v1 /write api does not support Basic auth

[jdstrand]

Basic auth is supported in 1.x: https://docs.influxdata.com/influxdb/v1/administration/authentication_and_authorization/#authenticate-with-basic-authentication. Since Core and Enterprise don't have users, they should support basic auth like other non-1.products where the password is the token string and the username is ignored (can be anything).

Telegraf uses Basic authentication when specifying username and password in the v1 influxdb output plugin: https://github.com/influxdata/telegraf/blob/master/plugins/outputs/influxdb/http.go#L503

Steps to reproduce:

On the server:

$ influxdb3 create token
Token: apiv3_...
Hashed Token: 1330b707ff133a46d13ac87a4d678f30703e5bbec5230a325e0fd1ac25ade8a831ad6a5985d5a4c26b722229dcf1c7f50ac810ee81a6363a355b3c66b440733a

$ influxdb3 server ... --bearer-token 1330b707ff133a46d13ac87a4d678f30703e5bbec5230a325e0fd1ac25ade8a831ad6a5985d5a4c26b722229dcf1c7f50ac810ee81a6363a355b3c66b440733a

On the client:

$  export INFLUX_TOKEN="apiv3_..."
$ export INFLUX_BASIC=$(echo -n "ignored:$INFLUX_TOKEN" | base64 -w 0)
$ curl -H "Authorization: Basic $INFLUX_BASIC" -X POST "http://localhost:8181/write?db=test" --data-binary "mymeas,mytag1=sometag value=0.56 $(date +%s%N)"
{"error":"Authorization header was malformed and should be in the form 'Authorization: Bearer <token>'"}

For completeness, all other cases seem to already be supported for v2 /api/v2/write and v1 /write:

# write (v2) - works with Bearer
$  export INFLUX_TOKEN="<token from 'influxdb3 create'>"
$ curl -H "Authorization: Bearer $INFLUX_TOKEN" -X POST "http://localhost:8181/api/v2/write?bucket=test" --data-binary "mymeas,mytag1=sometag value=0.51 $(date +%s%N)"

# write (v2) - works with Token
$ curl -H "Authorization: Token $INFLUX_TOKEN" -X POST "http://localhost:8181/api/v2/write?bucket=test" --data-binary "mymeas,mytag1=sometag value=0.52 $(date +%s%N)"

# write (v1) - works with Bearer
$ curl -H "Authorization: Bearer $INFLUX_TOKEN" -X POST "http://localhost:8181/write?db=test" --data-binary "mymeas,mytag1=sometag value=0.53 $(date +%s%N)"

# write (v1) - works with Token
$ curl -H "Authorization: Token $INFLUX_TOKEN" -X POST "http://localhost:8181/write?db=test" --data-binary "mymeas,mytag1=sometag value=0.54 $(date +%s%N)"

# write (v1) - works with username/password URL params
$ curl -X POST "http://localhost:8181/write?db=test&u=ignored&p=$INFLUX_TOKEN" --data-binary "mymeas,mytag1=sometag value=0.55 $(date +%s%N)"

[jdstrand]

Note to whoever picks this up: with older InfluxDB write paths, only /write (v1) supports Basic auth. /api/v2/write does not.