added k8s manifests

Dockerfile

@@ -0,0 +1,34 @@
+# Use RHEL 9 UBI as the base
+FROM registry.access.redhat.com/ubi9/ubi-minimal:latest
+
+# Define Mattermost version and architecture
+ARG MM_VERSION=11.4.0
+ARG MM_PACKAGE=mattermost-${MM_VERSION}-linux-amd64.tar.gz
+
+# Set environment variables
+ENV PATH="/mattermost/bin:${PATH}"
+ENV MM_INSTALL_TYPE=docker
+
+# 1. Install necessary dependencies
+# 2. Create mattermost user/group for security
+# 3. Download and extract the binary
+RUN microdnf update -y && \
+    microdnf install -y tar gzip shadow-utils ca-certificates findutils && \
+    groupadd -g 2000 mattermost && \
+    useradd -u 2000 -g mattermost -m -s /sbin/nologin mattermost && \
+    curl -L https://releases.mattermost.com/${MM_VERSION}/${MM_PACKAGE} | tar -xz && \
+    mkdir -p /mattermost/data /mattermost/plugins /mattermost/client/plugins && \
+    chown -R mattermost:mattermost /mattermost && \
+    microdnf clean all
+
+# Set the working directory
+WORKDIR /mattermost
+
+# Mattermost uses these ports
+EXPOSE 8065 8067
+
+# Switch to non-root user
+USER mattermost
+
+# Start the Mattermost server
+CMD ["mattermost"]