chore: include doc+script for installing RHDH 1.6 (RHIDP-1477, RHIDP-6668, RHIDP-7251) - partial pick from main [release-1.6] (#158)

Signed-off-by: Nick Boldt <nboldt@redhat.com>

Author: nickboldt

.rhdh/docs/installing-ci-charts.adoc

@@ -0,0 +1,20 @@
+== Installing CI builds of RHDH through the chart
+
+=== Script install prerequisites
+* Openshift CLI
+* Helm CLI
+
+=== Scripted installation
+
+To link:../scripts/install.sh[install] from a Helm Chart Registry, run the following commands:
+
+```
+cd /tmp
+# Create or select a namespace
+# Install the chart repo
+# Install the chart, then update the clusterRouterBase
+curl -sSLO https://raw.githubusercontent.com/redhat-developer/rhdh-chart/refs/heads/main/.rhdh/scripts/install.sh && chmod +x install.sh
+./install.sh 1.7-20-CI --namespace rhdh-1-7-20-ci
+```
+
+That's it! 

.rhdh/scripts/install.sh

@@ -0,0 +1,104 @@
+#!/bin/bash
+# install a helm chart with the correct global.clusterRouterBase
+
+# default namespace if none set
+namespace="rhdh-helm"
+# chartrepo=0 # by default don't create a new chart repo unless the version chart version includes "CI" suffix
+
+usage ()
+{
+  echo "Usage: $0 CHART_VERSION [-n namespace]
+
+Requires an existing connection to an OCP or k8s cluster
+Requires helm, plus oc or kubectl, to be installed and on the path
+
+Examples:
+  $0 1.5.1 
+  $0 1.7-zzz-CI -n rhdh-ci
+
+Options:
+  -n, --namespace   Project or namespace into which to install specified chart; default: $namespace
+      --chartrepo   If set, a Helm Chart Repo will be applied to the cluster, based on the chart version.
+                    If CHART_VERSION ends in CI, this is done by default.
+      --router      If set, the cluster router base is manually set. 
+                    Required for non-admin users
+                    Redundant for admin users
+"
+}
+
+if [[ $# -lt 1 ]]; then usage; exit 0; fi
+
+while [[ "$#" -gt 0 ]]; do
+  case $1 in
+    '--chartrepo') chartrepo=1;;
+    '-n'|'--namespace') namespace="$2"; shift 1;;
+    '-h') usage; exit 0;;
+    '--router') CLUSTER_ROUTER_BASE="$2"; shift 1;;
+    *) CV="$1";;
+  esac
+  shift 1
+done
+
+if [[ ! "$CV" ]]; then usage; exit 1; fi
+
+CHART_URL="oci://quay.io/rhdh/chart"
+
+if ! helm show chart $CHART_URL --version "$CV" &> /dev/null; then 
+  echo "Error: could not load chart $CV from $CHART_URL !"
+  echo
+  usage
+  exit 1
+  fi
+
+echo "Using ${CHART_URL} to install Helm chart"
+
+# choose namespace for the install (or create if non-existant)
+oc new-project "$namespace" || oc project "$namespace"
+
+# generate repo.yaml and index.yaml so we don't have to publish a new file every time
+if [[ "$CV" == *"-CI" ]] || [[ $chartrepo -eq 1 ]]; then
+  mkdir -p /tmp/"$CV"-unpacked && pushd /tmp/"$CV"-unpacked >/dev/null 2>&1 || exit 1
+  helm pull oci://quay.io/rhdh/chart --version "$CV" -d /tmp/"$CV"-unpacked # get tarball
+  helm repo index /tmp/"$CV"-unpacked # create index.yaml
+  cat <<EOF > repo.yaml
+apiVersion: helm.openshift.io/v1beta1
+kind: HelmChartRepository
+metadata:
+  name: rhdh-next-ci-repo
+spec:
+  connectionConfig:
+    file: >-
+      ./index.yaml
+EOF
+
+  oc apply -f repo.yaml || kubctl apply -f repo.yaml
+  popd  >/dev/null 2>&1 || exit 1
+
+  # clean up temp files
+  rm -fr /tmp/"$CV"-unpacked
+fi
+
+# 1. install (or upgrade)
+helm upgrade redhat-developer-hub -i "${CHART_URL}" --version "$CV"
+
+# 2. collect values
+PASSWORD=$(kubectl get secret redhat-developer-hub-postgresql -o jsonpath="{.data.password}" | base64 -d)
+if [[ $(oc auth can-i get route/openshift-console) == "yes" ]]; then
+  CLUSTER_ROUTER_BASE=$(oc get route console -n openshift-console -o=jsonpath='{.spec.host}' | sed 's/^[^.]*\.//')
+elif [[ -z $CLUSTER_ROUTER_BASE ]]; then
+  echo "Error: openshift-console routes cannot be accessed with user permissions"
+  echo "Rerun command installation script with --router <cluster router base>"
+  echo
+  usage
+  exit 1
+fi
+
+# 3. change values
+helm upgrade redhat-developer-hub -i "${CHART_URL}" --version "$CV" \
+    --set global.clusterRouterBase="${CLUSTER_ROUTER_BASE}" \
+    --set global.postgresql.auth.password="$PASSWORD"
+
+echo "
+Once deployed, Developer Hub $CV will be available at
+https://redhat-developer-hub-${namespace}.${CLUSTER_ROUTER_BASE}
+"