Better DNS-over-HTTPS support. (#908)

This change:

Allows resolution hostnames in URLs using dnspython's resolver
or via a bootstrap address, without rewriting URLs.

Adds full support for source addresses and ports to
httpx, except for asyncio I/O where only the source address
can be specified.

Removes support for requests.

2 files changed, 6 insertions, 25 deletions

diff --git a/examples/doh-json.py b/examples/doh-json.py
index e9fa087..c8d830b 100755
--- a/examples/doh-json.py
+++ b/examples/doh-json.py
@@ -2,7 +2,7 @@
 
 import copy
 import json
-import requests
+import httpx
 
 import dns.flags
 import dns.message
@@ -92,7 +92,7 @@ def from_doh_simple(simple, add_qr=False):
 a = dns.resolver.resolve("www.dnspython.org", "a")
 p = to_doh_simple(a.response)
 print(json.dumps(p, indent=4))
-response = requests.get(
+response = httpx.get(
     "https://dns.google/resolve?",
     verify=True,
     params={"name": "www.dnspython.org", "type": 1},
diff --git a/examples/doh.py b/examples/doh.py
index 17787ed..2fd44ff 100755
--- a/examples/doh.py
+++ b/examples/doh.py
@@ -1,11 +1,7 @@
 #!/usr/bin/env python3
 #
 # This is an example of sending DNS queries over HTTPS (DoH) with dnspython.
-# Requires use of the requests module's Session object.
-#
-# See https://2.python-requests.org/en/latest/user/advanced/#session-objects
-# for more details about Session objects
-import requests
+import httpx
 
 import dns.message
 import dns.query
@@ -13,31 +9,16 @@ import dns.rdatatype
 
 
 def main():
-    where = "1.1.1.1"
+    where = "https://dns.google/dns-query"
     qname = "example.com."
-    # one method is to use context manager, session will automatically close
-    with requests.sessions.Session() as session:
+    with httpx.Client() as client:
         q = dns.message.make_query(qname, dns.rdatatype.A)
-        r = dns.query.https(q, where, session=session)
+        r = dns.query.https(q, where, session=client)
         for answer in r.answer:
             print(answer)
 
         # ... do more lookups
 
-    where = "https://dns.google/dns-query"
-    qname = "example.net."
-    # second method, close session manually
-    session = requests.sessions.Session()
-    q = dns.message.make_query(qname, dns.rdatatype.A)
-    r = dns.query.https(q, where, session=session)
-    for answer in r.answer:
-        print(answer)
-
-    # ... do more lookups
-
-    # close the session when you're done
-    session.close()
-
 
 if __name__ == "__main__":
     main()