feat: add stable bootstrap node

k8s/charts/codex/templates/codex-statefulset.yaml

@@ -5,7 +5,10 @@ metadata:
   namespace: {{ .Release.Namespace }}
 
 spec:
-  replicas: {{ .Values.experiment.networkSize }}
+  # The last node in the statefulset will be used as a stable bootstrap node. Since it's not
+  # involved in the experiment, it's less likely to crash and cause network partitions which will
+  # freeze the whole experiment.
+  replicas: {{ add .Values.experiment.networkSize 1 }}
   serviceName: {{ include "codex-nodes.service" . }}
   podManagementPolicy: Parallel
   selector:
@@ -46,9 +49,9 @@ spec:
             - containerPort: 6890
           resources:
             requests:
-              memory: 6Gi
+              memory: {{ .Values.experiment.memory | quote }}
             limits:
-              memory: 6Gi
+              memory: {{ .Values.experiment.memory | quote }}
           env:
             - name: POD_IP
               valueFrom:
@@ -77,7 +80,7 @@ spec:
             - name: CODEX_LOG_LEVEL
               value: {{ .Values.experiment.codexLogLevel }}
             - name: BOOTSTRAP_NODE
-              value: "{{ include "codex-nodes.statefulset" . }}-{{ .Values.experiment.bootstrapNodeIndex }}"
+              value: "{{ include "codex-nodes.statefulset" . }}-{{ .Values.experiment.networkSize }}"
           command: [ "/bin/bash", "--login", "-c" ]
           args:
             - |

k8s/charts/codex/values.yaml

@@ -7,8 +7,8 @@ experiment:
 
   blockTTL: 360000
   blockMaintenanceInterval: 360000
-  bootstrapNodeIndex: 0
   codexLogLevel: debug
+  memory: "1Gi"
 
   # Experiments are ran as part of groups which may entail several invocations for this Helm chart.
   # We therefore identify both the experiment within a group, and the group itself.