First Kubernetes implementation

README.md

@@ -47,7 +47,7 @@ The environment variables will setup the HAProxy.
 
 | Environment Variable          | Description                                                                                                   |
 |-------------------------------|---------------------------------------------------------------------------------------------------------------|
-| EASYHAPROXY_DISCOVER          | How `haproxy.cfg` will be created: `static`, `docker` or `swarm`                                              |
+| EASYHAPROXY_DISCOVER          | How `haproxy.cfg` will be created: `static`, `docker`, `swarm` or `kubernetes`                                  |
 | EASYHAPROXY_LABEL_PREFIX      | (Optional) The key will search for matching resources. Default: `easyhaproxy`.                                |
 | EASYHAPROXY_LETSENCRYPT_EMAIL | (Optional) The email will be used to request the certificate to Letsencrypt                                   |      
 | EASYHAPROXY_SSL_MODE          | (Optional) `STRICT` supports only the most recent TLS version; `DEFAULT` good SSL integration with recent browsers; `LOOSE` supports all old SSL protocols for old browsers (not recommended).  |    
@@ -100,7 +100,48 @@ The discovery will occur every minute.
 
 Important: easyhaproxy needs to be in the same network of the containers or otherwise will not access.
 
-### Docker Container (Swarm or Docker) tags:
+### EASYHAPROXY_DISCOVER: kubernetes (experimental and limited)
+
+This will query all `ingress` in the kubernetes cluster and check the annotation `kubernetes.io/ingress.class: easyhaproxy-ingress`. 
+
+e.g.:
+```
+kind: Ingress
+metadata:
+  annotations:
+    kubernetes.io/ingress.class: easyhaproxy-ingress
+  name: example-ingress
+  namespace: example
+spec:
+  rules:
+  - host: example.org
+    http:
+      paths:
+      - backend:
+          service:
+            name: example-service
+            port:
+              number: 8080
+        pathType: ImplementationSpecific
+  - host: www.example.org
+    http:
+      paths:
+      - backend:
+          service:
+            name: example-service
+            port:
+              number: 8080
+        pathType: ImplementationSpecific
+```
+
+At this point the implementation is very limited and doesn't support all ingress properties nor wildcard domains. 
+
+The system will read only `host` and `port.number`
+
+There is no necessary to add labels or annotations.
+
+
+### Container (Docker or Swarm) labels:
 
 | Tag                                   | Description                                                                                             | Example      |
 |---------------------------------------|---------------------------------------------------------------------------------------------------------|--------------|

assets/scripts/haproxy-reload.sh

@@ -6,11 +6,6 @@ cd /scripts
 
 RELOAD="true"
 
-if [[ "static|docker|swarm" != *"$EASYHAPROXY_DISCOVER"* ]];then
-    log "error" "CONF_CHECK" "EASYHAPROXY_DISCOVER should be 'static', 'docker', or 'swarm'. I got '$EASYHAPROXY_DISCOVER' instead."
-    exit 1
-fi
-
 if [[ "$EASYHAPROXY_DISCOVER" == "static" ]]; then
     CONTROL_FILE="/etc/haproxy/haproxy.cfg"
     touch ${CONTROL_FILE}
@@ -22,21 +17,34 @@ else
     mv ${CONTROL_FILE} ${CONTROL_FILE}.old
     touch ${CONTROL_FILE}
 
-    if [[ "$EASYHAPROXY_DISCOVER" == "docker" ]]; then
+    case "$EASYHAPROXY_DISCOVER" in
+        docker)
             CONTAINERS=$(docker ps -q | sort | uniq)
             LABEL_PATH=".Config.Labels"
 
             for container in ${CONTAINERS}; do
                 docker inspect --format "{{ json $LABEL_PATH }}" ${container} | xargs -I % echo ${container}=% >> ${CONTROL_FILE}
             done
-    else
+            ;;
+
+        swarm)
             CONTAINERS=$(docker node ps $(docker node ls -q) --format "{{ .Name }}" --filter desired-state=running | cut -d. -f1 | sort | uniq)
             LABEL_PATH=".Spec.Labels"
 
             for container in ${CONTAINERS}; do
                 docker service inspect --format "{{ json $LABEL_PATH }}" ${container} | xargs -I % echo ${container}=% >> ${CONTROL_FILE}
             done
-    fi
+            ;;
+
+        kubernetes)
+            python3 /scripts/k8s.py > ${CONTROL_FILE}
+            ;;
+
+        *)
+            log "error" "CONF_CHECK" "EASYHAPROXY_DISCOVER should be 'static', 'docker', 'swarm' or kubernetes. I got '$EASYHAPROXY_DISCOVER' instead."
+            exit 1
+            ;;
+    esac
 
     if cmp -s ${CONTROL_FILE} ${CONTROL_FILE}.old ; then
         RELOAD="false"

assets/scripts/k8s.py

@@ -0,0 +1,50 @@
+from kubernetes import client, config
+from kubernetes.client.rest import ApiException
+import json
+
+# https://github.com/kubernetes-client/python/tree/master/kubernetes/docs
+
+def main():
+    config.load_incluster_config()
+
+    api_instance = client.CoreV1Api()
+    v1 = client.NetworkingV1Api()
+    
+    ret = v1.list_ingress_for_all_namespaces(watch=False)
+
+    discover = {}
+    for i in ret.items:
+        if i.metadata.annotations['kubernetes.io/ingress.class'] != "easyhaproxy-ingress":
+            continue
+
+        data = {}
+        #ingress_name = i.metadata.name
+        data["creation_timestamp"] = i.metadata.creation_timestamp.strftime("%x %X")
+        data["resource_version"] = i.metadata.resource_version
+        data["namespace"] = i.metadata.namespace
+        for rule in i.spec.rules:
+            rule_data = {}
+            port_number = rule.http.paths[0].backend.service.port.number
+            definition = rule.host.replace(".", "-")
+            rule_data["easyhaproxy.%s_%s.host" % (definition, port_number)] = rule.host
+            rule_data["easyhaproxy.%s_%s.port" % (definition, port_number)] = "80"
+            rule_data["easyhaproxy.%s_%s.localport" % (definition, port_number)] = port_number
+            service_name = rule.http.paths[0].backend.service.name
+            try:
+                api_response = api_instance.read_namespaced_service(service_name, i.metadata.namespace)
+                cluster_ip = api_response.spec.cluster_ip
+            except ApiException as e:
+                cluster_ip = None
+                # print("Exception when calling CoreV1Api->read_namespaced_service: %s\n" % e)
+            
+            if cluster_ip is not None:
+                if cluster_ip not in discover.keys():
+                    discover[cluster_ip] = data
+                discover[cluster_ip].update(rule_data)
+
+    for k in discover.keys():
+        print("%s=%s" % (k, json.dumps(discover[k])))
+
+if __name__ == '__main__':
+    main()
+

kubernetes/easyhaproxy.yml

@@ -0,0 +1,61 @@
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: easyhaproxy
+
+---
+apiVersion: apps/v1
+kind: DaemonSet
+metadata:
+  name: easyhaproxy-ingress
+  namespace: easyhaproxy
+spec:
+  selector:
+    matchLabels:
+      app: easyhaproxy-ingress
+  template:
+    metadata:
+      labels:
+        app: easyhaproxy-ingress
+    spec:
+      serviceAccountName: easyhaproxy-ingress
+      containers:
+      - image: byjg/easy-haproxy:kubernetes
+        imagePullPolicy: IfNotPresent
+        name: easyhaproxy-ingress
+        ports:
+        - name: http
+          containerPort: 80
+          hostPort: 80
+        - name: https
+          containerPort: 443
+          hostPort: 443
+        - name: stats
+          containerPort: 1943
+          hostPort: 1943
+        resources:
+          requests:
+            cpu: "100m"
+            memory: "128Mi"
+         #limits:
+         #  cpu: "1"
+         #  memory: "1Gi"
+        securityContext:
+          allowPrivilegeEscalation: true
+          #runAsUser: 101 #nginx
+          capabilities:
+            drop:
+            - ALL
+            add:
+            - NET_BIND_SERVICE
+        env:
+        - name: EASYHAPROXY_DISCOVER
+          value: kubernetes
+        - name: HAPROXY_USERNAME
+          value: admin
+        - name: HAPROXY_PASSWORD
+          value: password
+        - name: EASYHAPROXY_REFRESH_CONF
+          value: 10
+

requirements.txt

@@ -2,3 +2,4 @@ pyyaml
 docker
 jinja2
 pytest
+kubernetes