Pass through environment to scheduler, web and launcher

These components may need to have http_proxy set, so let the user
pass env variables.

Change-Id: I6191dd9c8ded70c715f13179c3d904e8f65e144d

doc/source/index.rst

@@ -355,6 +355,13 @@ verbatim):
             * ``tls.crt``
             * ``tls.key``
 
+      .. attr:: env
+
+         A list of environment variables.  This will be passed through
+         to the Pod specifications for the scheduler, launcher, and
+         web.  This may be used to set http_proxy environment
+         variables.
+
       .. attr:: scheduler
 
          .. attr:: config

zuul_operator/templates/nodepool-launcher.yaml

@@ -28,9 +28,7 @@ spec:
       containers:
       - name: launcher
         image: {{ spec.imagePrefix }}/nodepool-launcher:{{ spec.nodepoolImageVersion }}
-        env:
-        - name: KUBECONFIG
-          value: /etc/kubernetes/kube.config
+        env: {{ spec.env | zuul_to_json }}
         volumeMounts:
         - name: nodepool-config
           mountPath: /etc/nodepool

zuul_operator/templates/zuul.yaml

@@ -166,6 +166,7 @@ spec:
           readOnly: true
         {%- endif %}
         {%- endfor %}
+        env: {{ spec.env | zuul_to_json }}
       volumes:
       - name: zuul-config
         secret:
@@ -232,6 +233,7 @@ spec:
         - name: zookeeper-client-tls
           mountPath: /tls/client
           readOnly: true
+        env: {{ spec.env | zuul_to_json }}
       volumes:
       - name: zuul-config
         secret:
@@ -365,7 +367,7 @@ spec:
       - name: nodepool-private-key
         secret:
           secretName: {{ executor_ssh_secret }}
-      {%- endif %}          
+      {%- endif %}
       {%- for volume in spec.get('jobVolumes', []) %}
       - {{ volume.volume | zuul_to_json }}
       {%- endfor %}

zuul_operator/zuul.py

@@ -86,6 +86,20 @@ class Zuul:
         self.spec.setdefault('zuulRegistryImageVersion', 'latest')
         self.spec.setdefault('nodepoolImageVersion', 'latest')
 
+        default_env = {
+            'KUBECONFIG': '/etc/kubernetes/kube.config'
+        }
+        env = self.spec.setdefault('env', [])
+        for default_key, default_value in default_env.items():
+            # Don't allow the user to override our defaults
+            for item in env:
+                if item.get('name') == default_key:
+                    env.remove(item)
+                    break
+            # Set our defaults
+            env.append({'name': default_key,
+                        'value': default_value})
+
         self.cert_manager = certmanager.CertManager(
             self.api, self.namespace, self.log)
         self.installing_cert_manager = False