Template Syntax

Conjure uses Go's template engine, which provides powerful text transformation capabilities. This guide covers all the syntax you need to create dynamic templates.

Replace placeholders with variable values:

name: {{.app_name}}
namespace: {{.namespace}}
port: {{.port}}

Input variables:

app_name: my-api
namespace: production
port: 8080

The . (dot) refers to the current context, which is your variables object:

{{.variable_name}}

{{if .enable_monitoring}}
monitoring:
  enabled: true
{{end}}

When enable_monitoring: true:

monitoring:
  enabled: true

When enable_monitoring: false:

# Nothing rendered

{{if .enable_tls}}
protocol: https
port: 443
{{else}}
protocol: http
port: 80
{{end}}

{{if eq .environment "production"}}
replicas: 10
{{else if eq .environment "staging"}}
replicas: 5
{{else}}
replicas: 1
{{end}}

{{if not .enable_debug}}
logLevel: info
{{else}}
logLevel: debug
{{end}}

{{if eq .service_type "LoadBalancer"}}
externalTrafficPolicy: Local
{{end}}

Multiple values:

{{if eq .environment "production" "prod" "prd"}}
# Matches if environment is any of these values
{{end}}

{{if ne .environment "development"}}
# Renders if environment is NOT development
{{end}}

Operator	Meaning	Example
eq	Equal	{{if eq .env "prod"}}
ne	Not equal	{{if ne .env "dev"}}

Important

Numeric Comparisons Not Supported: While Go templates support numeric comparison operators (lt, le, gt, ge), Conjure stores all variables as strings regardless of the type field in metadata. This means numeric comparisons will not work as expected. Use string comparisons with eq and ne instead.

For example, instead of {{if ge .replicas 5}}, use categorical variables like scale_tier with values small, medium, large and compare with {{if eq .scale_tier "large"}}.

{{if and .enable_tls .enable_auth}}
# Renders if both are true
secureMode: true
{{end}}

{{if or .is_production .is_staging}}
# Renders if either is true
highAvailability: true
{{end}}

{{if and (eq .environment "production") (eq .scale_tier "large")}}
# Production AND large scale
autoscaling: true
{{end}}

Templates preserve whitespace:

{{if .feature}}
enabled: true
{{end}}

Output with feature: true:

enabled: true

Notice the blank lines.

Use - to trim whitespace:

{{- if .feature}}
enabled: true
{{- end}}

Output:

enabled: true

Left trim:

{{- .value}}

Right trim:

{{.value -}}

Both:

{{- .value -}}

apiVersion: v1
kind: Service
metadata:
  name: {{.app_name}}
{{- if .enable_monitoring}}
  annotations:
    prometheus.io/scrape: "true"
{{- end}}
spec:
  selector:
    app: {{.app_name}}

Without -, you'd get blank lines in the output.

Comments that don't appear in output:

{{/* This is a comment */}}
apiVersion: v1
kind: Service

Multi-line comments:

{{/*
This is a multi-line comment
It won't appear in the output
*/}}

Regular YAML comments appear in output:

# This is a YAML comment - appears in output
apiVersion: v1

message: {{print "Hello " .name "!"}}

Output with name: World:

message: Hello World!

version: {{printf "v%s" .version}}

Output with version: 1.2.3:

version: v1.2.3

{{if .enable_database}}
database:
  {{if eq .database_type "postgres"}}
  type: postgresql
  port: 5432
  {{else if eq .database_type "mysql"}}
  type: mysql
  port: 3306
  {{else}}
  type: sqlite
  {{end}}
{{end}}

{{if and (eq .environment "production") (eq .region "us-east-1")}}
# Specific production region config
{{else if eq .environment "production"}}
# General production config
{{else}}
# Other environments
{{end}}

metadata:
  labels:
    app: {{.app_name}}
    environment: {{.environment}}
    {{- if .team}}
    team: {{.team}}
    {{- end}}
    {{- if .cost_center}}
    cost-center: {{.cost_center}}
    {{- end}}

{{if eq .environment "production"}}
replicas: 10
resources:
  requests:
    cpu: 1000m
    memory: 2Gi
  limits:
    cpu: 2000m
    memory: 4Gi
{{else if eq .environment "staging"}}
replicas: 3
resources:
  requests:
    cpu: 500m
    memory: 1Gi
  limits:
    cpu: 1000m
    memory: 2Gi
{{else}}
replicas: 1
resources:
  requests:
    cpu: 250m
    memory: 512Mi
  limits:
    cpu: 500m
    memory: 1Gi
{{end}}

spec:
  containers:
  - name: {{.app_name}}
    image: {{.image}}
    {{- if .enable_health_checks}}
    livenessProbe:
      httpGet:
        path: /health
        port: {{.port}}
      initialDelaySeconds: 30
      periodSeconds: 10
    readinessProbe:
      httpGet:
        path: /ready
        port: {{.port}}
      initialDelaySeconds: 5
      periodSeconds: 5
    {{- end}}
    {{- if .enable_metrics}}
    env:
    - name: METRICS_ENABLED
      value: "true"
    - name: METRICS_PORT
      value: "{{.metrics_port}}"
    {{- end}}

spec:
  type: {{.service_type}}
  {{- if eq .service_type "LoadBalancer"}}
  loadBalancerSourceRanges:
  - {{.allowed_cidr}}
  externalTrafficPolicy: Local
  {{- else if eq .service_type "NodePort"}}
  sessionAffinity: ClientIP
  {{- end}}

Add temporary debug output:

{{/* DEBUG: app_name = {{.app_name}} */}}
{{/* DEBUG: replicas = {{.replicas}} */}}

Generate and check the comments in output.

If your template has syntax errors, you'll see:

Error: failed to parse template

Common issues:

• Unclosed {{if}} (missing {{end}})
• Typo in function name
• Missing closing braces }}

# Good - clean output
{{- if .feature}}
enabled: true
{{- end}}

# Bad - extra blank lines
{{if .feature}}
enabled: true
{{end}}

# Good - clear structure
{{- if .enable_monitoring}}
annotations:
  prometheus.io/scrape: "true"
  prometheus.io/port: "9090"
{{- end}}

# Bad - scattered
{{- if .enable_monitoring}}
annotations:
  prometheus.io/scrape: "true"
{{- end}}
{{- if .enable_monitoring}}
  prometheus.io/port: "9090"
{{- end}}

replicas: {{if .replicas}}{{.replicas}}{{else}}3{{end}}

Or better, set defaults in metadata and use:

replicas: {{.replicas}}