile externalId, OAuth client credentials, Entra non-gallery provisioning, attribute matching, and verification.

Fix Keycloak SAML Invalid Destination errors by comparing the SAMLResponse Destination with the broker ACS URL, then correcting the IdP ACS, hostname, or reverse-proxy configuration.

Connect Keycloak 26.7.3 to Microsoft Active Directory over LDAPS on port 636—DC certificate trust, StartTLS vs LDAPS for AD, provider settings, ldapsearch checks, and Test connection.

Configure Keycloak SCIM authentication with confidential service-account clients, the SCIM audience claim, and least-privilege realm-management roles for read vs provision access.

Configure a service provider as a Keycloak SAML client—Client ID, ACS URL, redirect URI, NameID format, and signing options—then test one SP-initiated login on Keycloak 26.7.3.

Use a Keycloak realm as a SAML 2.0 identity provider—stable hostname, IdP metadata URL, signing keys, and what to give the service provider before you register a SAML client.

Troubleshoot Keycloak 26.7.3 when Active Directory user sync imports zero users—Users DN and search scope under CN=Users, custom LDAP filters, bind error 49 data 52e, and ldapsearch checks on RHEL.

Troubleshoot Keycloak 26.7.3 when Active Directory group sync imports zero groups or users miss LDAP memberships—LDAP Groups DN, Builtin vs OU, memberOf vs recursive retrieve strategy, and nested AD groups on RHEL.

Choose sAMAccountName or userPrincipalName as the Keycloak Active Directory username LDAP attribute—canonical username, realm login settings, provider change with automatic username mapper sync on Keycloak 26.x, and lab …

Map Microsoft Active Directory security groups to Keycloak realm roles with the LDAP group mapper, memberOf membership, nested group hierarchy, group sync, and access-token verification on Keycloak 26.7.3.

Integrate Keycloak 26.7.3 with Microsoft Active Directory—LDAP user federation, StartTLS, user sync, AD password login through Keycloak, and READ_ONLY vs WRITABLE edit modes.

Create a general-purpose Amazon S3 bucket with modern ownership and access defaults, upload a file, use a presigned URL for temporary access, and verify objects with the AWS CLI.

Create an Amazon ElastiCache for Redis cluster in the AWS console, place it in a VPC subnet group, restrict port 6379 with a security group, and verify PING and SET from a Linux EC2 instance.

Create a gp3 EBS volume, attach and mount it on a Linux EC2 instance in the same Availability Zone, write data, keep the volume after termination, snapshot it, and restore the file from a new volume.

Free, hands-on Wireshark course covering packet capture, display filters, TCP analysis, TLS and IPsec decryption, and network troubleshooting.

Create an Amazon DynamoDB table with a partition key, add items in the console, read data with scan and get-item in the AWS CLI, and compare on-demand with provisioned capacity.

Create a Cognito user pool with Managed login and a public OAuth app client, sign in through the login page, link an identity pool, and verify STS temporary credentials from a user pool ID token.

Publish plain HTML, CSS, JavaScript, and images on AWS Amplify Hosting with HTTPS on an amplifyapp.com URL, using zip upload or GitHub, then connect a custom domain with managed TLS.

Host plain HTML, CSS, JavaScript, and images on Cloudflare Pages with free HTTPS and a pages.dev URL, then optionally attach your own domain when the zone uses Cloudflare DNS.

Publish plain HTML, CSS, JavaScript, and images on GitHub Pages with a free github.io URL and HTTPS, using the GitHub web interface—no web server to manage.

Plan monthly AWS costs first, then host a static site on Amazon S3 behind CloudFront with a public ACM certificate, Route 53 DNS, and HTTPS on your own domain—without exposing the bucket to the public internet.

Decrypt HTTPS and LDAPS in Wireshark with SSLKEYLOGFILE, see which TLS libraries actually write the key log, and fix an empty or mismatched session-secret file.

Learn how to check whether SSH is using protocol 1 or 2, what OpenSSH version strings such as OpenSSH_7.4p1 mean, and how to read SSH-2.0 banners and verbose SSH output.