Update README.md with configs/commands to be able to run the example on macOS (prometheus-community#180)

* Update README.md

Updating a few configs/commands to be able to run the example on macOS

Signed-off-by: Vickie <vicky.liu.61@gmail.com>

* Minimize documentation changes

Signed-off-by: rustyclock <rustyclock@protonmail.com>

Signed-off-by: Vickie <vicky.liu.61@gmail.com>
Signed-off-by: rustyclock <rustyclock@protonmail.com>
Co-authored-by: rustyclock <rustyclock@protonmail.com>

Author: turtletree

README.md

@@ -64,8 +64,8 @@ modules:
     headers:
       X-Dummy: my-test-header
 
-$ python -m SimpleHTTPServer 8000 &
-Serving HTTP on 0.0.0.0 port 8000 ...
+$ python3 -m http.server 8000 &
+Serving HTTP on :: port 8000 (http://[::]:8000/) ...
 
 $ ./json_exporter --config.file examples/config.yml &
 
@@ -79,7 +79,7 @@ example_value_count{environment="beta",id="id-A"} 1
 example_value_count{environment="beta",id="id-C"} 3
 
 # To test through prometheus:
-$ docker run --rm -it -p 9090:9090 -v $PWD/examples/prometheus.yml:/etc/prometheus/prometheus.yml --network host prom/prometheus
+$ docker run --rm -it -p 9090:9090 -v $PWD/examples/prometheus.yml:/etc/prometheus/prometheus.yml prom/prometheus
 ```
 Then head over to http://localhost:9090/graph?g0.range_input=1h&g0.expr=example_value_active&g0.tab=1 or http://localhost:9090/targets to check the scraped metrics or the targets.
 

examples/prometheus.yml

@@ -4,13 +4,14 @@ scrape_configs:
 - job_name: prometheus
   static_configs:
     - targets:
-      - localhost:9090
+      - host.docker.internal:9090 # equivalent to "localhost:9090"
 
   ## gather the metrics of json_exporter application itself
 - job_name: json_exporter
   static_configs:
     - targets:
-      - localhost:7979 ## Location of the json exporter's real <hostname>:<port>
+      ## Location of the json exporter's real <hostname>:<port>
+      - host.docker.internal:7979 # equivalent to "localhost:7979"
 
   ## gather the metrics from third party json sources, via the json exporter
 - job_name: json
@@ -28,5 +29,6 @@ scrape_configs:
     - source_labels: [__param_target]
       target_label: instance
     - target_label: __address__
-      replacement: localhost:7979 ## Location of the json exporter's real <hostname>:<port>
+      ## Location of the json exporter's real <hostname>:<port>
+      replacement: host.docker.internal:7979 # equivalent to "localhost:7979"