Use httptester docker image for http tests (#15811)

* Use httptester docker image for http tests

* When not running with an httptester linked container, use public test sites

test/integration/roles/prepare_http_tests/defaults/main.yml

@@ -0,0 +1,3 @@
+badssl_host: wrong.host.badssl.com
+httpbin_host: httpbin.org
+sni_host: sni.velox.ch

test/integration/roles/prepare_http_tests/tasks/main.yml

@@ -0,0 +1,35 @@
+# The docker --link functionality gives us an ENV var we can key off of to see if we have access to
+# the httptester container
+- set_fact:
+    has_httptester: "{{ lookup('env', 'ANSIBLE.HTTP.TESTS_PORT_80_TCP_ADDR') != '' }}"
+
+# If we are running with access to a httptester container, grab it's cacert and install it
+- block:
+    # Override hostname defaults with httptester linked names
+    - include_vars: httptester.yml
+
+    - name: RedHat - Enable the dynamic CA configuration feature
+      command: update-ca-trust force-enable
+      when: ansible_os_family == 'RedHat'
+
+    - name: RedHat - Retrieve test cacert
+      get_url:
+        url: "http://ansible.http.tests/cacert.pem"
+        dest: "/etc/pki/ca-trust/source/anchors/ansible.pem"
+      when: ansible_os_family == 'RedHat'
+
+    - name: Debian - Retrieve test cacert
+      get_url:
+        url: "http://ansible.http.tests/cacert.pem"
+        dest: "/usr/local/share/ca-certificates/ansible.crt"
+      when: ansible_os_family == 'Debian'
+
+    - name: Redhat - Update ca trust
+      command: update-ca-trust extract
+      when: ansible_os_family == 'RedHat'
+
+    - name: Debian - Update ca certificates
+      command: update-ca-certificates
+      when: ansible_os_family == 'Debian'
+
+  when: has_httptester|bool

test/integration/roles/prepare_http_tests/vars/httptester.yml

@@ -0,0 +1,4 @@
+# these are fake hostnames provided by docker link for the httptester container
+badssl_host: fail.ansible.http.tests
+httpbin_host: ansible.http.tests
+sni_host: sni1.ansible.http.tests